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Distribution Type – Part 2:

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

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Content 1 I G B; E F B Q E F R S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S T2 C U F E R V W U D E C S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S XY B Z Q E F R [ S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S X1

? W E \ B S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S X2

= E F J I U D ] B F B K B F B C W B [ S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S ^3

5 B K D C D U D E C [ I C R I _ _ F B ] D I U D E C [ S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S `X S a 5 B K D C D U D E C [ S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S `X S T 8 _ _ F B ] D I U D E C [ S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S b4

9 B c V D F B J B C U [ S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S b^ S a ? V J J I F Z E K B I F U H D C G F B c V D F B J B C U [ S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S b^ S T 4 I F U H D C G E K B c V D \ J B C U D C [ U I d d I U D E C [ S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S e^ S X 3 : K B B R B F B I F U H D C G I C R [ B F ] D W B W E C C B W U D E C [ S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S a f^ S ^ 4 I F U H D C G E K 0 : E ] B F H B I R d D C B [ S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S a ^^ S ` 4 I F U H D C G E K W I _ d B [ S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S a ^^ S b 4 I F U H B d B W U F E R B [ S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S a ^^ S g . E C C B W U D E C [ U E B I F U H B d B W U F E R B [ S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S T T^ S e 0 I U B F D I d [ K E F B I F U H D C G I \ \ d D W I U D E C [ S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S T T5

0 B I [ V F B J B C U G V D R B S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S T `` S a 8 \ \ I F I U V [ K E F B I F U H U B [ U [ S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S T `` S T ; I W U E F [ I K K B W U D C G J B I [ V F B J B C U I W W V F I W Z S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S T e` S X ? E D d F B [ D [ U D ] D U Z J B I [ V F B J B C U S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S T h` S ^ 4 I F U H B d B W U F E R B F B [ D [ U I C W B J B I [ V F B J B C U S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S X T` S ` 4 I F U H [ V F K I W B \ E U B C U D I d J B I [ V F B J B C U S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S ^ f` S b 4 I F U H W E C U D C V D U Z U B [ U D C G S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S ^ X8 C C B M 8 i 8 G V D R B U E U H B D R B C U D K D W I U D E C I C R B ] I d V I U D E C E K ] I F D E V [ [ E D d U Z \ B [ S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S ^ ^8 C C B M 6 j 4 d B W U F E R B B C H I C W B J B C U S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S ^ b8 C C B M . i . d I F D K D W I U D E C E K U H B 0 : k 3 : B I F U H D C G \ H D d E [ E \ H Z I U B c V D \ J B C U D C [ U I d d I U D E C [ S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S ` f8 C C B M 5 i . I d W V d I U D E C E K B I F U H D C G W E C R V W U E F W F E [ [ i [ B W U D E C I d I F B I [ S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S ` g8 C C B M 4 i 9 B W E J J B C R B R D C [ U I d d I U D E C F B W E F R I C R 0 : B c V D \ J B C U W E J J D [ [ D E C D C G [ H B B U S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S ` h8 C C B M ; i 3 D [ U E K W E J \ E C B C U I C R R B [ D G C R F I Q D C G [ S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S b ^8 C C B M l j 2 J \ I W U 8 [ [ B [ [ J B C U S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S S b b

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DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

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Compiled By:> = � I J _ V d Bi / ] B F I d d R E W V J B C U F B ] D [ B R Si 4 I F U H D C G E K W I _ d B [ Z [ U B J B c V D \ J B C U Q I [ D C W d V R B R Si 2 C K E F J I U D E C E C U H B D C U B F W E C C B W U D E C E K U H B 3 : R D [ U F D _ V U E F C B V U F I d [ E KV F _ I C I C R E U H B F I \ \ F E \ F D I U B 3 : E ] B F H B I R C B U Q E F � [ U E K E F J I d E QD J \ B R I C W B F B U V F C \ I U H I W W E F R D C G U E ? 8 = ? a f T h T Q I [ D C W d V R B R Si > H B W E J J E C K D B d R \ F E W B R V F B E K U B [ U D C G E K J D C E F Q E F � [ Q I [D C W E F \ E F I U B R Si > H B V C D c V B D R B C U D K D B F E K U H B [ U I C R I F R Q I [ W H I C G B R K F E J ? . ? 8 ? 8 8 3 h U E5 ? > A X ^ i a h e ` Si > H B U D U d B E K U H B [ U I C R I F R Q I [ W H I C G B R K F E J � 0 : I C R 3 : 9 B U D W V d I U D E C4 I F U H D C G � U E � 0 : I C R 3 : 5 D [ U F D _ V U D E C ? Z [ U B J 4 I F U H D C G � S� V d Z a h h h a i

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DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �3 of 69

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5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �4 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

. > k : > 0 B U B F D C G V C D U [ SPole mounted switchgear . D F W V D U i _ F B I � B F [? B W U D E C I d D � B F [Pole/surface mounted compensating equipment ? H V C U W I \ I W D U E F _ I C � [: E d U I G B F B G V d I U E F [Surge arrester installations

NOTE: � o y u � t � u p q q w u s � p � � r v o u w y n � p � u w w u p � o x o p y � v r w o � � � � x o p y t � � y o q � p � r � p y � � � � y r � � � u w o y r � o v r � p q � p � � � �   � ¡¢ ¢ £ � � � � y w � � � y � r p � y u p q u w q � ¤ u w y � � � o � y � r p ¢ ¥ ¦ � � n y � r p q � � y r w � � u w y � � � t u w w o � � � w o x o p y � v r w r � o w n o u q t � p o � � � y r     § ¨ s � y n� r p q � � y r w � � � y r © u w o � r p q � � y r w �

Cable system equipment 0 D C D i [ V _ [ U I U D E C [l F E V C R i J E V C U B R U F I C [ K E F J B F [. > k : > 0 B U B F D C G V C D U [9 D C G J I D C V C D U [ L 9 0 < [ N_ N 0 B R D V J I C R d E Q ] E d U I G B C B U Q E F � [0 B R D V J ] E d U I G B R D [ U F D _ V U D E C d D C B [ S3 E Q ] E d U I G B K B B R B F [ S S0 : I C R 3 : V C R B F G F E V C R W I _ d B C B U Q E F � [ SNOTE 1: ª r w o u w y n � p � w o � � � w o x o p y � r p � � p � t o ¡ s � w o o u w y n w o y � w p � � m ~ | � � � � y o x � � w o v o w y r � � � �   � ¡ � «   � � � � y w � � � y � r p � y u p q u w q �¤ u w y � � � o � y � r p � ¥ � m ~ | � u w y � � � t u w w o � � � w o x o p y � v r w ¢ £ § ¨ � � p � t o s � w o o u w y n w o y � w p � � m ~ | � r � o w n o u q q � � y w � � � y � r p �NOTE 2: ª r w ¦ ¨ � o w � � � o � u � t o o u w y n � p � w o � � � w o x o p y � r p ¦ ¤ ¬ � t u w � o � r s o w � � o w � � u p q � ¤ ¬ � � x u t t � r s o w � � o w � � r � y q r r w� o w � � � o � � w o v o w y r � � � �   � ¡   ­ « � � � � y w � � � y � r p � y u p q u w q � ¤ u w y ® � � o � y � r p   ¥ ¯ � y q r r w ¦ ¨ � o w � � � o � v r w � x u t t � r s o w � � o w � u p q t u w � o� r s o w � � o w � �2 Normative references > H B K E d d E Q D C G R E W V J B C U [ W E C U I D C \ F E ] D [ D E C [ U H I U � U H F E V G H F B K B F B C W B D C U H B U B M U � W E C [ U D U V U B F B c V D F B J B C U [ E KU H D [ [ U I C R I F R S 8 U U H B U D J B E K \ V _ d D W I U D E C � U H B B R D U D E C [ D C R D W I U B R Q B F B ] I d D R S 8 d d [ U I C R I F R [ I C R [ \ B W D K D W I U D E C [I F B [ V _ � B W U U E F B ] D [ D E C � I C R \ I F U D B [ U E I G F B B J B C U [ _ I [ B R E C U H D [ [ U I C R I F R I F B B C W E V F I G B R U E D C ] B [ U D G I U B U H B\ E [ [ D _ D d D U Z E K I \ \ d Z D C G U H B J E [ U F B W B C U B R D U D E C [ E K U H B R E W V J B C U [ d D [ U B R _ B d E Q S? U I C R I F R [ O? 8 = ? a f a h h O T f f ^ � > H B R B [ D G C I C R D C [ U I d d I U D E C E K B I F U H B d B W U F E R B [ S? 8 = ? a f T h T O T f f a � 4 I F U H D C G E K d E Q i ] E d U I G B R D [ U F D _ V U D E C [ Z [ U B J [ S? 8 = ? a f b X O a h h e � 4 I F U H F E R [ I C R W E V \ d B F [ S? 8 = ? a f a h e i X O T f f ^ � > H B [ B d B W U D E C � H I C R d D C G I C R D C [ U I d d I U D E C E K B d B W U F D W \ E Q B F W I _ d B [ E K F I U D C G C E UB M W B B R D C G X X � : S? 8 = ? a ^ a a i g O T f f X � 0 I U B F D I d [ E K D C [ V d I U B R W I _ d B [ I C R K d B M D _ d B W E F R [ j 1 I F U g O 1 E d Z B U H Z d B C B L 1 4 N S? . ? 8 ? 8 6 Y X O 9 B ] S f � 5 D [ U F D _ V U D E C ? U I C R I F R j 1 I F U g O l B C B F D W [ V _ [ U I U D E C R B [ D G C S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �5 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

5 9 1 A X ^ i a h X X � 5 D [ U F D _ V U D E C 9 B \ E F U j / \ U D J D � I U D E C E K 0 : B I F U H B d B W U F E R B R B [ D G C S= 9 ? f f f i a O . E J \ d D W I U D E C E K = 9 ? I C R E U H B F R B K D C D U D E C [ V [ B R D C U H B B d B W U F D W D U Z [ V \ \ d Z D C R V [ U F Z5 ? > A X ^ i a a h T 5 D [ U F D _ V U D E C ? U I C R I F R � 1 I F U ^ � ? B W U D E C a O 3 D G H U W E C R V W U E F [ \ I F U D W V d I F F B c V D F B J B C U [ K E FE ] B F H B I R d D C B [ V \ U E X X � : Q D U H W E C R V W U E F [ V \ U E @ I F B W E C R V W U E F �5 ? > X ^ i a a g ` � 5 D [ U F D _ V U D E C ? U I C R I F R � 1 I F U T T � ? B W U D E C f O l B C B F I d D C K E F J I U D E C I C R F B c V D F B J B C U [ K E F J B R D V J] E d U I G B W I _ d B [ Z [ U B J [ S; D G a j > = i . i ? [ Z [ U B J B I F U H D C G � ? 8 = ? a f T h T O T f f a � 4 I F U H D C G E K d E Q i ] E d U I G B R D [ U F D _ V U D E C [ Z [ U B J [ S3 Definitions and abbreviations

3.1 Definitions > H B R B K D C D U D E C [ I C R I _ _ F B ] D I U D E C [ D C = 9 ? f f f i a I C R U H B K E d d E Q D C G R B K D C D U D E C [ I \ \ d Z Oconductive concrete:

. E C W F B U B W E C [ D [ U D C G E K W B J B C U I C R I C I R R B R B d B W U F E d Z U B U E W E C K E F J U E5 i 5 > i X T f ` S . E C R V W U D ] B W E C W F B U B H I [ I \ \ d D W I U D E C [ D C B I F U H D C G D C I F B I [ Q H B F B U H B [ E D d F B [ D [ U D ] D U Z D [ ] B F Z H D G H Searthing lead (down lead):

> H I U [ B W U D E C E K W E C R V W U E F W E C C B W U D C G I _ V F D B R B I F U H B d B W U F E R B U E D C [ U I d d B RB c V D \ J B C U Selectrode (earth electrode):

/ C B E F J E F B W E C R V W U D ] B \ I F U [ U H I U I F B B J _ B R R B R D C U H B B I F U H K E F U H B \ V F \ E [ BE K J I � D C G B K K B W U D ] B B d B W U F D W I d W E C U I W U Q D U H U H B G B C B F I d J I [ [ E K B I F U H SPEN conductor:

8 W E C R V W U E F U H I U K V C W U D E C [ _ E U H I [ I 1 F E U B W U D ] B 4 I F U H W E C R V W U E F I C R I = B V U F I d W E C R V W U E F SSystem earthing identification code as defined in SANS 10292: > H B K D F [ U d B U U B F E K U H B D R B C U D K D W I U D E C W E R B R B C E U B [ U H B F B d I U D E C [ H D \ E K U H B [ E V F W B E K B C B F G Z U E B I F U H I [K E d d E Q [ O

T – / C B E F J E F B \ I F U [ I F B W E C C B W U B R R D F B W U d Z U E B I F U H S

I –8 d d d D ] B \ I F U [ I F B D [ E d I U B R K F E J B I F U H E F E C B \ E D C U D [ W E C C B W U B R U E B I F U H U H F E V G H I CD J \ B R I C W B S> H B [ B W E C R d B U U B F E K U H B D R B C U D K D W I U D E C W E R B R B C E U B [ U H B F B d I U D E C [ H D \ E K U H B B M \ E [ B R W E C R V W U D ] B\ I F U [ E K U H B W E C [ V J B F � [ D C [ U I d d I U D E C U E B I F U H I [ K E d d E Q [ O

T – B M \ E [ B R W E C R V W U D ] B \ I F U [ E K U H B W E C [ V J B F � [ B d B W U F D W I d D C [ U I d d I U D E C I F B W E C C B W U B R U EB I F U H � D C R B \ B C R B C U d Z E K U H B B I F U H D C G E K I C Z \ E D C U E K U H B [ E V F W B E K B C B F G Z S

Nj > H B B M \ E [ B R W E C R V W U D ] B \ I F U [ E K U H B W E C [ V J B F � [ B d B W U F D W I d D C [ U I d d I U D E C I F B W E C C B W U B RR D F B W U U E U H B [ E V F W B B I F U H � Q H D W H � D C U H B W I [ B E K I C 8 . [ Z [ U B J D [ V [ V I d d Z U H B U F I C [ K E F J B FC B V U F I d \ E D C U S> H B R B [ D G C I U D E C > = D [ K V F U H B F [ V _ R D ] D R B R R B \ B C R D C G E C U H B I F F I C G B J B C U E K U H B C B V U F I d I C R\ F E U B W U D ] B W E C R V W U E F [ S > H I U I F F I C G B J B C U D [ R B C E U B R _ Z I K V F U H B F d B U U B F E F d B U U B F [ � I [ K E d d E Q [ O

C – > H B C B V U F I d I C R \ F E U B W U D ] B K V C W U D E C [ E C U H B 3 : R D [ U F D _ V U E F I C R D C U H B W E C [ V J B F � [B d B W U F D W I d D C [ U I d d I U D E C I F B W E J _ D C B R D C I [ D C G d B W E C R V W U E F S

S –> H B C B V U F I d I C R \ F E U B W U D ] B K V C W U D E C [ E C U H B 3 : R D [ U F D _ V U E F I C R D C U H B W E C [ V J B F � [B d B W U F D W I d D C [ U I d d I U D E C I F B \ F E ] D R B R _ Z [ B \ I F I U B W E C R V W U E F [ S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �6 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

C-S - > H B C B V U F I d I C R \ F E U B W U D ] B K V C W U D E C [ E C U H B 3 : R D [ U F D _ V U E F I F B W E J _ D C B R D C I [ D C G d BW E C R V W U E F I C R D C U H B W E C [ V J B F � [ B d B W U F D W I d D C [ U I d d I U D E C I F B \ F E ] D R B R _ Z [ B \ I F I U BW E C R V W U E F [ S

3.2 Abbreviations

ECC: 4 I F U H W E C U D C V D U Z W E C R V W U E F S

4 Requirements

4.1 Summary of earthing requirements > H B B I F U H D C G \ F I W U D W B I \ \ d D W I _ d B U E V F _ I C I C R F V F I d R D [ U F D _ V U D E C [ Z [ U B J [ D [ R D [ W V [ [ B R _ B d E Q S > H B R D K K B F B C UU Z \ B [ E K R D [ U F D _ V U D E C [ Z [ U B J [ I F B R B K D C B R D C 8 \ \ B C R D M . I C R I d [ E [ B B [ B W U D E C ^ S b S X S a S4.1.1 Earthing at equipment installations

4.1.1.1 > F I C [ K E F J B F 0 : I C R 3 : B I F U H [ J I Z _ B W E J _ D C B R E C d Z Q H B F B U H B D F E ] B F I d d F B [ D [ U I C W B U E B I F U H R E B [C E U B M W B B R a E F Q H B F B U H B F B D [ I C 4 . . L B I F U H W E C U D C V D U Z W E C R V W U E F N _ I W � U E U H B [ E V F W B [ V _ [ U I U D E C S/ U H B F Q D [ B � U H B \ F I W U D W B E K B I F U H D C G D C ] E d ] B [ [ B \ I F I U D E C E K U H B J B R D V J I C R d E Q ] E d U I G B B I F U H [ I U I d dU F I C [ K E F J B F D C [ U I d d I U D E C [ \ F E ] D R D C G I [ V \ \ d Z U E I W V [ U E J B F I U C E J D C I d ] E d U I G B [ V \ U E I C R D C W d V R D C G U H BD C U B F J B R D I U B ] E d U I G B L 2 : N F I C G B � D S B S K E F C E J D C I d ] E d U I G B [ V \ U E I C R D C W d V R D C G a h f f : � [ D C G d B i \ H I [ B I C R XX f f : � U H F B B i \ H I [ B S

4.1.1.2 > H B F B D [ I C B M W B \ U D E C U E U H B G B C B F I d F V d B U H I U U H B 0 : I C R 3 : B I F U H [ J I Z C E U _ B W E J _ D C B R V C d B [ [U H B U E U I d F B [ D [ U I C W B E K U H B W E J _ D C B R B d B W U F E R B U E F B J E U B B I F U H D [ d B [ [ U H I C a E F V C d B [ [ U H B F B D [ I C 4 . ._ I W � U E U H B [ E V F W B [ V _ [ U I U D E C S > H D [ D [ Q H B C I F B J E U B U F I C [ K E F J B F Q E V d R F B c V D F B I ] B F Z B M \ B C [ D ] B 0 : B I F U HB d B W U F E R B U E I W H D B ] B I C 0 : B d B W U F E R B D J \ B R I C W B E K d B [ [ U H I C X f S ; E F U H B \ V F \ E [ B E K U H D [ W d I V [ B � IF B J E U B U F I C [ K E F J B F D [ R B K D C B R I [ I U F I C [ K E F J B F U H I U [ V \ \ d D B [ I [ D C G d B V C J I C C B R D C [ U I d d I U D E C I C R U H BD C [ U I d d I U D E C D [ [ V D U I _ d Z K I F K F E J I C Z \ d I W B Q H B F B \ B E \ d B I F B E K U B C \ F B [ B C U U E B C [ V F B U H I U U H B F D [ � E K I \ B F [ E C_ B D C G D C U H B ] D W D C D U Z E K U H B U F I C [ K E F J B F R V F D C G I C B I F U H K I V d U D [ B M U F B J B d Z d E Q S 2 C U H D [ W I [ B U H B 0 : I C R 3 :B I F U H B d B W U F E R B E K U H B U F I C [ K E F J B F W I C _ B W E J _ D C B R D C U E E C B B d B W U F E R B S > H B W E J _ D C B R B d B W U F E R B D C [ U I d d B R[ H I d d H I ] B [ V K K D W D B C U d Z d E Q D J \ B R I C W B U E I d d E Q U H B [ B C [ D U D ] B B I F U H K I V d U \ F E U B W U D E C U E E \ B F I U B S > H D [ D [ U EB C [ V F B U H I U I K I V d U Q D d d C E U F B J I D C E C U H B C B U Q E F � K E F I C B M U B C R B R \ B F D E R E K U D J B Q H D W H Q E V d R D C W F B I [ B U H BF D [ � E K I \ B F [ E C _ B D C G D C U H B ] D W D C D U Z E K U H B D C [ U I d d I U D E C Q H D d B I K I V d U D [ \ F B [ B C U S > H B d D J D U [ E K U H B B I F U HB d B W U F E R B D J \ B R I C W B U H I U [ H E V d R C E U _ B B M W B B R B R D C E F R B F U E B C [ V F B U H I U U H B [ B C [ D U D ] B B I F U H K I V d U \ F E U B W U D E CQ D d d E \ B F I U B D C U H B B ] B C U E K I K I V d U I F B G D ] B C D C > I _ d B T S

NOTE¥ z p � p q o w � w r � p q � u � t o p o y s r w § � � y n o x o y u t t � � � n o u y n r w u w x r � w � p � r v y n o ° ¨ � u � t o � o p o w u t t � � o w � o � u � u p ~ } } �

4.1.1.3 � H B F B U H B 0 : I C R 3 : B I F U H B d B W U F E R B [ I F B [ B \ I F I U B R I U U F I C [ K E F J B F D C [ U I d d I U D E C [ � U H B U F I C [ K E F J B F � [3 : Q D C R D C G [ [ H I d d _ B \ F E U B W U B R I G I D C [ U D C [ V d I U D E C _ F B I � R E Q C _ Z D C [ U I d d D C G I C B V U F I d [ V F G B I F F B [ U B F _ B U Q B B CU H B 3 : C B V U F I d U B F J D C I d I C R U H B U I C � B I F U H S

4.1.1.4 8 J D C D J V J [ B \ I F I U D E C R D [ U I C W B E K ` J [ H I d d _ B J I D C U I D C B R _ B U Q B B C U H B 0 : I C R 3 : B I F U HB d B W U F E R B [ I U U F I C [ K E F J B F D C [ U I d d I U D E C [ S

4.1.1.5 ; E F I d d E U H B F B c V D \ J B C U D C [ U I d d I U D E C [ D C I R D [ U F D _ V U D E C [ Z [ U B J I [ D C G d B B I F U H B d B W U F E R B D [ F B c V D F B R S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �7 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

4.1.2 LV feeder earthing and service connections

4.1.2.1 3 : R D [ U F D _ V U D E C [ Z [ U B J [ [ H I d d _ B B I F U H B R D C I W W E F R I C W B Q D U H U H B > = i . i ? B I F U H D C G [ Z [ U B J\ H D d E [ E \ H Z � D S B S U H B C B V U F I d I C R \ F E U B W U D ] B K V C W U D E C [ I F B W E J _ D C B R D C I [ D C G d B W E C R V W U E F _ B U Q B B C U H B [ E V F W BI C R \ E D C U E K [ V \ \ d Z I C R I F B [ B \ I F I U B R D C I W E C [ V J B F � [ D C [ U I d d I U D E C L [ B B ? 8 = ? a f T h T N S

4.1.2.2 2 C V F _ I C R D [ U F D _ V U D E C [ Z [ U B J [ D U D [ E K U B C W E C ] B C D B C U U E B I F U H U H B 0 : I U U H B U F I C [ K E F J B F I C R U H B 3 :F B J E U B d Z L E C B [ \ I C I Q I Z E C U H B 3 : K B B R B F N S � H B F B U H D [ U B W H C D c V B D [ D J \ d B J B C U B R I C R J V d U D \ d B 3 : K B B R B F [D [ [ V B K F E J I U F I C [ K E F J B F [ U F V W U V F B � I d d E K U H B K B B R B F [ [ H I d d _ B B I F U H B R E C B [ \ I C I Q I Z K F E J U H B U F I C [ K E F J B F S

4.1.3 Earth electrodes

4.1.3.1 > H B D J \ B R I C W B E K U H B B I F U H B d B W U F E R B W E C C B W U D E C [ H I d d _ B Q D U H D C U H B d D J D U [ [ \ B W D K D B R D C ^ S T S g S 8 d dB M W B \ U D E C [ � D S B S D C [ U I d d I U D E C [ Q H B F B J I M D J V J B K K E F U R E B [ C E U [ I U D [ K Z U H B J D C D J V J F B c V D F B J B C U [ � [ H I d d _ BF B W E F R B R _ Z 1 F E � B W U 4 C G D C B B F D C G I C R _ B J I R B I ] I D d I _ d B K E F D C ] B [ U D G I U D E C Q H B C B ] B F F B c V D F B R S

4.1.3.2 8 R B U I D d B R D C [ U I d d I U D E C F B W E F R D C W d V R D C G U H B B I F U H D C G I F F I C G B J B C U [ H I d d _ B � B \ U _ Z 1 F E � B W U4 C G D C B B F D C G S 0 I D C U B C I C W B [ H I d d _ B _ I [ B R E C U H B \ F D C W D \ d B E K \ d I C U W E C R D U D E C J E C D U E F D C G I C R [ H I d d _ B W I F F D B RE V U D C I W W E F R I C W B Q D U H 4 [ � E J J I D C U B C I C W B G V D R B d D C B [ S

4.1.3.3 > H B _ V F D B R B I F U H D C G W E C R V W U E F I C R B I F U H F E R [ [ H I d d _ B I U d B I [ U f � ` J _ B d E Q C E F J I d G F E V C R d B ] B d S

4.1.3.4 4 I F U H B d B W U F E R B [ J I Z _ B B C W I [ B R D C W E C R V W U D ] B W E C W F B U B U E F B R V W B U H B R D J B C [ D E C [ E K I F B c V D F B RW E C K D G V F I U D E C S / Q D C G U E U H B H D G H I \ \ d D W I U D E C W E [ U [ � W E C R V W U D ] B W E C W F B U B [ H I d d _ B I \ \ d D B R _ Z B M W B \ U D E C S

4.1.3.5 > H B V [ B E K W H B J D W I d [ U E D J \ F E ] B d E C G U B F J B d B W U F E R B F B [ D [ U I C W B U E B I F U H [ H I d d _ B I \ \ d D B R _ ZB M W B \ U D E C U E I ] E D R I C V C C B W B [ [ I F Z _ V F R B C _ B D C G \ d I W B R E C E \ B F I U D C G I C R J I D C U B C I C W B [ U I K K K E F K E d d E Q V \I \ \ d D W I U D E C [ S

4.1.4 Material for earthing applications

4.1.4.1 ; E F U F I C [ K E F J B F I C R B c V D \ J B C U D C [ U I d d I U D E C [ W E \ \ B F B I F U H d B I R [ U E [ V D U U H B J I M D J V J [ H E F U W D F W V D Ud B ] B d B M \ B W U B R Q D U H D C U H B [ Z [ U B J [ H I d d _ B V [ B R S ? E d D R W E \ \ B F W E C R V W U E F E K I J D C D J V J a T J J ± W F E [ [ [ B W U D E CE F [ U F I C R B R W E \ \ B F W E C R V W U E F E K I J D C D J V J E K a b J J ± W F E [ [ [ B W U D E C [ H I d d _ B V [ B R S ? B B ^ S e S a S a S K E F J E F BD C K E F J I U D E C S

4.1.4.2 . E \ \ B F i W d I R [ U B B d W E C R V W U E F [ J I Z _ B V [ B R K E F B I F U H D C G I \ \ d D W I U D E C [ D C I F B I [ Q H B F B W E \ \ B F U H B K U D [I \ F E _ d B J S ? B B ^ S e S a S T K E F J E F B D C K E F J I U D E C S

4.1.4.3 1 : . D C [ V d I U B R B I F U H d B I R [ [ H I d d _ B V [ B R U E E _ U I D C U H B ` J [ B \ I F I U D E C _ B U Q B B C U H B 0 : I C R 3 :B d B W U F E R B [ I U I U F I C [ K E F J B F \ E d B S > H B B I F U H W E C C B W U D C G W E C R V W U E F [ [ H I d d _ B D C [ V d I U B R E ] B F U H B K V d d [ B \ I F I U D E CR D [ U I C W B _ B U Q B B C B d B W U F E R B [ S

NOTE: ª r w � u � t o p o y s r w § � � � v y n o ¦ ¨ x o y o w � u p o t � � t o � � y n u p « x u s u � v w r x y n o y w u p � v r w x o w � y n o p y n o � � � y r x o w ² � ¦ ¨ ~ } } � � vu � � t � � u � t o � � n u t t � o � p � � t u y o q v r w u y t o u � y « x �4.1.4.4

8 d d U H B F B d B ] I C U R B [ D G C R F I Q D C G [ I F B d D [ U B R I C R D C W d V R B R D C I C C B M ; S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �8 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

4.2 Earthing of equipment installations

4.2.1 General installations 8 d d I W W B [ [ D _ d B W E C R V W U E F [ � \ E F U D E C [ E K B d B W U F D W I d \ d I C U E F I \ \ I F I U V [ Q H D W H R E C E U K E F J \ I F U E K I C B d B W U F D W I dW D F W V D U I C R Q H D W H J D G H U _ B W E J B I d D ] B I W W D R B C U I d d Z � [ H I d d _ B _ E C R B R U E B I F U H S4.2.2 Transformer installations 5 D [ U F D _ V U D E C B c V D \ J B C U I [ [ E W D I U B R Q D U H U F I C [ K E F J B F D C [ U I d d I U D E C [ U H I U D [ B D U H B F G F E V C R i J E V C U B R E F \ E d B iJ E V C U B R I C R K B R _ Z V C R B F G F E V C R W I _ d B E F E ] B F H B I R d D C B � [ H I d d _ B D C [ U I d d B R � W E C C B W U B R I C R B I F U H B R D CI W W E F R I C W B Q D U H U H B K E d d E Q D C G F B c V D F B J B C U [ OI N U H B [ U I F \ E D C U E K U H B U F I C [ K E F J B F 3 : Q D C R D C G [ H I d d _ B B I F U H B R L [ B B I d [ E ^ S X N ³_ N U H B 0 : [ V F G B I F F B [ U B F [ � U F I C [ K E F J B F U I C � I C R E U H B F J B U I d Q E F � [ H I d d _ B _ E C R B R U E U H B 0 : B I F U HB d B W U F E R B L [ B B 5 i 5 > i f b T g K E F \ E d B i J E V C U B R U F I C [ K E F J B F [ � 5 i 5 > i f e ` ` K E F J D C D i [ V _ [ U I U D E C [ I C R5 i 5 > i f e b T K E F G F E V C R i J E V C U B R U F I C [ K E F J B F [ N ³W N I W E J _ D C B R 0 : k 3 : B I F U H B d B W U F E R B J I Z _ B B J \ d E Z B R E C d Z Q H B F B U H B B d B W U F E R B F B [ D [ U I C W B U EB I F U H R E B [ C E U B M W B B R a E F Q H B F B U H B F B D [ I C 4 . . _ I W � U E U H B [ E V F W B [ V _ [ U I U D E C E F K E F F B J E U B[ V \ \ d D B [ L [ B B W d I V [ B ^ S a S a S T N ³R N Q H B F B [ B \ I F I U B 0 : I C R 3 : B I F U H [ I F B V [ B R OU H B 0 : I C R 3 : B I F U H B d B W U F E R B [ [ H I d d _ B [ B \ I F I U B R _ Z C E U d B [ [ U H I C ` J �I C B V U F I d [ V F G B I F F B [ U B F D C I W W E F R I C W B Q D U H 5 i 5 > i X f e e [ H I d d _ B D C [ U I d d B R _ B U Q B B C U H B 3 :C B V U F I d U B F J D C I d I C R U H B U F I C [ K E F J B F U I C � � I C RW I F B [ H I d d _ B B M B F W D [ B R U E B C [ V F B U H I U U H B F B D [ C E J B U I d d D W E F E U H B F d E Q D J \ B R I C W B W E C R V W U D C G\ I U H _ B U Q B B C U H B 0 : I C R 3 : B I F U H [ �B N I C B c V D \ E U B C U D I d 0 : B I F U H d E E \ [ H I d d _ B D C [ U I d d B R K E F J D C D i [ V _ [ U I U D E C [ I C R K E F G F E V C R i J E V C U B RU F I C [ K E F J B F I \ \ d D W I U D E C [ D F F B [ \ B W U D ] B E K Q H B U H B F U H B 0 : I C R 3 : B I F U H [ I F B [ B \ I F I U B R E F C E U S > H D [[ H I d d _ B R E C B D C I W W E F R I C W B Q D U H 5 i 5 > i f e ` ` I C R 5 i 5 > i f e b T � F B [ \ B W U D ] B d Z S ; V F U H B F R B U I D d [ W I C_ B K E V C R D C 5 ? > X ^ i a a g ` � 5 D [ U F D _ V U D E C ? U I C R I F R � 1 I F U T T � ? B W U D E C f O l B C B F I d D C K E F J I U D E C I C RF B c V D F B J B C U [ K E F J B R D V J ] E d U I G B W I _ d B [ Z [ U B J [ � W d I V [ B ^ S g S> H B \ H D d E [ E \ H Z F B G I F R D C G U H B I \ \ d D W I U D E C E K W E J _ D C B R E F [ B \ I F I U B R 0 : I C R 3 : B I F U H [ I U U F I C [ K E F J B FD C [ U I d d I U D E C [ D [ \ F E ] D R B R D C I C C B M . S4.2.3 Pole-mounted switchgear, CT/VT metering units, voltage regulators and shunt

capacitors > H B B I F U H D C G [ Z [ U B J K E F \ E d B i J E V C U B R [ Q D U W H G B I F � . > k : > J B U B F D C G V C D U [ � ] E d U I G B F B G V d I U E F [ I C R [ H V C UW I \ I W D U E F [ [ H I d d W E C [ D [ U E K I J V d U D \ d B [ \ D � B B d B W U F E R B L \ F B K B F I _ d Z I U H F B B \ E D C U [ U I F N Q D U H I d d W E C C B W U D E C [_ B D C G J I R B I C R _ E C R B R U E U H B J I D C B I F U H D C G d B I R L [ B B 5 i 5 > i f b ^ T N S > H B W E C C B W U D E C d B I R [ [ H I d d J I U W H U H B[ H E F U U D J B F I U D C G E K U H B J I D C B I F U H D C G d B I R S; V F U H B F R B U I D d [ I C R R F I Q D C G [ E K B I F U H D C G I F F I C G B J B C U [ K E F \ E d B i J E V C U B R [ Q D U W H G B I F � J B U B F D C G I C RW E J \ B C [ I U D C G B c V D \ J B C U I F B U E _ B K E V C R D C 5 ? > A X ^ i a a h T 5 D [ U F D _ V U D E C ? U I C R I F R � 1 I F U ^ � ? B W U D E C a O 3 D G H UW E C R V W U E F [ \ I F U D W V d I F F B c V D F B J B C U [ K E F E ] B F H B I R d D C B [ V \ U E X X � : Q D U H W E C R V W U E F [ V \ U E @ I F B W E C R V W U E F S; E F 3 : [ B F ] D W B W I _ d B B I F U H D C G F B c V D F B J B C U [ E C d I F G B \ E Q B F V [ B F [ L 3 1 < N I C R [ J I d d \ E Q B F V [ B F [ L ? 1 < NE V U R E E F [ B F ] D W B [ � F B K B F U E 5 ? > A X ^ i X f ` � 5 D [ U F D _ V U D E C ? U I C R I F R � 1 I F U e � ? B W U D E C X O / V U R E E F 3 : [ B F ] D W B [ K E F[ J I d d \ E Q B F V [ B F [ I C R d I F G B \ E Q B F V [ B F [ SNOTE: ª r w w o � t r � o w � p � y u t t u y � r p � � � v u � � p � t o ¡ � n u � o y w u p � v r w x o w � � � � o q � p � y o u q r v u ¨ � � � y � n u t t � o o u w y n o q u � � r w q � p � y r � ¡ � � ¡¢ ® � « � � p ¡ t � p o � u p q � ¡ � � ¡ ¢ ® � £ � r � y ¡ r v ¡ t � p o � �

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �9 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

4.2.4 Surge arrester installations ? V F G B I F F B [ U B F D C [ U I d d I U D E C [ [ H I d d _ B B I F U H B R I [ K E d d E Q [ OI N U H B B I F U H D C G [ Z [ U B J [ H I d d W E C [ D [ U E K I J V d U D \ d B F E R B d B W U F E R B L \ F B K B F I _ d Z I U H F B B \ E D C U [ U I F N Q D U H I d dW E C C B W U D E C [ _ B D C G J I R B I C R _ E C R B R U E U H B J I D C B I F U H D C G d B I R ³_ N U H B [ V F G B I F F B [ U B F [ [ H I d d _ B W E C C B W U B R U E B I F U H I C R U E U H B B c V D \ J B C U _ B D C G \ F E U B W U B R _ Z U H B[ H E F U B [ U \ E [ [ D _ d B I C R J E [ U \ F I W U D W I d R D F B W U F E V U B ³W N I d d I F F B [ U B F [ [ H I d d _ B \ F E ] D R B R Q D U H R B ] D W B [ K E F R D [ W E C C B W U D C G U H B I F F B [ U B F [ D C U H B B ] B C U E K K I D d V F B S> H B B I F U H W E C C B W U D E C [ H I d d _ B K d B M D _ d B B C E V G H U E I d d E Q U H B R D [ W E C C B W U D C G R B ] D W B U E _ d E Q W d B I F E KU H B I F F B [ U B F ³ I C RR N [ V F G B I F F B [ U B F [ [ H I d d _ B D C [ U I d d B R Q H B F B I W I _ d B D [ W E C C B W U B R U E I C E ] B F H B I R d D C B S > H B W I _ d BU B F J D C I U D E C B I F U H [ U F I \ I C R I F F B [ U B F B I F U H U I D d [ [ H I d d _ B _ E C R B R U E G B U H B F S4.2.5 Mini-substation and ground-mounted transformer installations 0 D C D i [ V _ [ U I U D E C [ I C R G F E V C R i J E V C U B R U F I C [ K E F J B F [ [ H I d d _ B B I F U H B R I W W E F R D C G U E 5 ? > A X ^ i a a g ` �5 D [ U F D _ V U D E C ? U I C R I F R � 1 I F U T T � ? B W U D E C f O l B C B F I d D C K E F J I U D E C I C R F B c V D F B J B C U [ K E F J B R D V J ] E d U I G B W I _ d B[ Z [ U B J [ S 8 C B c V D \ E U B C U D I d d E E \ I F E V C R U H B \ d D C U H D [ I d Q I Z [ F B c V D F B R K E F E \ B F I U E F [ I K B U Z S4.2.6 Ring Main Units (ground-mounted switchgear) and CT/VT metering equipment

installations > H B B I F U H D C G [ Z [ U B J K E F F D C G J I D C V C D U [ I C R . > k : > J B U B F D C G B c V D \ J B C U D [ [ D J D d I F U E U H I U E K \ E d B i J E V C U B R[ Q D U W H G B I F B M W B \ U U H I U C E B I F U H B d B W U F E R B D [ F B c V D F B R D K U H B F B D [ I C 4 . . _ I W � U E U H B [ E V F W B [ V _ [ U I U D E C L [ B B5 i 5 > i f e b ` N S > H B B c V D \ J B C U [ H I d d _ B B I F U H B R I W W E F R D C G U E 5 ? > A X ^ i a a g ` � 5 D [ U F D _ V U D E C ? U I C R I F R � 1 I F U T T �? B W U D E C f O l B C B F I d D C K E F J I U D E C I C R F B c V D F B J B C U [ K E F J B R D V J ] E d U I G B W I _ d B [ Z [ U B J [ S 8 C B c V D \ E U B C U D I d d E E \I F E V C R U H B \ d D C U H D [ I d Q I Z [ F B c V D F B R K E F E \ B F I U E F [ I K B U Z S4.2.7 Specific resistance values of the equipment earths > H B R B F D ] I U D E C [ E K F B [ D [ U I C W B ] I d V B [ [ \ B W D K D B R D C U H D [ [ B W U D E C I F B D C W d V R B R D C I C C B M . S4.2.7.1

> F I C [ K E F J B F B I F U H B d B W U F E R B [4.2.7.1.1

> F I C [ K E F J B F 0 : B I F U H B d B W U F E R B; E F _ E U H T T � : I C R a a � : 0 : [ Z [ U B J [ � U H B J I M D J V J I d d E Q I _ d B F B [ D [ U I C W B E K U H B U F I C [ K E F J B F 0 : B I F U HB d B W U F E R B D [ X f S > H D [ d D J D U Q D d d B C [ V F B U H I U K E F I 0 : d D C B U E U F I C [ K E F J B F U I C � K I V d U OI N C E R I C G B F E V [ ] E d U I G B [ I F B B M \ B F D B C W B R E C U H B 3 : C B V U F I d ³_ N U H B 3 : C B V U F I d [ V F G B I F F B [ U B F B C B F G Z I _ [ E F \ U D E C d D J D U [ I F B C E U B M W B B R B R ³ I C RW N [ V K K D W D B C U K I V d U W V F F B C U K d E Q [ U E E \ B F I U B U H B 0 : B I F U H K I V d U \ F E U B W U D E C S4.2.7.1.2

> F I C [ K E F J B F 3 : B I F U H B d B W U F E R B> H B E ] B F I d d F B [ D [ U I C W B U E B I F U H E K U H B 3 : B d B W U F E R B I U U H B U F I C [ K E F J B F [ H I d d _ B [ V W H I [ U E B C [ V F B U H I U U H BK B B R B F J I D C B I F U H K I V d U \ F E U B W U D E C I U U H B [ E V F W B Q D d d E \ B F I U B D C B ] B C U E K I _ F B I � R E Q C _ B U Q B B C U H B 0 : I C R3 : Q D C R D C G [ E K U H B U F I C [ K E F J B F S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �10 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

> H B K E d d E Q D C G J I M D J V J F B [ D [ U I C W B [ I \ \ d Z U E U H B U F I C [ K E F J B F 3 : B d B W U F E R B OTable 1 – Maximum earth resistance values for transformer LV electrodes

Main earth fault protection setting ´ µ ¶

Transformer primary

· ¸

Transformer primary � � · ¸

Maximum resistance value ́¶ � � ¹ � º �» � ¼ � ¹ �½ � � � » � � � � � �

NOTE:{ v u � y r w r v � u v o y � r v u � � w r ¾ � x u y o t � � n u � � o o p � � o q y r o p � � w o u � � o � y u � t o � w r y o � y � r pr � o w u y � r p � p q o w ¥u � � o u � r p u t � u w � u y � r p � � p � r � t w o � � � y � � � y � � u p q� � � u w � u y � r p � � p y n o o v v o � y � � o p o � � r v ° ¨ � r � w � o o u w y n � p � �> H B F B [ D [ U I C W B ] I d V B [ D C > I _ d B a R E C E U I \ \ d Z U E [ D C G d B Q D F B B I F U H F B U V F C L ? � 4 9 N R D [ U F D _ V U D E C [ Z [ U B J [ S2 K U H B J I M D J V J ] I d V B [ K E F U H B 0 : I C R 3 : B d B W U F E R B [ W I C C E U _ B I W H D B ] B R Q D U H U H B [ U I C R I F R B d B W U F E R BW E C K D G V F I U D E C [ U H B 1 F E � B W U 4 C G D C B B F D C G 5 B \ I F U J B C U [ H I d d _ B F B c V B [ U B R U E D C ] B [ U D G I U B I d U B F C I U D ] B [ � [ V W H I [[ B U U D C G \ F E U B W U D E C U E I d E Q B F E \ B F I U D C G U H F B [ H E d R E F \ F E ] D R D C G I R R D U D E C I d B I F U H D C G S > H B B M \ B C R D U V F B E KB M E F _ D U I C U I J E V C U [ E K J E C B Z E C I R R D U D E C I d B I F U H D C G U E I W H D B ] B U H B [ B ] I d V B [ [ H E V d R _ B I ] E D R B R S 2 C I C C B M 6\ E [ [ D _ d B J B U H E R [ U E B C H I C W B U H B B I F U H B d B W U F E R B I F B I d [ E R D [ W V [ [ B R S

4.2.7.2 4 I F U H B d B W U F E R B [ K E F E U H B F B c V D \ J B C U8 U B c V D \ J B C U D C [ U I d d I U D E C [ E U H B F U H I C U F I C [ K E F J B F [ � K E F B M I J \ d B � \ E d B i J E V C U B R [ Q D U W H G B I F I C R [ V F G BI F F B [ U B F D C [ U I d d I U D E C [ � U H B J I M D J V J B d B W U F E R B F B [ D [ U I C W B ] I d V B [ I F B R B U B F J D C B R _ Z U H B [ B C [ D U D ] B B I F U H K I V d U\ F E U B W U D E C [ B U U D C G [ [ H E Q C D C > I _ d B T S

Table 2 – Maximum earth resistance values for electrodes at other equipment

Sensitive earth fault protection setting ´ µ ¶ Nominal voltage · ¸

Nominal voltage � � · ¸

Maximum resistance value ́¶ º ¼ � � ½ � � � º � ¼ � �

NOTE: 1{ � u v o y � v u � y r w r v u � � w r ¾ � x u y o t � � n u � � o o p � � o q v r w y n o w o u � r p � � � � o p � p y u � t o ¢ �

NOTE 2: � � p � o � o p � � y � � o o u w y n ¡ v u � t y � w r y o � y � r p � � p r y � � o q � p � u � t o p o y s r w § � � v r w � w r � p q ¡ x r � p y o q o � � � � x o p y � r y n o w y n u py w u p � v r w x o w � � � � o q � p y n o � o p o y s r w § � � s n o w o y n o w o � � p r ~ } } � y n o o u w y n o t o � y w r q o w o � � � y u p � o � u t � o � � n u t t � o � p u � � r w q u p � os � y n y n o w o � � � w o x o p y � r v y u � t o ¢ u p q u w o y n o w o v r w o � u � o q r p y n o x u � p o u w y n v u � t y � w r y o � y � r p � o y y � p � � �4.3 LV feeder earthing and service connections

4.3.1 Low voltage feeders > H B B I F U H D C G \ F I W U D W B K E F 3 : K B B R B F [ B J \ d E Z [ I > = i . i ? B I F U H B R [ Z [ U B J Q D U H U H B K E d d E Q D C G W H I F I W U B F D [ U D W [ OI N U H B [ V \ \ d Z D [ B I F U H B R I U U H B [ E V F W B I C R U H B \ F E U B W U D ] B B I F U H I C R C B V U F I d W E C R V W U E F [ I F B W E J _ D C B R ³_ N U H B E ] B F I d d F B [ D [ U I C W B U E B I F U H E K U H B 3 : C B V U F I d [ H I d d C E U B M W B B R U H B ] I d V B [ G D ] B C D C ^ S T S g S a S T ³

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �11 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

W N U H B K E d d E Q D C G J B U H E R [ J I Z _ B V [ B R U E B I F U H U H B 3 : C B V U F I d L [ B B 5 i 5 > i f b X g K E F E ] B F H B I R d D C B [ �5 i 5 > i f e ` ` K E F J D C D i [ V _ [ U I U D E C [ I C R 5 i 5 > i f e b T K E F G F E V C R i J E V C U B R U F I C [ K E F J B F [ N ³U H B 3 : B I F U H B d B W U F E R B J I Z _ B D C [ U I d d B R I U U H B U F I C [ K E F J B F � D C Q H D W H W I [ B D C [ V d I U B R B I F U Hd B I R [ [ H I d d _ B V [ B R U E E _ U I D C U H B ` J [ B \ I F I U D E C � E FU H B 3 : B I F U H B d B W U F E R B J I Z _ B D C [ U I d d B R E C B [ \ I C I Q I Z K F E J U H B U F I C [ K E F J B F S � H B F BJ V d U D \ d B 3 : K B B R B F [ D [ [ V B K F E J I U F I C [ K E F J B F [ U F V W U V F B � B I W H K B B R B F [ H I d d _ B B I F U H B R E C B[ \ I C I Q I Z K F E J U H B U F I C [ K E F J B F S 4 ] B F Z 3 : B I F U H B d B W U F E R B [ H I d d W E J \ d Z Q D U H U H B F B [ D [ U I C W BF B c V D F B J B C U [ [ U I U B R D C ^ S T S b �NOTE: ª r w r � o w n o u q t � p o � � u t y o w p u y � � o ¢ � � y n o � w o v o w w o q x o y n r q r v o u w y n � p � y n o ¦ ¨ p o � y w u t �q � K E F E ] B F H B I R d D C B [ � Q H B F B U H B F B c V D F B R ] I d V B [ E K F B [ D [ U I C W B W I C C E U _ B I U U I D C B R � U H B 1 4 =L W E J _ D C B R B I F U H I C R C B V U F I d N W E C R V W U E F J I Z _ B B I F U H B R I U E U H B F \ E D C U [ I d E C G U H B 3 : K B B R B F ³B N K E F E ] B F H B I R d D C B [ � D C I F B I [ Q H B F B U H B K U E K W E \ \ B F D [ I \ F E _ d B J � I F B R V C R I C U 3 : B I F U H B d B W U F E R B[ H I d d _ B D C [ U I d d B R E C U H B 3 : C B V U F I d S > H B F B R V C R I C U B d B W U F E R B [ H I d d _ B [ D U V I U B R I Q I Z K F E J U H BJ I D C B d B W U F E R B I C R [ H I d d W E J \ d Z Q D U H U H B F B [ D [ U I C W B F B c V D F B J B C U [ [ U I U B R D C ^ S T S b SK N D K U H B 1 4 = W E C R V W U E F D [ _ F E � B C � R I C G B F E V [ ] E d U I G B [ U E B I F U H J I Z B M D [ U I U U H B W E C [ V J B F � [ B I F U HU B F J D C I d S 2 U D [ U H B F B K E F B B [ [ B C U D I d U E \ I Z \ I F U D W V d I F I U U B C U D E C U E U H B W E C R V W U E F � [ D C U B G F D U Z U H F E V G H E V UU H B R B [ D G C � W E C [ U F V W U D E C � J I D C U B C I C W B I C R E \ B F I U D E C E K U H B 3 : R D [ U F D _ V U D E C [ Z [ U B J ³G N K E F E ] B F H B I R d D C B [ � I d d > i E K K W E C C B W U D E C [ K F E J U H B K B B R B F 1 4 = W E C R V W U E F [ H I d d _ B J I R B V [ D C G U Q ED C [ V d I U D E C \ D B F W D C G W E C C B W U E F [ L 2 1 . [ N S 1 l W d I J \ [ [ H I d d _ B V [ B R E C d Z K E F U H B W E C C B W U D E C E KI d V J D C D V J W E C R V W U E F [ U E I d V J D C D V J W E C R V W U E F [ S � H B F B V [ B R � U Q E 1 l W d I J \ [ [ H I d d _ B V [ B R \ B FW E C C B W U D E C SH N I d d J B U I d Q E F � � I W W B [ [ D _ d B K F E J G F E V C R d B ] B d � K E F J D C G \ I F U E K U H B 3 : K B B R B F B M U B F C I d U E U H B[ V _ [ U I U D E C � [ H I d d _ B _ E C R B R U E U H B K B B R B F 1 4 = W E C R V W U E F S > H D [ D C W d V R B [ W I U W H G V I F R [ � J B U I d\ E d B [ � W I _ d B [ H B I U H D C G I C R I F J E V F D C G � J B U I d B C W d E [ V F B [ E K J B U B F [ I C R K V [ B W I _ D C B U [ B U W ³D N C E W D F W V D U i _ F B I � B F [ � D [ E d I U E F [ � K V [ B [ � [ Q D U W H B [ E F F B J E ] I _ d B d D C � [ [ H I d d _ B D C [ U I d d B R D C U H B B I F U HW E C R V W U E F E K U H B 3 : [ V \ \ d Z K B B R B F ³� N D C [ D C G d B i \ H I [ B E ] B F H B I R [ Z [ U B J [ U H B W F E [ [ [ B W U D E C I d I F B I E K U H B 1 4 = W E C R V W U E F E K I d d U H B 3 :K B B R B F [ [ H I d d C E U _ B d B [ [ U H I C U H I U E K U H B \ H I [ B W E C R V W U E F S 2 C U H F B B i \ H I [ B E ] B F H B I R [ Z [ U B J [ U H BW F E [ [ [ B W U D E C I d I F B I E K U H B 1 4 = W E C R V W U E F J I Z _ B F B R V W B R U E H I d K U H I U E K I \ H I [ B W E C R V W U E F S> H B 1 4 = W E C R V W U E F [ H I d d H I ] B I J D C D J V J W F E [ [ [ B W U D E C I d I F B I E K a b J J T ³� N U H B 1 4 = W E C R V W U E F [ H I d d _ B D C [ V d I U B R K F E J U H B U F I C [ K E F J B F U I C � U E \ F B ] B C U W E C U I W U _ B U Q B B C U H B0 : I C R 3 : B I F U H [ ³ I C Rd N U H B 1 4 = W E C R V W U E F D [ W E C C B W U B R U E U H B W E C [ V J B F � [ J I D C B I F U H D C G U B F J D C I d ] D I U H B [ B F ] D W B W I _ d B SJ N < F _ I C I C R E U H B F I \ \ F E \ F D I U B d E Q ] E d U I G B E ] B F H B I R C B U Q E F � [ J I Z D C U B F W E C C B W U 3 : R D [ U F D _ V U E FC B V U F I d [ U E K E F J I d E Q D J \ B R I C W B F B U V F C \ I U H S > H D [ J D U D G I U B [ U H B F D [ � E K K d E I U D C G C B V U F I d k B I F U H] E d U I G B [ R V B U E _ F E � B C C B V U F I d W E C R V W U E F [ E F \ E E F � E D C U D C U B G F D U Z I W F E [ [ U H B W E C [ V J B F � [ [ V \ \ d Z S� H B F B U H D [ D [ D J \ d B J B C U B R � U H B F B D [ I \ E U B C U D I d D C W F B I [ B D C E \ B F I U D C G F D [ � Q H B C R D [ W E C C B W U D C G E FW E C C B W U D C G C B V U F I d [ E K I \ \ I F B C U ¿ R B I R À W D F W V D U [ S ; D B d R [ B F ] D W B E \ B F I U E F [ [ H E V d R _ B W E C [ V d U B R I C RU H B U B W H C D c V B R E W V J B C U B R _ B K E F B I \ \ d Z D C G E C I C Z \ F E � B W U S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �12 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

8 > = i . i ? B I F U H D C G [ Z [ U B J D [ D d d V [ U F I U B R D C ; D G V F B a S Á ÂÁ ÃÁ ÄÅÁÆ Ç È É Ê Ë Ì Í Î É Í Ï Î Ð Ñ Ñ Ð Î É Ò Í

Æ Ó Ê Ò Ï Ì Ô Õ Ò Í Ô È Õ Î É Ö Ì Ê Ð × Î Ï Ø É Í Ù Ñ Ì Ú Ê Û Ð Ï ÌÜ Æ Å Õ Ð Ý Ñ ÌØ Ò È × Õ Ì Ì Ð × Î ÛØ Ò È × Õ Ì Ò Þ Ì Í Ì × Ù ß

Á ÄÁ ÃÁ ÂÜ Æ Å Õ Ð Ý Ñ Ì

à Ò Ë Ý É Í Ì Ô Ì Ð × Î Û á Í Ì È Î × Ð Ñâ Ü Æ Å ã Õ Ò Í Ô È Õ Î Ò × à Ò Í Ï È Ë Ì × Ì Ð × Î ÛÎ Ì × Ë É Í Ð Ñà Ò Ë Ý É Í Ì Ô Ê × Ò Î Ì Õ Î É Ö ÌÌ Ð × Î Û Ð Í Ô Í Ì È Î × Ð Ñâ Ü Æ Å ã Õ Ò Í Ô È Õ Î Ò ×ä Ô Ô É Î É Ò Í Ð Ñ Ì Ð × Î Û ÏÉ Þ × Ì Ç È É × Ì Ô

à Ò Ë Ý É Í Ì Ô Ê × Ò Î Ì Õ Î É Ö ÌÌ Ð × Î Û Ð Í Ô Í Ì È Î × Ð Ñâ Ü Æ Å ã Õ Ò Í Ô È Õ Î Ò ×Æ

Figure 1 – TN-C-S earthing system

NOTE 1: � n o p o � y w u t u p q � w r y o � y � � o v � p � y � r p � u w o � r x � � p o q � p u � � p � t o � r p q � � y r w � o y s o o p y n o � r � w � o u p q y n o � r � p y r v � � � � t � �NOTE 2:

{ t t o ¾ � r � o q � r p q � � y � � o � u w y � r v u p o t o � y w � � u t � p � y u t t u y � r p y n u y � u p � o � r x o u t � � o u w o � r p p o � y o q y r y n o � r x � � p o q o u w y nu p q p o � y w u t � r p q � � y r w � � u y n o x u � p o u w y n � p � y o w x � p u t u p q u o u w y n � r p q � � y r w � � u y n o x u � p o u w y n � p � y o w x � p u t u p q u p o u w y n� r p q � � y r w � s n � � n � � o � y n o w y n o x o y u t t � � � r � o w � p � r v y n o � u � t o � � � � t � � p � y n o � p � y u t t u y � r p r w u � o � u w u y o � r p q � � y r w �NOTE 3: � n o � p y o � w � y � r v y n o ¤ ~ å � r p q � � y r w � � r v � u w u x r � p y � x � r w y u p � o � s � y n u p r � o p � � w � � � y � p y n o ¤ ~ å � r p q � � y r w �q u p � o w r � � � r t y u � o � � u p u � � o u w u y y n o � r p � � x o w ² � o u w y n y o w x � p u t �NOTE 4: For

v � w y n o w � p v r w x u y � r p r p y n o � å ¡ } ¡ � o u w y n � p � � � � y o x w o v o w y r � { å � ¢ ­ � £ � �

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �13 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

4.3.2 Service connections ? B F ] D W B W E C C B W U D E C [ [ H I d d W E J \ d Z Q D U H U H B K E d d E Q D C G OI N E \ B C Q D F B [ B F ] D W B W E C C B W U D E C [ [ H I d d C E U _ B V [ B R ³_ N W E C W B C U F D W W I _ d B W E J \ F D [ D C G I \ H I [ B W E C R V W U E F k [ I C R U H B 1 4 = W E C R V W U E F [ H I d d _ B V [ B R K E FE ] B F H B I R d D C B [ B F ] D W B W E C C B W U D E C [ ³_ N U H B I F J E V F B R 3 : W I _ d B [ H I d d _ B V [ B R K E F 3 : V C R B F G F E V C R [ B F ] D W B W E C C B W U D E C [ ³W N D C I [ D C G d B i \ H I [ B [ B F ] D W B W E C C B W U D E C U H B W F E [ [ [ B W U D E C I d I F B I E K U H B 1 4 = W E C R V W U E F [ H I d d _ B I Ud B I [ U U H B [ I J B I [ U H B \ H I [ B W E C R V W U E F S 2 C U H B U H F B B i \ H I [ B W E C C B W U D E C U H B 1 4 = W E C R V W U E F [ H I d dC E U _ B d B [ [ U H I C H I d K U H B W F E [ [ [ B W U D E C I d I F B I E K U H B \ H I [ B W E C R V W U E F ³ I C RR N U H B W V [ U E J B F � [ B I F U H D C G U B F J D C I d I U U H B \ E D C U E K [ V \ \ d Z [ H I d d _ B W E C C B W U B R U E U H B 1 4 = W E C R V W U E FE C U H B [ V \ \ d Z [ D R B E K U H B W D F W V D U i _ F B I � B F SK N = E B I F U H B d B W U F E R B [ H I d d _ B D C [ U I d d B R I U U H B W V [ U E J B F æ [ \ F B J D [ B [ S 8 W W E F R D C G U E ? 8 = ? a f T h T L [ B B; D G V F B T _ B d E Q N � I _ F B I � D C U H B C B V U F I d E K I C B K K B W U D ] B W E J _ D C I U D E C E K I > > I C R > = . ? [ Z [ U B J [W I C H I ] B [ B ] B F B W E C [ B c V B C W B [ K E F U H B W V [ U E J B F Q H E H I [ I [ B \ I F I U B W V [ U E J B F � [ B I F U H S> H B F B K E F B D C E F R B F U E J D U D G I U B U H D [ � E \ U D E C ^ S X S a J N I _ E ] B [ H I d d _ B W E C [ D R B F B R Q H B F B I \ \ F E \ F D I U B SL ; E F B M I J \ d B D K I [ D C G d B \ H I [ B 3 : C B U Q E F � d E I R E K T � � F B [ D [ U D ] B d E I R I C R I U F I C [ K E F J B F B I F U HF B [ D [ U I C W B E K g f E H J [ � U H B W V [ U E J B F B I F U H Q E V d R H I ] B U E _ B _ B d E Q a ` E H J [ U E B C [ V F B I [ I K BU E V W H \ E U B C U D I d E K X T : E d U [ S N

Figure 2 – TT System earthing with a TN-C-S earthing system extension.

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �14 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

4.4 Earthing of MV overhead lines ? U B B d Q E F � B J \ d E Z B R E C J B R D V J ] E d U I G B Q E E R \ E d B [ U F V W U V F B [ D [ G B C B F I d d Z C E U B I F U H B R B M W B \ U Q H B F BB c V D \ J B C U � K E F B M I J \ d B � U F I C [ K E F J B F [ � \ E d B i J E V C U B R I V U E i F B W d E [ B F [ ³ B U W S � D [ D C [ U I d d B R S � H B F B U H B B I F U H D C G E K Q E E R \ E d B [ D [ F B c V D F B R D C E F R B F U E I U U I D C U H B F B c V D F B R 6 2 3 � I G I d ] I C D � B R [ U B B d Q D F B J I Z_ B V [ B R I [ U H B R E Q C d B I R S . E \ \ B F R E Q C d B I R [ [ H I d d _ B V [ B R Q H B F B B c V D \ J B C U L D S B S [ V F G B I F F B [ U B F N B I F U H [I F B F B c V D F B R S 2 C I F B I [ \ F E C B U E W E \ \ B F U H B K U � I W E C R V W U E F E K I C B c V D ] I d B C U J I U B F D I d J I Z _ B V [ B R S

4.5 Earthing of cables > H B I F J E V F D C G I C R J B U I d [ H B I U H E K W I _ d B [ [ H I d d _ B _ E C R B R U E B I F U H I U _ E U H B C R [ E K U H B W I _ d B S 6 E C R D C G U EU H B W I _ d B I F J E V F D C G I C R k E F J B U I d [ H B I U H [ H I d d _ B \ B F K E F J B R _ Z J B I C [ E K I C I \ \ F E ] B R I C R U Z \ B i U B [ U B R �[ E d R B F i d B [ [ J B W H I C D W I d W E C C B W U D E C B S G S W E C [ U I C U K E F W B [ \ F D C G [ E F Q E F J R F D ] B W d I J \ [ � V [ D C G U D C C B R W E \ \ B FB I F U H W E C R V W U E F _ F I D R [ E K C E U d B [ [ U H I C a b J J ± V C d B [ [ d E W I d B I F U H K I V d U W V F F B C U d B ] B d [ � V [ U D K Z I C D C W F B I [ B D CW F E [ [ i [ B W U D E C E F V C d B [ [ E U H B F Q D [ B [ \ B W D K D B R S. E C U D C V D U Z E K U H B W I _ d B I F J E V F D C G I C R J B U I d [ H B I U H [ H I d d _ B J I D C U I D C B R I U I d d W I _ d B � E D C U [ S ; E F K V F U H B F R B U I D d [E C U H B B I F U H D C G E K W I _ d B [ F B K B F U E 5 > ? A X ^ i a a g ` � 5 D [ U F D _ V U D E C ? U I C R I F R � 1 I F U T T � ? B W U D E C f O l B C B F I d2 C K E F J I U D E C I C R F B c V D F B J B C U [ K E F J B R D V J i ] E d U I G B W I _ d B [ Z [ U B J [ S4.6 Earth electrodes

4.6.1 Standard earth electrode configurations 4 I F U H B d B W U F E R B [ I F B W E C [ U F V W U B R K F E J _ V F D B R H E F D � E C U I d W E C R V W U E F [ E F ] B F U D W I d d Z R F D ] B C F E R [ E F IW E J _ D C I U D E C E K U H B [ B S 2 C [ E J B I \ \ d D W I U D E C [ I W E C R V W U E F J I Z _ B D C [ U I d d B R ] B F U D W I d d Z D C I _ E F B R H E d B S6 V F D B R H E F D � E C U I d W E C R V W U E F [ L U B F J B R U F B C W H B d B W U F E R B [ N I F B B I [ D B F U E D C [ U I d d U H I C ] B F U D W I d F E R [ S 8 K V F U H B FI R ] I C U I G B D [ U H I U \ E U B C U D I d G F I R D B C U [ I U U H B [ E D d [ V F K I W B Q H D W H F B [ V d U K F E J W V F F B C U R D [ W H I F G B _ Z I U F B C W HB d B W U F E R B I F B d B [ [ [ U B B \ U H I C D [ U H B W I [ B K E F ] B F U D W I d d Z D C [ U I d d B R W E C R V W U E F [ S 2 K U H B G F E V C R D [ ] B F Z R D K K D W V d U U ER D G L D K D U D [ F E W � N � U H B C I ] B F U D W I d B I F U H B d B W U F E R B [ H E V d R _ B D C [ U I d d B R D C I R F D d d B R H E d B S: B F U D W I d d Z D C [ U I d d B R B d B W U F E R B [ J I Z _ B B M U B C R B R U E [ V _ [ U I C U D I d d B C G U H [ I C R I F B E K U B C I _ d B U E J I � B W E C U I W UQ D U H ] B F Z d E Q F B [ D [ U D ] D U Z [ E D d [ K I F _ B d E Q U H B B I F U H � [ [ V F K I W B S > H B F B [ D [ U D ] D U Z E K U H B [ E D d K V F U H B F _ B d E Q U H B[ V F K I W B D [ d B [ [ \ F E C B U E [ B I [ E C I d K d V W U V I U D E C I C R U H B F B [ D [ U I C W B E K ] B F U D W I d F E R [ D [ U H V [ ] B F Z [ U I _ d B S4 I F U H B d B W U F E R B [ B M H D _ D U R D K K B F B C U D J \ B R I C W B W H I F I W U B F D [ U D W [ K E F W V F F B C U E K R D K K B F B C U J I G C D U V R B [ I C RK F B c V B C W D B [ S > F B C W H B d B W U F E R B [ I F B � C E Q C U E E K K B F d E Q B F D J \ B R I C W B I U \ E Q B F K F B c V B C W Z U H I C R E B c V D ] I d B C U] B F U D W I d W E C R V W U E F [ S : B F U D W I d F E R [ E K K B F [ V \ B F D E F \ B F K E F J I C W B V C R B F [ V F G B W E C R D U D E C [ S4 d B W U F E R B [ W E C [ U F V W U B R K F E J I W E J _ D C I U D E C E K R F D ] B C F E R [ I C R F I R D I d I F F I Z [ E K _ V F D B R W E C R V W U E F [ I F BD C [ U I d d B R D C E F R B F U E B C [ V F B I [ U I _ d B F B [ D [ U I C W B ] I d V B I C R U E J D C D J D � B U H B H I � I F R E K H D G H [ V F K I W B \ E U B C U D I d [R V F D C G U D J B [ E K W V F F B C U R D [ W H I F G B S . E J _ D C B R B d B W U F E R B [ I d [ E [ I U D [ K Z U H B E _ � B W U D ] B E K H I ] D C G _ E U H [ V F G BD J \ B R I C W B [ I C R ` f @ � D J \ B R I C W B [ I [ d E Q I [ \ E [ [ D _ d B S . E J _ D C I U D E C I d [ E K I W D d D U I U B [ W V F F B C U R D ] D [ D E C I [ Q B d dI [ E K K B F D C G J V d U D \ d B D C R B \ B C R B C U \ I U H [ U E F B R V W B U H B B K K B W U E K I \ E [ [ D _ d B B I F U H D C G W E C R V W U E F K I D d V F B S4 I F U H B d B W U F E R B [ [ H I d d _ B D C [ U I d d B R I [ R B B \ I [ \ E [ [ D _ d B I C R C E U d B [ [ U H I C ` f f J J _ B d E Q U H B G F E V C R[ V F K I W B S > H B F B I [ E C K E F U H D [ [ \ B W D K D W I U D E C D [ U H I U U H B d I Z B F E K [ E D d I _ E ] B U H B W E C R V W U E F K E F J [ I C D J \ E F U I C UJ B R D V J D C U E Q H D W H U H B B d B W U F E R B W I C R D [ [ D \ I U B W V F F B C U S 5 B B \ _ V F D B R B d B W U F E R B [ I d [ E B M H D _ D U d B [ [ [ U B B \] E d U I G B G F I R D B C U [ I U U H B [ E D d [ V F K I W B R V F D C G U D J B [ E K W V F F B C U R D [ W H I F G B S ; V F U H B F � R B B \ _ V F D I d F B R V W B [ U H B\ E [ [ D _ D d D U Z E K J B W H I C D W I d R I J I G B E K U H B B I F U H B d B W U F E R B S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �15 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

> H B K E V F [ U I C R I F R B d B W U F E R B U Z \ B [ I F B D R B C U D K D B R K E F I \ \ d D W I U D E C OI N = E C i B M U B C R I _ d B B I F U H F E R [ V [ B R K E F I J V d U D i F E R B d B W U F E R B W E C K D G V F I U D E CNOTE A

y n w o o � r � p y � y u w o t o � y w r q o � � y n o � w o v o w w o q � r p v � � � w u y � r p � { p u t y o w p u y � � o � r p v � � � w u y � r p � � u t � p o u w y w o p � n o t o � y w r q o s � y np r p ¡ o ¾ y o p q u � t o o u w y n w r q � ç s n � � n � � � w u � y � � u t t � x r w o � � � y u � t o v r w � p q o w � w r � p q � u � t o p o y s r w § � p � y u t t u y � r p � �_ N 3 D C B I F U F B C W H B d B W U F E R B8 d D C B I F U F B C W H B d B W U F E R B D [ I H E F D � E C U I d d Z I \ \ d D B R B d B W U F E R B I C R J I Z _ B D C [ U I d d B R Q H B F B D U D [ C E U\ E [ [ D _ d B U E D C [ U I d d ] B F U D W I d F E R [ SW N 4 M U B C R I _ d B B I F U H F E R [> H B V [ B E K B M U B C R I _ d B B I F U H F E R [ D [ E \ U D E C I d ³ K E F B M I J \ d B � U H B Z J I Z _ B V [ B R Q H B C I ] B F U D W I d B I F U HB d B W U F E R B D C [ U I d d I U D E C D [ F B c V D F B R SR N : B F U D W I d d Z D C [ U I d d B R W E C R V W U E F> H B D C [ U I d d I U D E C E K I ] B F U D W I d B I F U H W E C R V W U E F D [ I \ \ F E \ F D I U B D K U H B F B I F B [ \ I W B W E C [ U F I D C U [ U H I U J I � B U H BD C [ U I d d I U D E C E K I U F B C W H B d B W U F E R B D J \ E [ [ D _ d B E F Q H B C U H B [ E D d I U U H B [ D U B H I [ _ B B C D R B C U D K D B R I [ I U Q E i d I Z B F[ E D d Q D U H U H B U E \ d I Z B F H I ] D C G I H D G H B F F B [ D [ U D ] D U Z U H I C U H B d E Q B F d I Z B F S 2 U D [ I d [ E I \ \ F E \ F D I U B Q H B C U H B G F E V C RD [ B M U F B J B d Z H I F R U E R D G L D K D U D [ F E W � N I C R U H B B d B W U F E R B D [ U E _ B D C [ U I d d B R D C I R F D d d B R H E d B S� H B C U H B [ E D d D [ I U Q E i d I Z B F [ E D d Q D U H U H B U E \ d I Z B F H I ] D C G I H D G H B F F B [ D [ U D ] D U Z U H I U U H B d E Q B F d I Z B F ³ U H B ] B F U D W I dB d B W U F E R B D [ V [ B R U E F B I W H U H B J E F B W E C R V W U D ] B d E Q B F d I Z B F S ; E F U H D [ W I [ B � U H B R B \ U H E K U H B V \ \ B F [ E D d d I Z B F[ H E V d R _ B I R R B R U E U H B d B C G U H E K U H B ] B F U D W I d W E C R V W U E F F B c V D F B R � I [ F B I R K F E J > I _ d B X I S > H D [ D [ _ B W I V [ BE C d Z U H B \ E F U D E C E K U H B ] B F U D W I d B d B W U F E R B D C U H B d E Q F B [ D [ U D ] D U Z d I Z B F H I [ I C Z B K K B W U E C U H B B d B W U F E R BF B [ D [ U I C W B S � H B C U H D [ D [ R E C B � U H B F B [ D [ U D ] D U Z E K U H B [ E D d V [ B R U E R B U B F J D C B U H B d B C G U H E K W E C R V W U E F F B c V D F BW I C _ B U I � B C I [ U H B F B [ D [ U D ] D U Z E K U H B d E Q B F [ E D d d I Z B F S> H B R B \ U H E K U H B U E \ d I Z B F E K [ E D d W I C _ B R B U B F J D C B R _ Z K D U U D C G I U Q E d I Z B F [ E D d J E R B d U E U H B J B I [ V F B R R I U I S> H B \ F E W B [ [ D [ E V U d D C B R D C ? . ? 8 ? 8 6 Y X L l B C B F D W [ V _ [ U I U D E C R B [ D G C N � W d I V [ B ^ S a S e S T S> H B R D J B C [ D E C [ E K [ U I C R I F R J I D C B I F U H B d B W U F E R B [ K E F F B c V D F B R F B [ D [ U I C W B [ E K X f � g f I C Ra ` f I F B \ F E ] D R B R D C U I _ d B [ X � ^ I C R ` F B [ \ B W U D ] B d Z S > H B [ B I F B U H B \ F B K B F F B R W E C K D G V F I U D E C [ K E F B I F U H D C G I UB c V D \ J B C U D C [ U I d d I U D E C [ S � H B F B U H B [ U I C R I F R B I F U H B d B W U F E R B U Z \ B [ W I C C E U _ B D C [ U I d d B R U H B I \ \ F E \ F D I U BI d U B F C I U D ] B [ D C U I _ d B [ X I E F ^ I [ H I d d _ B W E C [ D R B F B R S> H B B d B W U F E R B R D J B C [ D E C [ [ \ B W D K D B R D C U H B K E d d E Q D C G U I _ d B [ Q B F B R B F D ] B R V [ D C G U H B W I d W V d I U D E C \ F E W B R V F B I [R B [ W F D _ B R D C ? 8 = ? a f a h h I C R 5 9 1 A X ^ i a h X X 9 B \ E F U O / \ U D J D � I U D E C E K 0 : B I F U H B d B W U F E R B R B [ D G C STable 3 – Standard earth electrode configurations for 30 resistance

Description Main earth electrode è é ê ë � � ì ë í î � ¼ » º ½è é ê ë � � ì ê � � ï � ð � ñ ë � � � ò ó � î � � � ë � ë ñ �µ î î é � ê ñ ô é � � � é � � � � ë � � � ë íñ ë ñ ì î ë ó � ï � õ º ö ë � õ º ö ´ � � ö ¶ ÷ ¼ � � ÷ ½ � � ÷ ø � � ÷ º � �è é ê ë � � ì ì � ö � � � � � � ´ ö ¶ ù î ë � � � ù î ë � � � � ù î ë � � � ù î ë � � � �ú ò � � ê ó ì î ë ó´ ö � � � ö ö ¶ � õ º � õ º � õ º � õ º � õ º � õ ºú � ñ ì � ñ é é � ð ë ó ´ û ¶ º õ � ¼ õ � � � õ � � ¼ õ � » � õ � » õ �ú � � ì é � ð ë ó õ º õ º õ º õ º õ º õ ºú � � ì � î ñ � ñ ë � � �ì � � ë ñ � ê º õ � ½ õ º õ � ü � µ � � õ � ü � µ

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �16 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

ü ö ô � � ï � � ì � » ¹ ¹ ¹ ý � ñ ð � ñ ö ö ñ ë � ê� î � � � ë ñ ë � � �þ ñ � ì í ë í î � � � é ÿ � ñ � éë í î � � � é þ ñ � ì í ë í î � � � é ÿ � ñ � éë í î � � � é

NOTE:~ u � n x u � p o u w y n o t o � y w r q o y � � o � � q o � � � p o q v r w y n o � p q � � u y o q � r � t w o � � � y � � � y � � u t � o � m n o w o � p y o w x o q � u y ow o � � � y � � � y � � u t � o � u w o o p � r � p y o w o q � u p o t o � y w r q o q o � � � p o q v r w y n o p o ¾ y n � � n o w w o � � � y � � � y � � u t � o � n u t t � o � p � y u t t o q �

Table 3a – Alternative earth electrode configurations for 30 resistance

Description Main earth electrode è é ê ë � � ì ë í î � ¼ »è é ê ë � � ì ê � � ï � ð � ñ ë � � � � � ð ó ë ñ � ð é ë � � � � � � � é � � µ î î é � ê ñ ô é � � � é � � � � ë � � � ë í ñ ë ñì î ë ó � ï � õ º ö ë � õ º ö´ � � ö ¶ ÷ ¼ � � ÷ ½ � � ÷ ø � � ÷ º � �Alternative 1 Electrode with earth spikes è é ê ë � � ì ì � ö � � � � � � ´ ö ¶ú ò � � ê ó ì î ë ó ´ ö � � � ö ö ¶ � õ º � õ º � õ º � õ ºú � ñ ì � ñ é é � ð ë ó ´ û ¶ � õ � � � õ � ¼ � õ � º � õ �ú � � ì é � ð ë ó õ º õ º õ º õ ºú � � ì � î ñ � ñ ë � � � ì � � ë ñ � ê � õ � � � õ � ¼ � õ � º � õ �ü ö ô � � ï � � ì � ¼ ¼ ¼ ¼ý � ñ ð � ñ ö ö ñ ë � ê � î � � � ë ñ ë � � �

Alternative 2 Electrode without earth spikes è é ê ë � � ì ì � ö � � � � � � ´ ö ¶ú ò � � ê ó ì î ë ó ´ ö � � � ö ö ¶ � õ º � õ º � õ º � õ ºú � ñ ì � ñ é é � ð ë ó ´ û ¶ ø õ � » õ � ½ º õ � � � õ �ü ö ô � � ï � � ì � � � � �

ûûû ûûû ûûû ûûû ûûûûûû

ûûûûûû ûûû û û û û û û û

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �17 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

ý � ñ ð � ñ ö ö ñ ë � ê � î � � � ë ñ ë � � �NOTE 1: � n o o u w y n t o u q v w r x y n o o � � � � x o p y � n r � t q � w o v o w u � t � � o � r p p o � y o q y r y n o � o p y w o r v y n o o t o � y w r q o y r� w r � � q o y n o � o � y � � w w o p y q � � y w � � � y � r p � p y n o o t o � y w r q o � p q o w v u � t y u p q t � � n y p � p � q � � � n u w � o � r p q � y � r p � �NOTE 2: � n o � � w � o q n r w � � r p y u t o t o � y w r q o � p u t y o w p u y � � o � � � � � � y u � t o v r w u w o u � s n o w o � y � � q � v v � � � t y y r � p � y u t t o u w y nw r q � �

Table 3a (concluded) – Alternative earth electrode configurations for 30 resistance

Description Main earth electrode è é ê ë � � ì ë í î � ¼ »è é ê ë � � ì ê � � ï � ð � ñ ë � � � ý � � é é ì � ó � é � � ë � ê ñ é ê � � ì ê ë � �µ î î é � ê ñ ô é � � � é � � � � ë � � � ë í ñ ë ñì î ë ó � ï � õ º ö ë � õ º ö´ � � ö ¶ ÷ ¼ � � ÷ ½ � � ÷ ø � � ÷ º � �è é ê ë � � ì ì � ö � � � � � � ´ ö ¶ú ò � � ê ó ì î ë ó ´ ö � � � ö ö ¶ � õ º � õ º � õ º � õ ºú ¸ � ë � ê ñ é ê � � ì ê ë � � é � ð ë ó º õ � ¼ ¼ õ � º � õ � ø � õ �ü ö ô � � ï � � ì � NOTE 1: � w � t t o q ¡ n r t o � o w y � � u t � r p q � � y r w o t o � y w r q o � u w o � � � y u � t o � p u w o u � s n o w o � � u � o w o � y w � � y � r p � x u § o � y q � v v � � � t y y r� p � y u t t n r w � � r p y u t o t o � y w r q o � �NOTE 2: � n o � u t � o � � � � o p u w o v r w u � u w o ¢ � x x � � r � � o w � r p q � � y r w t u � q � o w y � � u t t � � p u q w � t t o q ¡ n r t o �

Table 4 – Standard earth electrode configurations for 70 resistance

Description Main earth electrode è é ê ë � � ì ë í î � ¼ »è é ê ë � � ì ê � � ï � ð � ñ ë � � � ò ó � î � � � ë � ë ñ �µ î î é � ê ñ ô é � � � é � � � � ë � � � ë í ñ ë ñì î ë ó � ï � õ º ö ë � õ º ö´ � � ö ¶ ÷ ¼ � � ÷ ½ � � ÷ ø � � ÷ º � �è é ê ë � � ì ì � ö � � � � � � ´ ö ¶ú ò � � ê ó ì î ë ó ´ ö � � � ö ö ¶ � õ º � õ º � õ º � õ ºú � ñ ì � ñ é é � ð ë ó ´ û ¶ � õ � » õ � � õ � º õ �ú � � ì é � ð ë ó õ º õ º õ º õ ºú � � ì � î ñ � ñ ë � � � ì � � ë ñ � ê ü � µ » õ � ø õ � º õ �ü ö ô � � ï � � ì � » » » »ý � ñ ð � ñ ö ö ñ ë � ê � î � � � ë ñ ë � � �NOTE:

~ u � n x u � p o u w y n o t o � y w r q o y � � o � � q o � � � p o q v r w y n o � p q � � u y o q � r � t w o � � � y � � � y � � u t � o � m n o w o � p y o w x o q � u y ow o � � � y � � � y � � u t � o � u w o o p � r � p y o w o q � u p o t o � y w r q o q o � � � p o q v r w y n o p o ¾ y n � � n o w � � � o p w o � � � y � � � y � � u t � o � n u t t � o� p � y u t t o q �

ûûûû

ûûûûûû ûûû ûûû

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �18 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Table 4a – Alternative earth electrode configurations for 70 resistance

Description Main earth electrode è é ê ë � � ì ë í î � ¼ »è é ê ë � � ì ê � � ï � ð � ñ ë � � � � � ð ó ë ñ � ð é ë � � � � � � � é � � µ î î é � ê ñ ô é � � � é � � � � ë � � � ë í ñ ë ñì î ë ó � ï � õ º ö ë � õ º ö´ � � ö ¶ ÷ ¼ � � ÷ ½ � � ÷ ø � � ÷ º � �Alternative 1 Electrode with earth spikes è é ê ë � � ì ì � ö � � � � � � ´ ö ¶ú ò � � ê ó ì î ë ó ´ ö � � � ö ö ¶ � õ º � õ º � õ º � õ ºú � ñ ì � ñ é é � ð ë ó ´ û ¶ ¼ õ � ½ õ º � õ � � � õ �ú � � ì é � ð ë ó õ º õ º õ º õ ºú � � ì � î ñ � ñ ë � � � ì � � ë ñ � ê ü � µ ½ õ º � õ � � � õ �ü ö ô � � ï � � ì � ¼ ¼ ¼ý � ñ ð � ñ ö ö ñ ë � ê � î � � � ë ñ ë � � �

Alternative 2 Electrode without earth spikes è é ê ë � � ì ì � ö � � � � � � ´ ö ¶ú ò � � ê ó ì î ë ó ´ ö � � � ö ö ¶ � õ º � õ º � õ º � õ ºú � ñ ì � ñ é é � ð ë ó ´ û ¶ ¹ õ � ½ õ � � ½ õ � » ½ õ �ü ö ô � � ï � � ì � � � � �ý � ñ ð � ñ ö ö ñ ë � ê � î � � � ë ñ ë � � �NOTE 1

¥ � n o o u w y n t o u q v w r x y n o o � � � � x o p y � n r � t q � w o v o w u � t � � o � r p p o � y o q y r y n o � o p y w o r v y n o o t o � y w r q o y r� w r � � q o y n o � o � y � � w w o p y q � � y w � � � y � r p � p y n o o t o � y w r q o � p q o w v u � t y u p q t � � n y p � p � q � � � n u w � o � r p q � y � r p � �NOTE 2

¥ � n o � � w � o q n r w � � r p y u t o t o � y w r q o � p u t y o w p u y � � o � � � � � � y u � t o v r w u w o u � s n o w o � y � � q � v v � � � t y y r � p � y u t t o u w y nw r q � �ûû

ûûûûûû ûûû û û û û û û ûûû

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �19 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Table 5 – Standard earth electrode configurations for 150 resistance

Description Main earth electrode è é ê ë � � ì ë í î � ¼ »è é ê ë � � ì ê � � ï � ð � ñ ë � � � ò ó � î � � � ë � ë ñ �µ î î é � ê ñ ô é � � � é � � � � ë � � � ë í ñ ë ñì î ë ó � ï � õ º ö ë � õ º ö´ � � ö ¶ ÷ ¼ � � ÷ ½ � � ÷ ø � � ÷ º � �è é ê ë � � ì ì � ö � � � � � � ´ ö ¶ú ò � � ê ó ì î ë ó ´ ö � � � ö ö ¶ � õ º � õ º � õ º � õ ºú � ñ ì � ñ é é � ð ë ó ´ û ¶ õ � � õ � ¼ õ º ½ õ ºú � � ì é � ð ë ó õ º õ º õ º õ ºú � � ì � î ñ � ñ ë � � � ì � � ë ñ � ê ü � µ ü � µ ü � µ ü � µü ö ô � � ï � � ì � ý � ñ ð � ñ ö ö ñ ë � ê � î � � � ë ñ ë � � �NOTE:

~ u � n x u � p o u w y n o t o � y w r q o y � � o � � q o � � � p o q v r w y n o � p q � � u y o q � r � t w o � � � y � � � y � � u t � o � m n o w o � p y o w x o q � u y ow o � � � y � � � y � � u t � o � u w o o p � r � p y o w o q � u p o t o � y w r q o q o � � � p o q v r w y n o p o ¾ y n � � n o w � � � o p w o � � � y � � � y � � u t � o � n u t t � o� p � y u t t o q �4.6.2 Earth electrode enhancement 0 B U H E R [ E K B d B W U F E R B B C H I C W B J B C U L R B [ W F D _ B R D C I C C B M 6 N D C W d V R B U H B B C W I [ B J B C U E K U H B B d B W U F E R B D CW E C R V W U D ] B W E C W F B U B I C R U H B W H B J D W I d U F B I U J B C U E K U H B [ E D d [ V F F E V C R D C G U H B B d B W U F E R B S > H B [ B J B U H E R [ J I Z_ B W E C [ D R B F B R D C W B F U I D C W D F W V J [ U I C W B [ I [ I \ E [ [ D _ d B [ E d V U D E C U E U H B \ F E _ d B J E K H D G H B d B W U F E R B F B [ D [ U I C W B U EB I F U H S > H B Z J I Z I d [ E _ B I \ \ d D B R D C I F B I [ Q H B F B I W E C [ D R B F I _ d B ] I F D I U D E C E K B d B W U F E R B F B [ D [ U I C W B D [B M \ B F D B C W B R R V B U E [ B I [ E C I d W d D J I U D W W H I C G B [ S4 C W I [ D C G B I F U H B d B W U F E R B [ D C W E C R V W U D ] B W E C W F B U B D [ I W E [ U d Z J B I C [ E K F B R V W D C G U H B B d B W U F E R B F B [ D [ U I C W B U EU F V B B I F U H S > H B \ F I W U D W B J I Z � H E Q B ] B F � K D C R I \ \ d D W I U D E C Q H B F B [ \ I W B d D J D U I U D E C [ D C H D _ D U U H B V [ B E K B M \ I C [ D ] BB d B W U F E R B R B [ D G C [ S 4 C W I [ D C G B d B W U F E R B [ D C W E C W F B U B H I [ U H B I R R B R _ B C B K D U E K D J \ F E ] B R F B [ D [ U I C W B U E U H B K U S; V d d R B U I D d [ F B G I F R D C G U H B I \ \ d D W I U D E C E K W E C R V W U D ] B W E C W F B U B I F B \ F B [ B C U B R D C I C C B M 6 S a S> H B E \ U D E C E K W H B J D W I d U F B I U J B C U E K U H B [ E D d D [ U E _ B I \ \ d D B R _ Z B M W B \ U D E C U E I ] E D R I C V C C B W B [ [ I F Z _ V F R B C_ B D C G \ d I W B R E C E \ B F I U D C G I C R J I D C U B C I C W B [ U I K K K E F K E d d E Q i V \ U F B I U J B C U I \ \ d D W I U D E C [ S 5 B U I D d [ F B G I F R D C G U H BI \ \ d D W I U D E C E K W H B J D W I d U F B I U J B C U I F B G D ] B C D C I C C B M 6 S T S4.6.3 Earth electrode selection and installation procedure > H B K E d d E Q D C G \ F E W B R V F B [ H I d d _ B K E d d E Q B R Q H B C B [ U I _ d D [ H D C G I J I D C B I F U H B d B W U F E R B D C [ U I d d I U D E C OI N I [ E D d F B [ D [ U D ] D U Z [ V F ] B Z [ H I d d _ B V C R B F U I � B C U E B [ U I _ d D [ H [ V D U I _ d B B d B W U F E R B [ D U B [ ³_ N I C B d B W U F E R B U Z \ B I \ \ F E \ F D I U B K E F U H B [ E D d W E C R D U D E C [ [ H I d d _ B [ B d B W U B R ³ I C RW N U H B B d B W U F E R B [ H I d d _ B D C [ U I d d B R S 2 K U H B D C [ U I d d B R B d B W U F E R B D [ C E C i [ U I C R I F R � D U [ D J \ B R I C W B [ H I d d _ BJ B I [ V F B R S ? U I C R I F R B d B W U F E R B [ I F B R B [ W F D _ B R D C [ B W U D E C ^ S b S a I C R I C C B M 6 S a SR N K E F J D C E F Q E F � [ E C d Z � U H B \ F E W B [ [ J I Z [ U I F U K F E J _ N I C R U H B D J \ B R I C W B E K D C [ U I d d B R B d B W U F E R B [ H I d d_ B J B I [ V F B R S

ûûû ûûû ûûû ûûû

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �20 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

4.6.3.1 Soil resistivity survey > H B F B [ D [ U I C W B U E B I F U H E K I C B d B W U F E R B D [ D C K d V B C W B R _ Z U H B F B [ D [ U D ] D U Z E K U H B [ V F F E V C R D C G [ E D d S > H BJ B I [ V F B J B C U E K [ E D d F B [ D [ U D ] D U Z D [ U H B F B K E F B I C B M U F B J B d Z D J \ E F U I C U K V C W U D E C I C R [ H I d d K E F J I C D C U B G F I d \ I F U E KU H B E ] B F I d d B I F U H D C G \ F E W B [ [ S 8 [ E D d F B [ D [ U D ] D U Z [ V F ] B Z [ H I d d _ B D J \ d B J B C U B R I [ K E d d E Q [ OI N 9 V F I d U F I C [ K E F J B F [; E F I [ D C G d B U F I C [ K E F J B F D C [ U I d d I U D E C � B S G S I F V F I d \ E D C U E K [ V \ \ d Z � I [ E D d F B [ D [ U D ] D U Z [ V F ] B Z D [ F B c V D F B RU E B [ U I _ d D [ H U H B d E W I U D E C _ B [ U [ V D U B R I C R J E [ U \ F I W U D W I d d Z K B I [ D _ d B K E F U H B U F I C [ K E F J B F D C [ U I d d I U D E C S> H B F B [ V d U [ I F B I d [ E V [ B R U E [ B d B W U I C B I F U H B d B W U F E R B [ V D U I _ d B K E F U H E [ B [ \ B W D K D W [ E D d W E C R D U D E C [ S> H B \ F E W B R V F B U E [ B d B W U I [ V D U I _ d B B d B W U F E R B D [ R B [ W F D _ B R I _ E ] B [ H I d d _ B K E d d E Q B R S_ N < F _ I C U F I C [ K E F J B F [> E B [ U I _ d D [ H I C B U Q E F � E K U F I C [ K E F J B F D C [ U I d d I U D E C [ � B S G S I U E Q C [ H D \ B d B W U F D K D W I U D E C \ F E � B W U � I[ B \ I F I U B [ E D d F B [ D [ U D ] D U Z [ V F ] B Z [ H I d d _ B W E C R V W U B R I U B I W H \ F E \ E [ B R d E W I U D E C K E F I U F I C [ K E F J B FD C [ U I d d I U D E C S > H B [ B F B [ V d U [ I F B V [ B R U E [ B d B W U K E F B I W H U F I C [ K E F J B F I C B I F U H B d B W U F E R B U H I U D [[ V D U I _ d B K E F U H B [ \ B W D K D W [ E D d W E C R D U D E C [ I U U H B B c V D \ J B C U d E W I U D E C S> H B [ E D d F B [ D [ U D ] D U Z [ V F ] B Z [ H I d d _ B \ B F K E F J B R V [ D C G U H B � B C C B F J B U H E R I [ R B [ W F D _ B R D C ` S X S> H B [ E D d F B [ D [ U D ] D U Z ] I d V B L N J B I [ V F B R D C E H J J B U F B [ L J N I U I R B \ U H E K f � ` J U E a � ` J _ B d E QG F E V C R d B ] B d D [ V [ B R K E F U H B [ B d B W U D E C E K I C I \ \ F E \ F D I U B B I F U H B d B W U F E R B S > H D [ R B \ U H F I C G B D [D J \ E F U I C U I [ U H B [ E D d U H I U D [ W d E [ B U E U H B B d B W U F E R B H I [ U H B G F B I U B [ U \ E [ D U D ] B B K K B W U E C D U [ K D C I dF B [ D [ U I C W B ] I d V B S2 R B C U D K D W I U D E C E K U H B U Z \ B E K [ E D d U H I U D [ B C W E V C U B F B R W I C G D ] B I F E V G H D C R D W I U D E C I [ U E U H B B M \ B W U B R[ E D d F B [ D [ U D ] D U Z S 8 C C B M 8 D C W d V R B [ D C K E F J I U D E C F B G I F R D C G [ E D d D R B C U D K D W I U D E C I C R U H B B M \ B W U B RF B [ D [ U D ] D U Z F I C G B [ E K R D K K B F B C U U Z \ B [ E K [ E D d S4.6.3.2 Earth electrode selection 8 [ U I C R I F R B I F U H B d B W U F E R B U Z \ B D [ [ B d B W U B R K F E J U I _ d B X � X I � ^ � ^ I E F ` E C U H B _ I [ D [ E K U H B F B c V D F B RF B [ D [ U I C W B ] I d V B I C R U H B F B [ V d U E K U H B I \ \ I F B C U [ E D d F B [ D [ U D ] D U Z J B I [ V F B J B C U L U I � B C I U f � ` J U E a � ` J _ B d E QG F E V C R d B ] B d N S 8 U H F B B \ E D C U [ U I F B d B W U F E R B W E C K D G V F I U D E C D [ \ F B K B F F B R S� H B F B U H B J B I [ V F B R F B [ D [ U D ] D U Z ] I d V B R E B [ C E U W E F F B [ \ E C R U E E C B E K U H B K E V F ¿ [ U I C R I F R À ] I d V B [ [ \ B W D K D B R D CU H B U I _ d B [ O X f f J � b f f J � h f f J I C R a ` f f J � I C B d B W U F E R B R B [ D G C B R K E F U H B C B M U H D G H B [ U [ U I C R I F RF B [ D [ U D ] D U Z ] I d V B [ H E V d R _ B [ B d B W U B R S ; E F B M I J \ d B � D K U H B [ E D d F B [ D [ U D ] D U Z [ V F ] B Z Z D B d R B R I F B [ V d U E K ^ f f J � I[ U I C R I F R B d B W U F E R B R B [ D G C B R K E F b f f J [ H E V d R _ B [ B d B W U B R S> H B 1 F E � B W U 4 C G D C B B F D C G 5 B \ I F U J B C U [ H I d d _ B W E C [ V d U B R D C U H E [ B W I [ B [ Q H B F B D U D [ D J \ F I W U D W I d U E D C [ U I d d I C ZE K U H B J I D C E F I d U B F C I U D ] B B d B W U F E R B U Z \ B [ I C R U H B J B U H E R [ E K B d B W U F E R B B C H I C W B J B C U R B [ W F D _ B R D C I C C B M 6I F B C E U R B B J B R I \ \ F E \ F D I U B S4.6.3.3 Installation of an earth electrode 4 I F U H B d B W U F E R B W E J \ E C B C U [ I F B D C [ U I d d B R I [ K E d d E Q [ OI N @ E F D � E C U I d W E C R V W U E F [@ E F D � E C U I d W E C R V W U E F [ I F B _ V F D B R D C U F B C W H B [ C E d B [ [ U H I C ` f f J J _ B d E Q G F E V C R d B ] B d S 8 K U B FH E F D � E C U I d W E C R V W U E F [ H I ] B _ B B C D C [ U I d d B R D C U H B U F B C W H B [ � U H B U F B C W H B [ [ H I d d _ B _ I W � i K D d d B RL V [ V I d d Z V [ D C G U H B J I U B F D I d U H I U Q I [ B M W I ] I U B R K F E J U H B U F B C W H B [ N S 5 V F D C G U H B _ I W � i K D d d \ F E W B [ [ �U H B [ E D d [ H I d d _ B I R R B R D C X f f J J U H D W � d I Z B F [ I C R U H B C _ B W E J \ I W U B R _ B K E F B U H B C B M U d I Z B F [ I F BI R R B R S . I F B [ H I d d _ B U I � B C U E B C [ V F B U H I U C E [ U E C B [ I F B \ d I W B R W d E [ B U E U H B H E F D � E C U I d W E C R V W U E F �I [ U H B [ B W E V d R R I J I G B U H B W E C R V W U E F Q H B C U H B [ E D d D [ W E J \ I W U B R S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �21 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

_ N ? D C G d B B I F U H F E R [B I W H B I F U H F E R [ H I d d _ B R F D ] B C D C U E V C R D [ U V F _ B R [ E D d S > H B G B C B F I d F V d B D [ U H I U D K IK E V C R I U D E C H E d B W I C _ B B M W I ] I U B R _ Z J B W H I C D W I d J B I C [ � U H B C D U Q D d d _ B F B I [ E C I _ d Z B I [ ZU E R F D ] B D C I C B I F U H F E R �B I F U H F E R [ [ H I d d _ B R F D ] B C I J D C D J V J E K a f f f J J K F E J U H B [ U F V W U V F B I C R U H B F E R U E \ [ H I d d_ B C E U d B [ [ U H I C ` f f J J _ B d E Q G F E V C R d B ] B d �W N 4 M U B C R I _ d B B I F U H F E R [U H B W E V \ d D C G I C R R F D ] D C G _ E d U [ H I d d _ B I U U I W H B R U E U H B U E \ B C R E K U H B [ B W U D E C I d F E R �U H D [ I [ [ B J _ d Z [ H I d d _ B R F D ] B C ] B F U D W I d d Z D C U E U H B G F E V C R V [ D C G I [ \ B W D I d D J \ I W U i F B [ D [ U D C G[ U B B d R F D ] D C G \ D \ B E F J B W H I C D W I d H I J J B F V C U D d U H B W E V \ d D C G E C U H B F E R F B I W H B [ U H B G F E V C Rd B ] B d �U H B R F D ] D C G _ E d U [ H I d d _ B F B J E ] B R �U H B d E Q B F B C R E K U H B [ B W E C R F E R [ H I d d _ B K D U U B R U E U H B W E V \ d D C G �I C E U H B F W E V \ d D C G [ H I d d _ B I U U I W H B R U E U H B U E \ B C R E K U H B [ B W E C R F E R �U H B R F D ] D C G _ E d U [ H I d d _ B I U U I W H B R U E U H B [ B W E C R W E V \ d D C G �R F D ] D C G [ H I d d _ B W E C U D C V B R V C U D d U H B [ B W E C R [ B W U D E C F B I W H B [ G F E V C R d B ] B d SR N W E C C B W U D E C [ _ B U Q B B C H E F D � E C U I d W E C R V W U E F [ I C R ] B F U D W I d F E R [5 B U I D d [ F B G I F R D C G U H B D C U B F W E C C B W U D E C E K ] B F U D W I d F E R [ I C R H E F D � E C U I d W E C R V W U E F [ D C B I F U HB d B W U F E R B [ I F B \ F B [ B C U B R D C 5 i 5 > i f b ^ T S 5 i 5 > i f b ^ T I \ \ d D B [ U E W E \ \ B F W E C R V W U E F [ I C R W E \ \ B F iW d I R [ U B B d W E C R V W U E F [ S = E U D W B U H I U K E F W E \ \ B F i W d I R [ U B B d W E C R V W U E F U I D d [ J V [ U \ F E U F V R B K F E J U H BJ I D C � V C W U D E C \ E D C U W E C C B W U D E C _ Z a f f J J S� E D C U [ I C R U B F J D C I U D E C [ E K W E \ \ B F I C R W E \ \ B F i W d I R [ U B B d W E C R V W U E F [ V [ B R D C B I F U H D C G I \ \ d D W I U D E C [C B B R C E U _ B W E ] B F B R Q D U H R B C [ E U I \ B E F _ D U V J B C SB N : B F U D W I d B d B W U F E R B [2 C [ U I d d U H B ] B F U D W I d W E C R V W U E F D C U H B R F D d d B R H E d B S > H B H E d B [ H E V d R U H B C _ B _ I W � i K D d d B R Q D U H I [ d V F F ZK E F J B R _ Z J D M D C G Q I U B F Q D U H U H B B M W I ] I U B R [ E D d L I K U B F U H B B M W I ] I U B R [ E D d H I [ _ B B C [ D K U B R U EF B J E ] B I C Z d I F G B [ U E C B [ N S4.6.3.4 Measurement of the earth electrode’s resistance to earth > H B B d B W U F E R B � [ F B [ D [ U I C W B U E B I F U H C B B R E C d Z _ B J B I [ V F B R D C U H B B ] B C U U H I U I C E C i [ U I C R I F R B d B W U F E R B D [D C [ U I d d B R S � H B F B U H D [ D [ U H B W I [ B � U H B F B [ D [ U I C W B J B I [ V F B J B C U [ H I d d _ B W E C R V W U B R I [ R B [ W F D _ B R D C ` S ^ S? U I C R I F R B d B W U F E R B [ I F B R B [ W F D _ B R D C [ B W U D E C ^ S b S a I C R I C C B M 6 S a S4.6.4 Earth electrode installation records 8 R B U I D d B R D C [ U I d d I U D E C F B W E F R � D C W d V R D C G R B U I D d [ E K U H B B I F U H D C G I F F I C G B J B C U � [ H I d d _ B � B \ U E K I d d B c V D \ J B C UD C [ U I d d I U D E C [ Q H B F B I J I D C B I F U H B d B W U F E R B W E C K D G V F I U D E C H I [ _ B B C D J \ d B J B C U B R S> H D [ [ H I d d D C W d V R B OI N [ E D d F B [ D [ U D ] D U Z [ V F ] B Z F B [ V d U [ ³_ N B I F U H B d B W U F E R B W E C K D G V F I U D E C I C R R D J B C [ D E C [ ³W N B c V D \ J B C U R B U I D d [ ³R N J B I [ V F B R F B [ D [ U I C W B E K U H B B I F U H B d B W U F E R B D C [ U I d d I U D E C U E B I F U H L Q H B F B F B c V D F B R N ³ I C RB N 1 F E � B W U 4 C G D C B B F D C G 5 B \ I F U J B C U D C ] B [ U D G I U D E C F B [ V d U [ I C R F B W E J J B C R I U D E C [ L Q H B F B I \ \ d D W I _ d B N S8 C C B M 4 W E C U I D C [ F B W E J J B C R B R K E F J I U [ E K D C [ U I d d I U D E C F B W E F R [ I C R J B R D V J ] E d U I G B B c V D \ J B C UW E J J D [ [ D E C D C G [ H B B U [ S 9 B K B F U E I C C B M 8 K E F G V D R I C W B E C [ E D d D R B C U D K D W I U D E C S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �22 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

4.7 Connections to earth electrodes . E C C B W U D E C [ U E B I F U H B d B W U F E R B [ [ H I d d W E J \ d Z Q D U H U H B K E d d E Q D C G OI N I d d C E F J I d d Z I W W B [ [ D _ d B B I F U H D C G U B F J D C I U D E C [ U E B c V D \ J B C U [ H I d d _ B J I R B Q D U H W E J \ F B [ [ D E C d V G [E F _ E d U B R W d I J \ [ ³_ N I d d B I F U H D C G W E C C B W U D E C [ U E B c V D \ J B C U [ H I d d _ B [ E I F F I C G B R U H I U U H B Z W I C _ B F B J E ] B R �\ B F J I C B C U d Z E F U B J \ E F I F D d Z � D C R B \ B C R B C U d Z E K I C Z E U H B F B I F U H ³ I C RW N U H B C V J _ B F E K W E C C B W U D E C [ U E I C B I F U H W E C R V W U E F [ H I d d _ B � B \ U U E I J D C D J V J S4.8 Materials for earthing applications 9 B d B ] I C U W E J \ E C B C U R B [ D G C R F I Q D C G [ I F B d D [ U B R D C I C C B M ; S> H B \ F B K B F F B R J I U B F D I d [ U E _ B V [ B R K E F B I F U H D C G I \ \ d D W I U D E C [ I F B I [ K E d d E Q [ S4.8.1 Conductors

4.8.1.1 Standard conductors (see D-DT-3137 and D-DT-3139) > H B W E C R V W U E F V [ B R K E F B I F U H D C G d B I R [ I C R B I F U H _ E C R D C G W E C R V W U E F [ H I d d _ B I C C B I d B R [ U F I C R B R E F [ E d D RW E \ \ B F W E C R V W U E F S 8 J D C D J V J W F E [ [ [ B W U D E C I d I F B I E K a b J J ± [ U F I C R B R W E \ \ B F E F a T J J ± [ E d D R W E \ \ B F [ H I d d_ B V [ B R S; E F C B Q D C [ U I d d I U D E C [ � U H B B I F U H D C G d B I R [ H I d d _ B I � E D C U i K F B B W E C U D C V E V [ W E C R V W U E F S ; E F F B U F E K D U [ � \ B F J D [ [ D E C[ H I d d _ B E _ U I D C B R K F E J U H B 1 F E � B W U 4 C G D C B B F D C G 5 B \ I F U J B C U U E H I ] B � E D C U [ E C U H B B I F U H D C G d B I R [ S. E C R V W U E F [ K E F B I F U H D C G I \ \ d D W I U D E C [ I F B [ B d B W U B R I W W E F R D C G U E U H B D F J I M D J V J I d d E Q I _ d B U B J \ B F I U V F B F D [ BK E F U H B K d E Q E K ` f @ � W V F F B C U S > H B J D C D J I d W F E [ [ [ B W U D E C I d I F B I D [ [ \ B W D K D B R U E B C [ V F B J B W H I C D W I d D C U B G F D U Z E KU H B W E C R V W U E F I K U B F U H B I \ \ d D W I U D E C E K W E J \ F B [ [ B R d V G [ E F B M E U H B F J D W Q B d R D C G S> H B [ H E F U U D J B L X [ N W V F F B C U F I U D C G [ K E F [ U F I C R B R W E \ \ B F W E C R V W U E F [ D C I W W E F R I C W B Q D U H? 8 = ? a f a h e i X � I F B d D [ U B R D C U I _ d B b S

Table 6 – Short time current ratings (3 s) for stranded copper conductors

Cross sectional area

Stranding/diameter

Maximum current ́� � µ ¶

for given maximum

Final conductor temperature ö ö � ü � � � ö ö º � � � » º � � � ½ *� º» �½ ¼� � � �

¹ � õ ¹ �¹ � � õ �¹ � � õ ½ º¹ � ¼ õ ¼ º¹ � ¼ õ ¹ º ø � � õ � º � � � � ¹ º¼ � � �» ¹ º �½ � � �¹ º � �

ø ¹ º¼ � �» ø º �¹ � � �ø ø � º � º � � � ï � � ì � � � �

µ î î é � ê ñ ô é ë � ¸ � � � � é ñ ë ì ê � � ì ê ë � � � ñ � ì � � ñ � ñ � � ï ì � í ð � ñ � � ´ � ó � ê ó ö ñ í ô ñ � � é í � ð � � ë ì ¶ �� µ î î é � ê ñ ô é ë � ô ñ � ê � � ì ê ë � � � � � ë ó ô � ñ � ì ê � � � ê ë � � � �

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �23 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

4.8.1.2 Alternative conductors 2 C I F B I [ Q H B F B U H B U H B K U E K W E \ \ B F W E C R V W U E F [ D [ I \ F E _ d B J � W E C R V W U E F [ E K I d U B F C I U D ] B J I U B F D I d [ J I Z _ BW E C [ D R B F B R S 2 C J E [ U [ D U V I U D E C [ D U [ H E V d R _ B [ V K K D W D B C U U E V [ B I d U B F C I U D ] B W E C R V W U E F [ E C d Z K E F U H B B I F U H D C GR E Q C d B I R S ; E F B I [ B E K I \ \ d D W I U D E C I U U F I C [ K E F J B F D C [ U I d d I U D E C [ � U H B I d U B F C I U D ] B W E C R V W U E F J I Z I d [ E _ B V [ B RU E E _ U I D C U H B ` J [ B \ I F I U D E C _ B U Q B B C 0 : I C R 3 : U F I C [ K E F J B F B I F U H [ S. E \ \ B F i W d I R [ U B B d W E C R V W U E F L 5 i 5 > i X a X g N D [ U H B E C d Z F B W E J J B C R B R I d U B F C I U D ] B J I U B F D I d K E F B I F U H D C GI \ \ d D W I U D E C [ SNOTE 1: u t � u p � � o q � y o o t � r p q � � y r w � n u t t p r y � o � � o q v r w � o w x u p o p y o u w y n � p � u � � t � � u y � r p � � u t � u p � � o q � y o o t � � � w r p o y rr ¾ � q u y � r p u p q � r w w r q o � � u � w � v � � � u t t � y r x u p � x o y u t � � u t � u p � � � r w w r � � r p � � u p o � � o � � u t t � � o w � r � � � r p � o w p s n o w o y n o � u t � u p � � o q� y o o t � � � � w � o q � p y n o � � � � p � y � r v � r � � o w � r p q � � y r w � �NOTE 2: u t � u p � � o q � y o o t � r p q � � y r w � � � o q y o x � r w u w � t � � p o u w y n � p � u � � t � � u y � r p � � n u t t � o w o � t u � o q s � y n � p y n w o o x r p y n � r vu � � t � � u y � r p �> H B [ H E F U U D J B L X [ N W V F F B C U F I U D C G K E F ` � a h J J R D I J B U B F � X f � W E C R V W U D ] D U Z W E \ \ B F i W d I R [ U B B d W E C R V W U E F D [G D ] B C D C U I _ d B b I S

Table 6a – Short time current ratings (3 s) for copper-clad steel conductor

Diameter ́ö ö

) Maximum current ́� � µ ¶

for 150 C1

Final conductor temperature º õ ø ø � ��

µ î î é � ê ñ ô é ë � ¸ � � � � é ñ ë ì ê � î î � � ê é ñ ì � ë é ê � � ì ê ë � � � �9 B K B F U E I C C B M 5 K E F R B U I D d [ F B G I F R D C G U H B W E C R V W U E F W F E [ [ i [ B W U D E C I d I F B I [ \ B W D K D W I U D E C [ \ F B [ B C U B R D C U I _ d B [b I C R b I S4.8.1.3 Conductor insulation > H B B I F U H d B I R [ V [ B R U E E _ U I D C U H B [ B \ I F I U D E C _ B U Q B B C U H B 0 : I C R 3 : B d B W U F E R B [ I U U F I C [ K E F J B FD C [ U I d d I U D E C [ [ H I d d _ B D C [ V d I U B R Q D U H I _ d I W � � a f f f : � V d U F I i ] D E d B U [ U I _ D d D � B R � 1 : . W E ] B F D C G S > H B 1 : . W E ] B F D C GI C R W E \ \ B F [ H I d d W E J \ d Z Q D U H ? 8 = ? a ^ a a i g S4.8.2 Earth rods and accessories 4 I F U H F E R [ I C R I W W B [ [ E F D B [ [ H I d d W E J \ d Z Q D U H U H B K E d d E Q D C G O4.8.2.1 Earth rods 4 I F U H F E R [ L B M U B C R I _ d B E F C E C i B M U B C R I _ d B N [ H I d d W E J \ d Z Q D U H 5 i 5 > i X f h a S ? B B I _ E ] B S4.8.2.2 Couplings . E V \ d D C G [ L U H F B I R B R E F U H F B I R d B [ [ N [ H I d d W E J \ d Z Q D U H 5 i 5 > i X f h T

.

4.8.2.3 Driving tips 5 F D ] D C G U D \ [ [ H I d d _ B J I C V K I W U V F B R K F E J H D G H [ U F B C G U H [ U B B d E K d B C G U H I R B c V I U B U E J I � B I W E C U I W U Q D U H U H BF E R Q H D d B R F D ] D C G S4.8.2.4 Driving studs 5 F D ] D C G [ U V R [ [ H I d d _ B J I C V K I W U V F B R K F E J H D G H i U B C [ D d B [ U B B d K E F R F D ] D C G E K U H F B I R B R B I F U H i F E R [ S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �24 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

4.8.2.5 Driving heads 5 F D ] D C G H B I R [ [ H I d d _ B J I C V K I W U V F B R K F E J H D G H i U B C [ D d B [ U B B d K E F R F D ] D C G B I F U H F E R [ Q D U H V C U H F B I R B R B C R [ S4.8.3 Connectors 2 U D [ \ F B K B F F B R U H I U I d d _ E C R [ Q D U H D C I C B I F U H D C G [ Z [ U B J _ B J I R B ] D I I W F D J \ B R � _ E d U B R E F B M E U H B F J D W Q B d R B RW E C C B W U D E C S > H B K E d d E Q D C G W E C C B W U E F [ I F B [ V D U I _ d B K E F V [ B E C _ E U H W E \ \ B F I C R W E \ \ B F i W d I R [ U B B dW E C R V W U E F [ S4.8.3.1 Underground connections I N . E C C B W U D E C [ U E B I F U H F E R [ O. E C R V W U E F U E F E R W F D J \ B R W E C C B W U D E C L \ F B K B F F B R N L [ B B 5 i 5 > i X f g b N �? V D U I _ d B K E F V [ B Q D U H E C B a b J J T W E C R V W U E F I C R I a b J J R D I J B U B F B I F U H F E R ³4 M E U H B F J D W Q B d R B R W E C C B W U D E C �. E C R V W U E F U E F E R W d I J \ L [ B B 5 i 5 > i X f h X N �? V D U I _ d B K E F V [ B Q D U H W E C R V W U E F E K J I M D J V J W F E [ [ [ B W U D E C I d I F B I E K g f J J ± I C R I a b J JR D I J B U B F B I F U H F E R S > H B W d I J \ _ E d U [ H I d d _ B U D G H U B C B R E C U E U H B B I F U H F E R � C E U U H B W E \ \ B F d B I R ³_ N . E C C B W U D E C [ K E F B I F U H D C G W E C R V W U E F [ O. F D J \ D C G K B F F V d B L \ F B K B F F B R N L [ B B 5 i 5 > i X f g b N? H I d d _ B V [ B R Q D U H K E V F a b J J � W E C R V W U E F [ S > H B K B F F V d B D [ W F D J \ B R V [ D C G I a ^ � ` @ 4 � I W F E [ [K d I U [ R D B I C R I H I d K i U E C H Z R F I V d D W W F D J \ D C G U E E d L U H B [ I J B U E E d I [ D [ V [ B R K E F 8 6 . � E D C U [ I C RU B F J D C I U D E C [ N ³3 D C B U I \ L [ B B 5 i 5 > i X a f a N? V D U I _ d B K E F W E C C B W U D E C E K [ U F I C R B R W E C R V W U E F E K R D I J B U B F [ V \ U E h J J ³4.8.3.2 Connections above ground level I N > F I C [ K E F J B F d D C B U I \ L [ B B 5 i 5 > i X f ^ e N? V D U I _ d B K E F W E C C B W U D E C E K [ U F I C R B R W E C R V W U E F E K R D I J B U B F [ V \ U E h J J ³_ N 3 D C B U I \ L [ B B 5 i 5 > i X a f a NW N . F D J \ D C G d V G L [ B B 5 i 5 > i X a f T N ? V D U I _ d B K E F a b J J W E C R V W U E F R D I J B U B F K E F I U U I W H J B C U U E 0 a TB I F U H D C G [ U V R E C I U F I C [ K E F J B F U I C � S4.8.4 Neutral surge arrester > H B [ \ B W D K D W I U D E C E K U H B C B V U F I d [ V F G B I F F B [ U B F L [ B B 5 i 5 > i X f e e N F B c V D F B R I U U F I C [ K E F J B F D C [ U I d d I U D E C [ Q D U H[ B \ I F I U B 0 : I C R 3 : B I F U H [ D [ I [ K E d d E Q [ OI N U Z \ B O 0 B U I d E M D R B ³_ N W d I [ [ O 5 D [ U F D _ V U D E C ³W N 0 . / : � O ` � : ³R N E \ B F I U D C G ] E d U I G B O b � : ³B N R D [ W H I F G B W V F F B C U O a f � 8 ³ I C RK N \ F E U B W U D ] B d B ] B d � O a h � ` � : SNOTE 1

¥ ° u ¾ � x � x � r p y � p � r � � r � o w u y � p � ¡ � r t y u � o �NOTE 2 � � o w � � o q v r w u ¢ ­ § { � ® � � ­ � � x � � t � o �

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �25 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

4.8.5 Earth lead fastening 4 I F U H d B I R [ [ H I d d _ B K I [ U B C B R U E Q E E R \ E d B [ V [ D C G G I d ] I C D � B R Q D F B [ U I \ d B [ L [ B B 5 i 5 > i X a T h N [ \ I W B R B ] B F Z` f f J J S4.8.6 Stay insulators ? U I Z [ E C I d d 0 : R D [ U F D _ V U D E C C B U Q E F � [ I C R 3 : K B B R B F [ [ H I d d _ B K D U U B R Q D U H I [ U I Z D C [ V d I U E F S

5 Measurement guide

5.1 Apparatus for earth tests

5.1.1 Earth testing instruments

5.1.1.1 Requirements of an earth testing instrument 8 C B I F U H U B [ U D C G D C [ U F V J B C U [ H I d d W E J \ d Z Q D U H U H B K E d d E Q D C G F B c V D F B J B C U [ OI N [ \ B W D I d B I F U H U B [ U D C G D C [ U F V J B C U [ R B [ D G C B R K E F U H B \ I F U D W V d I F K E F J E K J B I [ V F B J B C U [ H I d d _ B V [ B R ³_ N U H B \ F D C W D \ d B E K B I F U H U B [ U B F E \ B F I U D E C D [ U E J B I [ V F B W V F F B C U \ I [ [ D C G U H F E V G H U H B W D F W V D U W E C U I D C D C GU H B F B [ D [ U I C W B V C R B F U B [ U I C R U H B ] E d U I G B I W F E [ [ U H D [ F B [ D [ U I C W B S > H B J B I [ V F B R c V I C U D U D B [ [ H I d dU H B C _ B \ F E W B [ [ B R _ Z U H B D C [ U F V J B C U U E G D ] B U H B ] I d V B E K U H B F B [ D [ U I C W B D C E H J [ ³W N U H B D C [ U F V J B C U [ H I d d W E C U I D C D U [ E Q C [ E V F W B E K [ V \ \ d Z � B D U H B F I H I C R i R F D ] B C G B C B F I U E F E F D C U B F C I d_ I U U B F D B [ S 8 C I d U B F C I U D C G W V F F B C U [ H I d d _ B G B C B F I U B R S 2 C [ D U V I U D E C [ Q H B F B U H B [ E D d F B [ D [ U D ] D U Z D [ H D G H �[ U I C R I F R B I F U H U B [ U B F [ J I Z C E U _ B I _ d B U E G B C B F I U B B C E V G H ] E d U I G B U E R F D ] B I C I R B c V I U B U B [ UW V F F B C U S ? B B ` S a S T K E F K V F U H B F R B U I D d [ ³R N U H B D C [ U F V J B C U [ H I d d H I ] B K E V F U B F J D C I d [ U E Q H D W H U H B U B [ U d B I R [ W I C _ B W E C C B W U B R S > Q E U B F J D C I d [[ H I d d _ B K E F \ I [ [ D C G U H B W V F F B C U U E U H B W D F W V D U I C R U Q E [ H I d d _ B K E F R B U B W U D C G U H B \ E U B C U D I d R F E \I W F E [ [ U H B J B I [ V F B R F B [ D [ U I C W B S > H B W V F F B C U U B F J D C I d [ [ H I d d _ B J I F � B R . a I C R . T I C R U H B\ E U B C U D I d U B F J D C I d [ [ H I d d _ B J I F � B R 1 a I C R 1 T ³B N K E F B I [ B E K E \ B F I U D E C I C R B d D J D C I U D E C E K \ E [ [ D _ d B F B I R D C G B F F E F [ U H B � R D F B W U F B I R D C G � 3 D c V D R . F Z [ U I d5 D [ \ d I Z L 3 . 5 N U B [ U B F [ I F B \ F B K B F F B R S > B [ U B F [ E \ B F I U D C G E C U H B � C V d d i _ I d I C W B � \ F D C W D \ d B I F BI W W B \ U I _ d B ³K N F B [ D [ U I C W B F B I R D C G [ K F E J f � f a U E a h h h [ H I d d _ B E _ U I D C I _ d B ³G N I C D C [ U F V J B C U [ H I d d _ B I _ d B U E F B W E F R J B I [ V F B J B C U [ D C U H B E F R B F E K T f � T f f I C R T f f f ³H N E \ U D E C I d K B I U V F B [ I F B I ] I D d I _ d B E C [ E J B B I F U H U B [ U B F [ D C R D W I U D C G OU H B W V F F B C U \ F E _ B F B [ D [ U I C W B _ B D C G U E E H D G H �U H B \ E U B C U D I d \ F E _ B F B [ D [ U I C W B _ B D C G U E E H D G H �U H B _ I U U B F Z W I \ I W D U Z _ B D C G d E Q E F U H B G B C B F I U E F _ B D C G U V F C B R U E E [ d E Q d Z � I C RU H B B M W B [ [ D ] B C E D [ B D C U B F K B F B C W B D C U H B [ E D d _ B D C G U B [ U B R S8 [ I W E [ U B K K B W U D ] B I d U B F C I U D ] B K E F U B I J [ W E C W B F C B R Q D U H F E V U D C B J I D C U B C I C W B U B [ U D C G E K U H B B I F U H W E C C B W U D E CW E C U D C V D U Z I C R B I F U H B d B W U F E R B F B [ D [ U I C W B � I U H F B B U B F J D C I d R D F B W U F B I R D C G U B [ U B F Q D U H E C B J B I [ V F B J B C UF I C G B I C R F B I R D C G [ E K F B [ D [ U I C W B E K f � T U E ` f f Q D d d _ B [ V K K D W D B C U S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �26 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

5.1.1.2 Operation of a typical earth testing instrument > H B D C [ U F V J B C U [ H I d d _ B W E C C B W U B R K E F U H B [ \ B W D K D W U B [ U F B c V D F B R S > H B E \ B F I U D E C E K U Z \ D W I d D C [ U F V J B C U [ D [R B [ W F D _ B R _ B d E Q S ; E F J E F B R B U I D d B R D C [ U F V W U D E C [ W E C [ V d U U H B E \ B F I U D C G J I C V I d K E F U H B [ \ B W D K D W D C [ U F V J B C U S I N / \ B F I U D E C E K � = V d d i _ I d I C W B � D C [ U F V J B C U [[ B U U H B F I C G B [ Q D U W H U E f � f a I C R U H B _ I d I C W D C G F B [ D [ U E F R D I d [ U E h h h �U V F C U H B G B C B F I U E F [ d E Q d Z � \ F B [ [ U H B U B [ U _ V U U E C I C R C E U B U H B G I d ] I C E J B U B F R B K d B W U D E C �D K R B K d B W U D E C D [ \ E [ D U D ] B L U E Q I F R [ � N � D C W F B I [ B F I C G B K I W U E F U E f � a L E F H D G H B F N V C U D d U H BR B K d B W U D E C _ B W E J B [ C B G I U D ] B L U E Q I F R [ N �Q H B C R B K d B W U D E C D [ C B G I U D ] B R B W F B I [ B U H B ] I d V B E K U H B F B [ D [ U E F � R D G D U _ Z R D G D U � [ U I F U D C G Q D U HU H B d B K U � C E _ � U H B C U H B W B C U F B I C R K D C I d d Z U H B F D G H U � C E _ S . E C U D C V B V C U D d U H B G I d ] I C E J B U B F\ E D C U B F D [ W B C U F I d S ? \ B B R V \ U H B F B ] E d V U D E C [ E K U H B G B C B F I U E F U E I _ E V U a b f F \ J K E FJ I M D J V J [ B C [ D U D ] D U Z I C R U E I ] E D R U H B B K K B W U [ E K [ U F I Z W V F F B C U [ � I C RU H B ] I d V B E K F B [ D [ U I C W B V C R B F U B [ U D [ B [ U I _ d D [ H B R _ Z F B I R D C G U H B _ I d I C W B F B [ D [ U E F R D I d [ I C RJ V d U D \ d Z D C G D U _ Z U H B F I C G B K I W U E F S_ N / \ B F I U D E C E K R D F B W U F B I R D C G D C [ U F V J B C U [[ B U U H B F I C G B [ Q D U W H U E D U [ d E Q B [ U [ B U U D C G �U V F C U H B G B C B F I U E F E F \ F B [ [ U H B U B [ U _ V U U E C I C R C E U B U H B F B [ D [ U I C W B ] I d V B E C U H B [ W I d B �D K U H B F B I R D C G D [ G E D C G E V U E K F I C G B � W H I C G B U H B F I C G B [ Q D U W H U E U H B H D G H B F ] I d V B � I C RU H B ] I d V B E K F B [ D [ U I C W B V C R B F U B [ U D [ F B I R R D F B W U d Z K F E J U H B [ W I d B S

5.1.1.3 Calibration of a typical earth testing instrument 4 ] B F Z B I F U H

U B [ U D C G D C [ U F V J B C U [ H I d d J I D C U I D C I C I \ \ F E \ F D I U B J B I [ V F B J B C U I W W V F I W Z S > E ] B F D K Z U H D [I W W V F I W Z � B I F U H U B [ U B F [ [ H I d d _ B W I d D _ F I U B R _ Z I = I U D E C I d . I d D _ F I U D E C ? B F ] D W B L = . ? N d I _ E F I U E F Z E C I C I C C V I d_ I [ D [ S. I d D _ F I U D E C W B F U D K D W I U B [ [ H I d d W E C U I D C U H B K E d d E Q D C G D C K E F J I U D E C OI N U H B [ B F D I d C V J _ B F � U Z \ B I C R I W W V F I W Z E K B c V D \ J B C U V [ B R D C U H B W I d D _ F I U D E C ³_ N U H B [ B F D I d C V J _ B F � U Z \ B I C R I W W V F I W Z E K B c V D \ J B C U _ B D C G W I d D _ F I U B R ³W N U H B R I U B E K W I d D _ F I U D E C I C R R I U B K E F F B W I d D _ F I U D E C ³ I C RR N U H B [ D G C I U V F B E K I C I \ \ F E ] B R [ U I K K J B J _ B F E K U H B = . ? d I _ E F I U E F Z SNOTE:

¯ p t � o � � � � x o p y y n u y n u � � o o p � u t � � w u y o q � � u p å } � t u � r w u y r w � � � w o � r � p � � o q u � � o � p � u � � � w u y o � p y o w x � r v y n o t u s �5.1.2 Test probes > H B J B U H E R [ E K U B [ U D C G R B [ W F D _ B R D C U H B K E d d E Q D C G [ B W U D E C [ � F B c V D F B U H B V [ B E K W V F F B C U I C R ] E d U I G B U B [ UB d B W U F E R B [ I d E C G Q D U H U H B B I F U H U B [ U D C G D C [ U F V J B C U S > H B U B [ U \ F E _ B [ I F B C E F J I d d Z [ V \ \ d D B R U E G B U H B F Q D U H U H BJ B I [ V F D C G D C [ U F V J B C U S8 C B I F U H U B [ U D C G � D U [ H I d d W E C U I D C I U d B I [ U K E V F [ U B B d \ F E _ B [ E K J D C D J V J d B C G U H ^ ` f J J I C R J D C D J V J W F E [ [ i[ B W U D E C I d I F B I a ^ f J J ± S> B [ U \ F E _ B [ [ H I d d _ B H I J J B F B R D C U E U H B G F E V C R D C ] I F D E V [ W E C K D G V F I U D E C [ I C R U E ] I F D E V [ R B \ U H [ R B \ B C R D C GE C U H B [ \ B W D K D W J B I [ V F B J B C U _ B D C G V C R B F U I � B C S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �27 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Test probe resistance > H B F B [ D [ U I C W B [ U E B I F U H E K U H B \ E U B C U D I d \ F E _ B [ H I ] B d D U U d B D C K d V B C W B E C F B [ D [ U I C W B I C R F B [ D [ U D ] D U ZJ B I [ V F B J B C U [ [ D C W B ] E d U J B U B F [ E \ B F I U B Q D U H ] B F Z H D G H D C U B F C I d F B [ D [ U I C W B [ S2 C I d d U H B U B [ U [ R B [ W F D _ B R D C U H D [ [ B W U D E C � W V F F B C U D [ D C � B W U B R D C U E U H B B I F U H U H F E V G H U H B B I F U H B d B W U F E R B V C R B FU B [ U E F I W V F F B C U \ F E _ B I C R B M U F I W U B R U H F E V G H I W V F F B C U \ F E _ B S > H B J I G C D U V R B E K U H B U B [ U W V F F B C U K E F IW E C [ U I C U ] E d U I G B [ E V F W B D [ R B \ B C R B C U E C U H B [ V J E K U H B B d B W U F E R B I C R \ F E _ B F B [ D [ U I C W B [ S 2 C U H B W I [ B U H I UU H D [ W E J _ D C B R F B [ D [ U I C W B D [ ] B F Z d I F G B � U H B J I G C D U V R B E K U B [ U W V F F B C U U H I U K d E Q [ J I Z _ B d E Q B F U H I C U H BJ B I [ V F D C G D C [ U F V J B C U � [ [ B C [ D U D ] D U Z S 0 B I [ V F B J B C U [ U I � B C V [ D C G [ J I d d U B [ U W V F F B C U [ I F B I d [ E J E F B d D � B d Z U E _ BR D [ U E F U B R _ Z U H B \ F B [ B C W B E K [ U F I Z W V F F B C U [ L [ B B ` S T S a N S> H B \ F E _ d B J E K D C [ V K K D W D B C U U B [ U W V F F B C U J I Z _ B I d d B ] D I U B R _ Z E C B E K U Q E W E V F [ B [ E K I W U D E C O5.1.2.1 Decrease the current probe/s resistance to earth > H B F B [ D [ U I C W B E K I U B [ U \ F E _ B W I C _ B R B W F B I [ B R _ Z R F D ] D C G U H B F E R R B B \ B F D C U E U H B [ E D d � \ E V F D C G Q I U B FI F E V C R U H B F E R E F _ Z R F D ] D C G I R R D U D E C I d F E R [ I C R D C U B F W E C C B W U D C G U H B J D C \ I F I d d B d S > H B I R R D U D E C E K [ I d U U E U H BQ I U B F \ E V F B R I F E V C R U H B U B [ U B d B W U F E R B [ R E B [ d D U U d B U E R B W F B I [ B U H B B d B W U F E R B F B [ D [ U I C W B S2 C [ E J B W I [ B [ W I F B [ H I d d _ B B M B F W D [ B R Q H B C D C [ U I d d D C G I C B M \ I C [ D ] B W V F F B C U \ F E _ B S � D U H \ I F U D W V d I F F B K B F B C W BU E U H B � B C C B F J B U H E R E K [ E D d F B [ D [ U D ] D U Z J B I [ V F B J B C U � U H B U B W H C D c V B D [ _ I [ B R E C I C I [ [ V J \ U D E C U H I U U H BW V F F B C U \ F E _ B [ H I ] B [ \ B W D K D W R D J B C [ D E C [ S < [ B E K B d B W U F E R B [ E K R D K K B F B C U R D J B C [ D E C [ Q D d d U H V [ D C U F E R V W B IJ B I [ V F B J B C U B F F E F S 2 C J I C Z W I [ B [ � U H B d D � B d D H E E R E K [ V W H B F F E F [ [ H I d d _ B Q B D G H B R I G I D C [ U U H B I d U B F C I U D ] B E KE _ U I D C D C G C E J B I [ V F B J B C U I U I d d S5.1.2.2 Increase the voltage of the power supply 2 C W F B I [ D C G U H B \ E Q B F [ V \ \ d Z ] E d U I G B D [ C E U \ E [ [ D _ d B Q H B C V [ D C G I H I C R R F D ] B C G B C B F I U E F E K U H B U Z \ BD C W E F \ E F I U B R D C [ E J B J B I [ V F D C G D C [ U F V J B C U [ S 2 C W I [ B [ Q H B F B D U D [ C E U \ E [ [ D _ d B U E I R B c V I U B d Z R B W F B I [ B U H B\ F E _ B F B [ D [ U I C W B � B I F U H U B [ U D C G J I Z _ B W I F F D B R E V U _ Z V [ D C G I [ B d B W U I _ d B K F B c V B C W Z \ E Q B F [ E V F W B U E G B U H B FQ D U H I [ U B \ i V \ U F I C [ K E F J B F S > H B U B [ U W V F F B C U D [ W I d W V d I U B R _ Z J B I [ V F D C G U H B ] E d U I G B I W F E [ [ I � C E Q CF B [ D [ U I C W B S� H B C U H D [ [ E d V U D E C D [ \ F I W U D W I d � W I F B [ H I d d _ B U I � B C U E I ] E D R W E C U I W U I W F E [ [ R I C G B F E V [ \ E U B C U D I d [ E C U H BB d B W U F E R B [ I C R U B [ U d B I R [ S8 [ I G B C B F I d F V d B U H B F B [ D [ U I C W B ] I d V B [ E K U H B W V F F B C U I C R \ E U B C U D I d B d B W U F E R B [ [ H I d d J B B U U H B F B c V D F B J B C U [E K U H B D C [ U F V J B C U [ V [ B R S � D U H W E J J B F W D I d D C [ U F V J B C U [ � I \ E U B C U D I d B d B W U F E R B F B [ D [ U I C W B E K a � J I Z _ BV [ B R S ? E J B J I C V K I W U V F B F [ W d I D J U H I U U H B D F D C [ U F V J B C U Q D d d \ B F J D U a f � D C U H B \ E U B C U D I d B d B W U F E R B S5.1.3 Other earth testing accessories > E G B U H B F Q D U H U H B J B I [ V F D C G D C [ U F V J B C U I C R U B [ U \ F E _ B [ � I J D C D J V J B I F U H U B [ U D C G � D U [ H I d d W E J \ F D [ B U H BK E d d E Q D C G OI N U Q E ` f J I C R U Q E a f f J d B I R [ B I W H Q D U H U Q E U Z \ B [ E K W E C C B W U E F [ j I [ \ I R B W E C C B W U E F K E FI U U I W H J B C U U E U H B U B [ U B F U B F J D C I d [ E C E C B [ D R B I C R U H B � W F E W E R D d B � U Z \ B W d D \ K E F I U U I W H J B C U U E U H BB I F U H F E R I U U H B E U H B F B C R ³_ N U Q E X J d B I R [ I d [ E Q D U H W E C C B W U E F [ ³W N E C B H I J J B F � a X � G L T � ` d _ S N ³R N U Q E \ F E _ B B M U F I W U E F [ ³B N E C B C E C i J B U I d d D W � b f J U I \ B J B I [ V F B ³ I C RK N I W E J J D [ [ D E C D C G [ H B B U L D C [ U I d d I U D E C F B W E F R N S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �28 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

5.2 Factors affecting measurement accuracy

5.2.1 Stray alternating currents ? U F I Z I d U B F C I U D C G W V F F B C U [ U H I U K d E Q D C U H B B I F U H J I Z E F D G D C I U B K F E J I C V J _ B F E K R D K K B F B C U [ E V F W B [ S > H B [ B[ E V F W B [ D C W d V R B OI N R D K K B F B C U D I d [ I d D C I U D E C D C [ E D d [ ³_ N R D K K B F B C U D I d I B F I U D E C E K [ E D d [ ³W N _ I W U B F D E d E G D W I d I W U D E C D C [ E D d [ ³R N R D K K B F B C U J I U B F D I d [ D C W E C U I W U Q D U H E C B I C E U H B F � K E F B M I J \ d B � G I d ] I C D W I W U D E C ³B N \ E Q B F [ V \ \ d Z [ Z [ U B J [ ³K N U F I W U D E C [ Z [ U B J [ � U F I J Q I Z [ � F I \ D R U F I C [ D U [ Z [ U B J [ � F I D d Q I Z [ ³ I C RG N R E J B [ U D W [ V \ \ d D B [ U H I U B J \ d E Z C B V U F I d E F B I F U H W E C R V W U E F [ L E F _ E U H N U H I U I F B W E C C B W U B R U E B I F U H I UJ V d U D \ d B d E W I U D E C [ S? U F I Z W V F F B C U [ U B C R U E R D [ U E F U U H B J B I [ V F B J B C U [ E K B I F U H D C G F B d I U B R c V I C U D U D B [ _ Z D C U F E R V W D C G ] E d U I G B R F E \ [I W F E [ [ U H B B d B W U F E R B E F [ E D d [ I J \ d B V C R B F U B [ U U H I U I F B C E U F B d I U B R U E U H B I \ \ d D B R U B [ U W V F F B C U S ? U F I Z W V F F B C U [I F B U H V [ F B [ \ E C [ D _ d B K E F U H B B M I G G B F I U B R F B [ D [ U I C W B I C R F B [ D [ U D ] D U Z J B I [ V F B J B C U [ S> H B B K K B W U [ E K [ U F I Z I d U B F C I U D C G W V F F B C U J I Z _ B F B R V W B R D C B I F U H D C G F B d I U B R J B I [ V F B J B C U [ _ Z V U D d D � D C G I U B [ UK F B c V B C W Z U H I U D [ C E U \ F B [ B C U D C U H B [ U F I Z W V F F B C U S 0 E [ U J B I [ V F D C G R B ] D W B [ V [ B K F B c V B C W D B [ Q D U H D C I F I C G BE K ` f @ � U E a f f @ � S > H B V [ B E K K D d U B F [ E F C I F F E Q _ I C R J B I [ V F D C G D C [ U F V J B C U [ D [ I C E U H B F J B U H E R E KE ] B F W E J D C G U H B B K K B W U [ E K [ U F I Z I d U B F C I U D C G W V F F B C U [ S5.2.2 Coupling between test leads 2 C W I [ B [ Q H B F B W V F F B C U I C R ] E d U I G B d B I R [ E K [ V _ [ U I C U D I d d B C G U H I F B d I D R I R � I W B C U d Z I [ D C I d d U B [ U \ F E W B R V F B [R B [ W F D _ B R H B F B D C � U H B F B D [ I R D [ U D C W U \ E [ [ D _ D d D U Z U H I U d B I � I G B W V F F B C U J I Z _ B D C R V W B R D C U H B \ E U B C U D I d d B I R S> H D [ W V F F B C U d B I � I G B D [ I C D J \ E F U I C U K I W U E F U H I U G D ] B [ F D [ B U E J B I [ V F B J B C U B F F E F [ S> H B J E [ U E _ ] D E V [ \ F B W I V U D E C U E F B R V W B U H B d D � B d D H E E R E K D C R V W B R W V F F B C U [ D [ U E B C [ V F B U H I U U H B d B I RD C [ V d I U D E C D [ D C G E E R W E C R D U D E C S> H B B K K B W U E K U H B J B I [ V F B J B C U B F F E F F B [ V d U D C G K F E J W E V \ d D C G _ B U Q B B C U H B U B [ U d B I R [ D [ d D � B d Z U E _ B J E [ U\ F E C E V C W B R Q H B C J B I [ V F D C G d E Q F B [ D [ U I C W B ] I d V B [ S 2 C U H B [ B W I [ B [ D U D [ G E E R \ F I W U D W B U E B C [ V F B I a f f J J[ B \ I F I U D E C _ B U Q B B C W V F F B C U I C R \ E U B C U D I d d B I R [ S5.2.3 Fences and buried metallic objects 0 B U I d d D W [ U F V W U V F B [ C B I F U E U H B U B [ U I F B I J I Z D C ] I d D R I U B U H B U B [ U F B [ V d U [ S � H B F B \ E [ [ D _ d B � U B [ U D C G [ H I d d _ BW I F F D B R E V U I Q I Z K F E J J I C i J I R B [ U F V W U V F B [ [ V W H I [ \ D \ B d D C B [ I C R K B C W B [ S 2 K I \ D \ B d D C B E F K B C W B W F E [ [ B [U H B U B [ U [ D U B � U H B R D F B W U D E C E K U H B d D C B K E F J B R _ Z U H B U B [ U \ F E _ B [ [ H I d d _ B W H E [ B C U E _ B \ B F \ B C R D W V d I F U E U H BR D F B W U D E C E K U H B J B U I d [ U F V W U V F B S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �29 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

5.3 Soil resistivity measurement > H B F B [ D [ U D ] D U Z E K [ E D d D [ R B \ B C R B C U E C D U [ W E J \ E [ D U D E C I C R J E D [ U V F B W E C U B C U S > H B [ B K I W U E F [ [ H E Q Q D R B] I F D I C W B K F E J \ d I W B U E \ d I W B I C R E ] B F U D J B S > H B F B [ D [ U D ] D U Z E K U H B [ E D d [ V F F E V C R D C G I C B I F U H B d B W U F E R B H I [ I[ D G C D K D W I C U D J \ I W U E C U H B F B [ D [ U I C W B E K I C B I F U H B d B W U F E R B S ? E D d F B [ D [ U D ] D U Z I d [ E H I [ I _ B I F D C G E C U H B \ E U B C U D I dG F I R D B C U [ U H I U I F B U E _ B B M \ B W U B R I U U H B [ E D d [ V F K I W B R V F D C G U D J B [ E K K I V d U W V F F B C U R D [ W H I F G B U H F E V G H U H B B I F U HB d B W U F E R B S> H B J B I [ V F B J B C U E K [ E D d F B [ D [ U D ] D U Z D [ I C D J \ E F U I C U K V C W U D E C U H I U \ d I Z [ I W F V W D I d F E d B D C U H B I \ \ d D W I U D E C E K I CB I F U H B d B W U F E R B S ? E D d F B [ D [ U D ] D U Z J B I [ V F B J B C U [ I F B I d [ E V [ B K V d D C U H B W I d W V d I U D E C E K U H B B M U B C U E K D C R V W U D ] BW E V \ d D C G _ B U Q B B C I R � I W B C U \ E Q B F I C R W E J J V C D W I U D E C W D F W V D U [ S? B ] B F I d J B U H E R [ I F B I ] I D d I _ d B _ Z Q H D W H [ E D d F B [ D [ U D ] D U Z J I Z _ B J B I [ V F B R S > H B \ F B K B F F B R U B W H C D c V B D [ U H B� B C C B F J B U H E R SThe Wenner method of soil resistivity measurement > H B � B C C B F J B U H E R L I d [ E � C E Q C I [ U H B ¿ K E V F B d B W U F E R B [ J B U H E R À N D [ U H B K I ] E V F B R U B W H C D c V B K E F J B I [ V F D C G[ E D d F B [ D [ U D ] D U Z I U I d E W I U D E C Q H B F B I C B I F U H B d B W U F E R B W E ] B F D C G I [ J I d d I F B I Q D d d _ B D C [ U I d d B R S> H B � B C C B F J B U H E R E \ B F I U B [ V C R B F U H B I [ [ V J \ U D E C U H I U U H B [ E D d D C Q H D W H U H B J B I [ V F B J B C U D [ J I R B D [H E J E G B C E V [ O U H I U D [ � I [ E D d E K V C D K E F J J I U B F D I d � W E C [ D [ U B C W Z � G F I D C [ D � B I C R R B C [ D U Z S 2 U Q D d d _ B [ B B C\ F B [ B C U d Z U H I U U H B J B U H E R H I [ [ E J B I \ \ d D W I U D E C D C [ E D d [ W E C [ D [ U D C G E K d I Z B F [ E K R D K K B F D C G F B [ D [ U D ] D U Z S5.3.1 Soil resistivity measurement procedure > H B J B I [ V F B J B C U \ F E W B R V F B D [ I [ K E d d E Q [ O5.3.1.1

; E V F U B [ U \ F E _ B [ [ H I d d _ B R F D ] B C D C U E U H B [ E D d D C I [ U F I D G H U d D C B I U B c V I d R D [ U I C W B [ � I � I C R U E IR B \ U H E K C E U J E F B U H I C a f � E K � I � L F B K B F U E K D G V F B X N S5.3.1.2

> H B d B I R [ _ B U Q B B C U H B J B I [ V F D C G D C [ U F V J B C U I C R U B [ U \ F E _ B [ I F B W E C C B W U B R I [ [ H E Q C D C ; D G V F BT S . I F B [ H I d d _ B B M B F W D [ B R U E B C [ V F B U H I U U H B D C [ V d I U B R d B I R [ I F B D C G E E R Q E F � D C G E F R B F I [ R I J I G B R E F C E C iD C [ V d I U B R d B I R [ J I Z F B [ V d U D C D C W E F F B W U ] I d V B [ _ B D C G F B W E F R B R S� � � �� � � �� � � � � � � � � �

! " # " # $ ! $% % % &' (Figure 3 – Connections for the Wenner method of soil resistivity measurement

5.3.1.3 > H B B I F U H U B [ U B F D [ E \ B F I U B R I C R I F B [ D [ U I C W B J B I [ V F B J B C U � 9 � D [ F B W E F R B R S

5.3.1.4 > H B I ] B F I G B [ E D d F B [ D [ U D ] D U Z U E I R B \ U H � 5 � D C U H B ] D W D C D U Z E K U H B ] E d U I G B \ F E _ B [ D [ W I d W V d I U B RI W W E F R D C G U E U H B F B d I U D E C O

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �30 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

8 ] B F I G B F B [ D [ U D ] D U Z U E R B \ U H 5 O ) T I 9 L J NQ H B F B � I � D [ U H B U B [ U \ F E _ B [ \ I W D C G D C J B U F B [ I C R � 9 � D [ U H B B I F U H U B [ U B F F B I R D C G [ D C E H J [ S > H B R B \ U H � 5 � D [G D ] B C I [ B D G H U Z \ B F W B C U E K U H B \ F E _ B [ \ I W D C G L D S B S 5 ) f � e I N S9 B I R D C G [ [ H I d d _ B U I � B C I C R F B [ D [ U D ] D U Z W I d W V d I U B R K E F \ F E G F B [ [ D ] B d Z Q D R B C B R \ F E _ B [ \ I W D C G [ U E E _ U I D CF B [ D [ U D ] D U Z ] I d V B [ I U ] I F D E V [ R B \ U H [ S > H B W B C U F B \ E [ D U D E C E K U H B [ \ D � B [ Z [ U B J [ H I d d _ B � B \ U W E C [ U I C U Q H D d [ UU H B \ F E _ B [ \ I W D C G [ I F B D C W F B I [ B R S > H B F B W E J J B C R B R ] I d V B [ K E F ¿ I À I F B OI N a J ³_ N T J ³W N X J ³R N ` J ³B N a f J ³ I C RK N a ` J S> H B R B \ U H U E Q H D W H U H B U B [ U \ F E _ B [ I F B R F D ] B C [ H I d d C B ] B F _ B J E F B U H I C a f � E K U H B [ \ I W D C G � I � _ B U Q B B CU H B B d B W U F E R B [ S> H B F B [ V d U [ [ H I d d _ B U I _ V d I U B R I [ [ H E Q C D C U I _ d B g S > H B [ \ B W D K D W R B \ U H � 5 � K E F I G D ] B C [ \ I W D C G � I � D [W I d W V d I U B R I [ O5 ) f � e I; E F B I [ Z W I d W V d I U D E C I G B E J B U F D W K I W U E F G D ] B C _ Z Y ) T I D [ \ F B [ B C U B R D C U H B U I _ d B S/ C W E J \ d B U D E C E K U H B U I _ d B � I W V F ] B E K F B [ D [ U D ] D U Z L D C E H J J B U F B [ N I G I D C [ U R B \ U H L D C J B U F B [ N D [ \ d E U U B R E C Id E G I F D U H J D W [ W I d B S > H B K E F J I U E K U H B G F I \ H D [ R D [ \ d I Z B R D C G F I \ H a I C R F B \ F E R V W B R D C I C C B M 4 S2 C I C I F B I � F B I R D C G [ [ H I d d _ B U I � B C D C I J D C D J V J E K U Q E R D K K B F B C U R D F B W U D E C [ STable 7 – Format for a soil resistivity survey results table � ¼ » º

Probe spacing ñ ´ ö ¶ Specific depth ý ÷ � õ � ñ ´ ö ¶ Tester reading � ´ ¶ Geometric factor K * ÷ � ñ Resistivity ´ ö ¶î ÷ � * � õ � ½ õ � �� õ ½ � õ º ¹¼ � õ » � õ � ºº » õ � ¼ õ » � � � õ � ½ � õ � ¼ º � õ � ø » õ � º

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �31 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

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Resistivity

ohm-m

� � � � ô � î ñ ê � � ð ´ ö ¶ � ¼ » º ½ ¹ � ø � � ¼ » ºþ î ê � ï � ê ì î ë ó ´ ö ¶ � õ � õ ½ � õ » ¼ õ � » õ � » õ � º õ ½ ½ õ » ¹ õ � � õ � � õ � ø õ ½ � õ � õ ½ � õ �Graph 1 – Format for an apparent soil resistivity graph

5.3.2 Interpretation of measured results > H B F B [ V d U [ E _ U I D C B R K F E J I [ E D d F B [ D [ U D ] D U Z J B I [ V F B J B C U G D ] B [ E J B D C R D W I U D E C E K U H B C I U V F B E K U H B V C R B F d Z D C G[ E D d S 2 K U H B F B [ D [ U D ] D U Z D [ K E V C R U E D C W F B I [ B F I \ D R d Z Q D U H D C W F B I [ B E K � I � � E C B J I Z R B R V W B U H I U U H B F B I F B d I Z B F [E K [ E D d H I ] D C G I H D G H B F F B [ D [ U D ] D U Z U H I C U H I U I U U H B [ V F K I W B S 8 ] B F Z F I \ D R D C W F B I [ B J I Z D C R D W I U B U H B \ F B [ B C W BE K F E W � S 2 C U H D [ W I [ B D U W E V d R _ B R D K K D W V d U U E D C [ U I d d I ] B F U D W I d B I F U H B d B W U F E R B I C R I H E F D � E C U I d B d B W U F E R B U Z \ B[ H E V d R _ B W E C [ D R B F B R S2 K U H B F B [ D [ U D ] D U Z R B W F B I [ B [ F I \ D R d Z Q D U H D C W F B I [ B R R B \ U H � U H B W E C W d V [ D E C W I C _ B R F I Q C U H I U U H B R B B \ B F d I Z B F [E K [ E D d H I ] B I d E Q B F F B [ D [ U D ] D U Z I C R I R ] I C U I G B Q D d d _ B G I D C B R _ Z D C [ U I d d D C G I R B B \ B I F U H B d B W U F E R B � K E FB M I J \ d B � I ] B F U D W I d B I F U H F E R S2 K U H B F B [ V d U [ D C R D W I U B I _ C E F J I d D U D B [ D C U H B [ E D d � I [ B W E C R [ B U E K U B [ U [ [ H I d d _ B W E C R V W U B R Q D U H U H B \ F E _ B [d D C B R V \ D C I R D K K B F B C U R D F B W U D E C S5.3.3 Two layer soils 2 K U H B I \ \ I F B C U [ E D d F B [ D [ U D ] D U Z G F I \ H [ H E Q [ [ D G C D K D W I C U ] I F D I U D E C E K U H B [ E D d F B [ D [ U D ] D U Z Q D U H R B \ U H U H B C D U Q D d d _ BC B W B [ [ I F Z U E W E C [ U F V W U I U Q E i d I Z B F [ E D d J E R B d K E F U H B [ E D d S > H D [ Q D d d G D ] B I C D C R D W I U D E C E K U H B F B [ D [ U D ] D U Z E K U H BV \ \ B F [ E D d d I Z B F L + N U H B F B [ D [ U D ] D U Z E K U H B d E Q B F [ E D d d I Z B F L , N I C R U H B R B \ U H E K U H B U E \ d I Z B F L H N S ? E K U Q I F B[ V W H I [ . 5 4 l ? J I Z _ B V [ B R U E R B U B F J D C B U H B J E R B d S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �32 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

5.4 Earth electrode resistance measurement 8 W W E F R D C G U E \ F E W B R V F B U E D C [ U I d d I C B I F U H B d B W U F E R B R D [ W V [ [ B R D C [ B W U D E C ^ S b S X � I K U B F D C [ U I d d D C G I [ U I C R I F RB d B W U F E R B � U H B B d B W U F E R B � [ F B [ D [ U I C W B C B B R C E U _ B J B I [ V F B R S @ E Q B ] B F � Q H B F B I C E C i [ U I C R I F R B d B W U F E R B D [D C [ U I d d B R � I F B [ D [ U I C W B J B I [ V F B J B C U [ H I d d _ B \ B F K E F J B R S 4 I F U H F B [ D [ U I C W B J B I [ V F B J B C U [ I F B V [ B K V d U E OI N ] B F D K Z U H B I R B c V I W Z E K I C B Q B I F U H D C G [ Z [ U B J ³_ N R B U B W U W H I C G B [ D C I C B M D [ U D C G B I F U H D C G [ Z [ U B J ³ I C RW N W H B W � E C R B [ D G C \ I F I J B U B F [ I C R W I d W V d I U D E C [ SNOTE:

p y n o � u � o r v u x � t y � � t o o u w y n o q � � � y o x � y n o y r y u t o v v o � y � � o w o � � � y u p � o x u � � o � u t � � t u y o q � � � p � y n o w o t u y � r p ¥-./01 2 1 3 4 56 6 6 6 65555 77777s n o w o | 8 9 8 : ; � � y n o y r y u t w o � � � y u p � o r v < p ² � u w u t t o t o t o � y w r q o � � u p q| = � � y n o w o � � � y u p � o r v o t o � y w r q o � �2 U [ H E V d R _ B C E U B R U H I U U H B B K K B W U D ] B F B [ D [ U I C W B E K I C B I F U H B d B W U F E R B U E B I F U H J I Z R B W F B I [ B _ Z V \ U E X f �I K U B F U H B K D F [ U b J E C U H [ U E a T J E C U H [ I K U B F D C [ U I d d I U D E C S > H D [ B K K B W U D [ d I F G B d Z R V B U E U H B [ B U U d D C G E K U H B [ E D dI F E V C R U H B B d B W U F E R B S. I d W V d I U D E C [ K E F U H B B I F U H F B [ D [ U I C W B E K I C B d B W U F E R B W E C K D G V F I U D E C J I � B U H B I [ [ V J \ U D E C E K H E J E G B C B E V [[ E D d H I ] D C G I W E C [ U I C U F B [ D [ U D ] D U Z S 2 C \ F I W U D W B � U H D [ I [ [ V J \ U D E C D [ F I F B d Z � D K B ] B F � K E V C R U E H E d R U F V B I C RW E C [ D R B F I _ d B R D [ W F B \ I C W D B [ W I C I F D [ B _ B U Q B B C I W I d W V d I U B R I C R J B I [ V F B R ] I d V B E K B I F U H F B [ D [ U I C W B S5.4.1 Methods of electrode resistance measurement 5 B \ B C R D C G E C U H B I \ \ d D W I U D E C � E C B E K U Q E J B U H E R [ E K B d B W U F E R B F B [ D [ U I C W B J B I [ V F B J B C U [ H I d d _ B V [ B R S 8U H D F R J B U H E R E K J B I [ V F B J B C U D [ V [ B R K E F ] B F D K D W I U D E C E K U H B J B I [ V F B R F B [ V d U [ S> H B J B U H E R � � C E Q C I [ U H B ¿ b a � e � F V d B À � D [ U H B [ D J \ d B [ U J B U H E R E K J B I [ V F B J B C U I C R D [ D R B I d K E F I \ \ d D W I U D E CU E F B d I U D ] B d Z [ J I d d B I F U H B d B W U F E R B [ Z [ U B J [ S ? U F D W U d Z [ \ B I � D C G � U H D [ J B U H E R F B c V D F B [ � C E Q d B R G B E K U H BB d B W U F D W I d W B C U F B E K U H B B d B W U F E R B U E _ B U B [ U B R S < C d B [ [ U H B B d B W U F E R B D [ [ Z J J B U F D W I d I _ E V U I G D ] B C \ E D C U � U H BB d B W U F D W I d W B C U F B J I Z C E U _ B B I [ D d Z K E V C R � J V W H d B [ [ I W W B [ [ B R S = B ] B F U H B d B [ [ � U H D [ J B U H E R H I [ I \ \ d D W I U D E CU E [ J I d d V C [ Z J J B U F D W I d B d B W U F E R B W E C K D G V F I U D E C [ S ; E F B M I J \ d B � U H D [ J B U H E R J I Z _ B V [ B R U E J B I [ V F B U H BF B [ D [ U I C W B E K I U H F B B \ E D C U [ U I F B I F U H B d B W U F E R B I U I U F I C [ K E F J B F D C [ U I d d I U D E C S8 \ I F U K F E J U H B D [ [ V B E K I W W B [ [ D C G U H B B d B W U F D W I d W B C U F B E K U H B B d B W U F E R B � U H B V [ B E K U H B b a � e � F V d B E C d I F G B[ Z [ U B J [ D [ d D J D U B R _ Z U H B d I F G B R D [ U I C W B [ F B c V D F B R K E F W V F F B C U D C � B W U D E C L [ B B ` S ^ S T S a U E ` S ^ S T S b N S2 U D [ F B W E J J B C R B R U H I U U H B F B [ V d U [ K F E J I F B [ D [ U I C W B J B I [ V F B J B C U _ Z U H B b a � e � J B U H E R I F B ] B F D K D B R _ Z U H B¿ K E V F \ E U B C U D I d J B U H E R À S > H D [ \ F E W B R V F B R E B [ C E U F B c V D F B U H I U J B I [ V F B J B C U [ I F B J I R B K F E J U H B B d B W U F D W I dW B C U F B E K U H B B d B W U F E R B U E _ B U B [ U B R S > H B R D [ I R ] I C U I G B E K F B c V D F D C G d I F G B R D [ U I C W B [ K E F W V F F B C U \ F E _ B[ \ I W D C G F B J I D C [ S> H B ¿ [ d E \ B J B U H E R À E K F B [ D [ U I C W B J B I [ V F B J B C U D [ J E F B I W W V F I U B U H I C U H B J B U H E R [ R B [ W F D _ B R I _ E ] B S 8 [U H B W V F F B C U \ F E _ B C B B R C E U _ B \ E [ D U D E C B R ] B F Z K I F K F E J U H B B d B W U F E R B � U H D [ J B U H E R D [ [ V D U I _ d B K E F V [ B E C d I F G BB d B W U F E R B [ Z [ U B J [ S > H D [ J B U H E R H I [ U H B I R ] I C U I G B U H I U D U [ V [ B R E B [ C E U R B \ B C R V \ E C U H B � C E Q d B R G B E KU H B d E W I U D E C E K U H B B I F U H [ Z [ U B J B d B W U F D W I d W B C U F B S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �33 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

5.4.2 The 61,8% method of earth electrode resistance measurement (with verification by the four potential method) 4 c V D \ J B C U W E C C B W U D E C [ K E F U H B b a � e � J B U H E R I F B D d d V [ U F I U B R D C ; D G V F B ^ S

> ? > @A ? A @B C D E F E B G E B DH IJ K L L M N OP L Q R MS I T U V WT U X WT U Y WT U Z WT U [ WT U I W \ ] ^ _ ` R K O a ^ b cP Q d e O e Q N d Q f O g M P Q O M N O e h i P L Q R M

M h L O g M i M J O L Q ` MK N ` M L O M d O jO k l m m n o p q r s r t l o ld p q u v m l o wxFigure 4 – Connections for the 61,8 % and four potential methods of earth electrode resistance

measurement> H B J B I [ V F B J B C U \ F E W B R V F B D [ I [ K E d d E Q [ O5.4.2.1

4 [ U I _ d D [ H U H B \ H Z [ D W I d d I Z E V U E K U H B B I F U H D C G [ Z [ U B J I C R U Z \ B E K B d B W U F E R B [ _ B D C G V [ B R � K E FB M I J \ d B D C U H B K D G V F B U H B B I F U H B d B W U F E R B D [ D C I U H F B B \ E D C U [ U I F W E C K D G V F I U D E C S5.4.2.2

5 D [ W E C C B W U U H B B I F U H B d B W U F E R B K F E J U H B B I F U H B R B c V D \ J B C U � \ F B K B F I _ d Z I U U H B \ E D C U Q H B F B U H B Q D F BK F E J U H B B c V D \ J B C U W E C C B W U [ U E U H B B I F U H B d B W U F E R B S 5 I C G B F [ I [ [ E W D I U B R Q D U H R D [ W E C C B W U D C G U H B B I F U HB d B W U F E R B [ H I d d _ B C E U B R I C R \ F B W I V U D E C I F Z J B I [ V F B [ [ H I d d _ B U I � B C Q H B C R D [ W E C C B W U D C G U H B B I F U HB d B W U F E R B S5.4.2.3

2 R B C U D K Z U H B \ E [ D U D E C E K U H B W V F F B C U \ F E _ B . T S > H B J B I [ V F B J B C U [ H I d d _ B U I � B C I Q I Z K F E J U H B d D C BE K I C Z � C E Q C U F B C W H B I F U H � J B U I d d D W \ D \ B E F V C R B F G F E V C R W I _ d B [ S > H B R D [ U I C W B _ B U Q B B C U H B B d B W U F E R B V C R B FU B [ U I C R U H B W V F F B C U \ F E _ B . T [ H I d d _ B K D ] B U D J B [ U H B d B C G U H E K U H B d E C G B [ U B I F U H F E R � d E C G B [ U H E F D � E C U I dd B C G U H E F U H B d E C G B [ U R D I G E C I d E K U H B B I F U H D C G [ Z [ U B J _ V U C E U d B [ [ U H I C ` f J S ; E F [ U I C R I F R D � I U D E C \ V F \ E [ B [D U D [ \ F E \ E [ B R U H I U I R D [ U I C W B E K a f f J _ B V [ B R S5.4.2.4

? B U U H B \ E U B C U D I d \ F E _ B 1 T D C d D C B Q D U H U H B U B [ U B R B d B W U F E R B I C R U H B W V F F B C U \ F E _ B . T I U I R D [ U I C W BB c V I d U E f � b a e E K U H B R D [ U I C W B U E U H B W V F F B C U \ F E _ B S � I U B F U H B I F B I I F E V C R U H B W V F F B C U \ F E _ B . T U E F B R V W BD U [ F B [ D [ U I C W B S @ D G H \ F E _ B F B [ D [ U I C W B F B R V W B [ U H B I J E V C U E K W V F F B C U U H I U U H B U B [ U [ B U W I C D C � B W U D C U E U H B [ E D d S5.4.2.5

. E C C B W U U H B B I F U H U B [ U B F U B F J D C I d [ . a I C R 1 a U E U H B U B [ U B R B d B W U F E R B � U B F J D C I d 1 T U E U H B \ E U B C U D I d\ F E _ B [ 1 T I C R U H B U B F J D C I d . T U E U H B W V F F B C U \ F E _ B . T S / \ B F I U B U H B B I F U H U B [ U B F I C R E _ U I D C U H B F B [ D [ U I C W BF B I R D C G S 6 Z U H B b a � e � J B U H E R � U H D [ F B I R D C G D [ U H B F B [ D [ U I C W B E K U H B B d B W U F E R B V C R B F U B [ U S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �34 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

5.4.2.6 > H B F B [ V d U E _ U I D C B R D C ` S ^ S T S b [ H I d d _ B ] B F D K D B R V [ D C G U H B K E d d E Q D C G \ F E W B R V F B L � C E Q C I [ U H B K E V F\ E U B C U D I d J B U H E R N OI N Q D U H U H B W V F F B C U \ F E _ B [ [ B U V \ I [ _ B K E F B � J B I [ V F B U H B F B [ D [ U I C W B Q D U H U H B \ E U B C U D I d B d B W U F E R B 1 T[ B U V \ I U U H B R D [ U I C W B [ O f � T ³ f � ^ ³ f � ` ³ f � b ³ f � g ³ I C R f � e E K U H B R D [ U I C W B U E U H B W V F F B C U B d B W U F E R B ³_ N U H B ] I d V B [ E _ U I D C B R _ Z J B I [ V F B J B C U I U U H B [ D M \ E [ D U D E C [ L R B [ D G C I U B R 9 y U E 9 z N [ H I d d _ B U I _ V d I U B R S> H B K E F J I U K E F U H D [ U I _ d B D [ G D ] B C D C U I _ d B e S

Table 8 – Results table format for the 61,8 % and four potential method of electrode resistance measurement � ¼ »

Definition Position Distance ´ ö ¶ Measured resistance ´ ¶{ � � ô � � � � � � ô � ñ ë � õ � { � � � � ô � ñ ë � õ » {

� | � � ô � ñ ë � õ º { � } � � ô � ñ ë � õ ½ { ò � ë ñ é � � � � ë ñ � ê � � ô � ñ ë � õ ½ � { � ~ � � ô � ñ ë � õ ¹ { � � � � ô � ñ ë � õ � { W N K E V F ] I d V B [ K E F B d B W U F E R B F B [ D [ U I C W B I F B R B F D ] B R K F E J U H B K E V F \ E U B C U D I d J B U H E R I W W E F R D C G U E U H BK E F J V d I [ Oa N 9 ) f � a a e g 9 y f � ^ b b g 9 � � a � h e a b 9 � f � X h b a 9 zT N 9 ) T � b a f e 9 � � ^ � f ` f e 9 � f � a b T b 9 � f � T g g ^ 9 zX N 9 ) a � e e g a 9 � � a � a a ^ e 9 � � X � b e X g 9 � a � h a a ^ 9 �^ N 9 ) b � ` T T ` 9 � � a X � b e a b 9 � b � e e f X 9 � � f � g T a f 9 zR N U H B K E V F ] I d V B [ E K 9 � E _ U I D C B R K F E J L W N � [ H I d d I G F B B [ V _ [ U I C U D I d d Z I C R I C I ] B F I G B E K U H B F B [ V d U [J I Z U H B C _ B W I d W V d I U B R S @ E Q B ] B F � D U D [ \ E [ [ D _ d B U H I U U H B F B [ V d U K F E J B c V I U D E C L a N Q D d d _ B d B [ [I W W V F I U B U H I C U H B E U H B F [ S 2 K U H B F B [ V d U E K L a N R E B [ \ F E ] B U E _ B I U ] I F D I C W B Q D U H U H B E U H B F [ D U W I C _ BD G C E F B R I C R I C I ] B F I G B E _ U I D C B R K F E J U H B U H F B B J E F B I G F B B I _ d B ] I d V B [ S

5.4.3 The slope method of earth electrode resistance measurement 4 c V D \ J B C U W E C C B W U D E C [ K E F U H B [ d E \ B J B U H E R I F B D d d V [ U F I U B R D C K D G V F B ` S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �35 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

� � � �� � � �� � � � � � � � � � �

� � � � � � � � � � � � � � � � � � � � � � � � � �� � � � � � � � �� � � � � � �   �  ¡ ¢ £ ¢ ¤ � � � � ¢ ¥ � � � � � �   � ¦§ � � � � ¢� � � ¨� �

Figure 5 – Connections for the slope method of earth electrode resistance measurement > H B J B I [ V F B J B C U \ F E W B R V F B D [ I [ K E d d E Q [ O5.4.3.1

> H B W V F F B C U \ F E _ B . T D [ \ d I W B R I R D [ U I C W B R W K F E J U H B \ E D C U E K W V F F B C U D C � B W U D E C I U U H B B I F U HB d B W U F E R B U E _ B U B [ U B R S > H B R D [ U I C W B R W J V [ U _ B G F B I U B F U H I C ` f J S5.4.3.2

> H B \ E U B C U D I d \ F E _ B D [ \ d I W B R D C d D C B Q D U H U H B W V F F B C U \ F E _ B I C R B I F U H B d B W U F E R B D C B I W H E K U H F B B\ E [ D U D E C [ S 5 D [ U I C W B [ K F E J U H B B I F U H B d B W U F E R B E K f � T ³ f � ^ ³ I C R f � b U D J B [ U H B R D [ U I C W B R W I F B U E _ B V [ B R S5.4.3.3

> H B B I F U H U B [ U B F U B F J D C I d [ . a I C R 1 a I F B W E C C B W U B R U E U H B B I F U H B d B W U F E R B S > H B W V F F B C U \ F E _ B D [W E C C B W U B R U E U B F J D C I d . T E K U H B U B [ U B F S > H B \ E U B C U D I d \ F E _ B D [ W E C C B W U B R U E U B F J D C I d 1 T S5.4.3.4

; E F B I W H \ E [ D U D E C E K \ E U B C U D I d \ F E _ B O f � T R W ³ f � ^ R W ³ I C R f � b R W ³ U H B B I F U H U B [ U B F D [ E \ B F I U B R I C RF B [ D [ U I C W B ] I d V B [ 9 a � 9 T I C R 9 X I F B E _ U I D C B R F B [ \ B W U D ] B d Z S5.4.3.5

> H B [ d E \ B W E B K K D W D B C U � � D [ W I d W V d I U B R I W W E F R D C G U E U H B J B I [ V F B R F B [ D [ U I C W B ] I d V B [ V [ D C G U H BK E F J V d I O ©� �ª 77 775.4.3.6

8 ] I d V B K E F U H B U B F J R 1 > k R W W E F F B [ \ E C R D C G U E U H B W I d W V d I U B R ] I d V B D [ F B I R K F E J U I _ d B h S 2 K U H BW I d W V d I U B R ] I d V B E K « K I d d [ E V U [ D R B U H E [ B G D ] B C D C U H B U I _ d B � D U Q D d d _ B C B W B [ [ I F Z U E J E ] B U H B W V F F B C U \ F E _ BK V F U H B F I Q I Z K F E J U H B B I F U H D C G [ Z [ U B J I C R F B \ B I U U H B U B [ U [ SNOTE: � n o p � x � o w � � p y n o v � w � y w r s r v y u � t o £ w o � w o � o p y y n o y n � w q q o � � x u t r v y n o � u t � o � p y n o v � w � y � r t � x p � ª r w o ¾ u x � t o � y n oq ¬ ­ � q ® � u t � o � r w w o � � r p q � p � y r ¯ ­ � � ­   � � ­ � � � � ® �

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �36 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Table 9 – Table of values of dPT/dc for values of

0 1 2 3 4 5 6 7 8 9 � õ » � � õ ½ » ¼ � � õ ½ » ¼ � õ ½ » � ø � õ ½ » � � � õ ½ » � ½ � õ ½ » � º � õ ½ » � ¼ � õ ½ » � � � õ ½ » � � � õ ½ » ø� õ » � õ ½ » � � õ ½ » ½ � õ ½ » º � õ ½ » ¼ � õ ½ » � � õ ½ » � � õ ½ » � ø � õ ½ » � � � õ ½ » � ½ � õ ½ » � º� õ » � � õ ½ » � ¼ � õ ½ » � � � õ ½ » � � � õ ½ ¼ ø ø � õ ½ » ¼ ¹ � õ ½ ¼ ø ½ � õ ½ ¼ ø º � õ ½ ¼ ø ¼ � õ ½ ¼ ø � � õ ½ ¼ ø �� õ » ¼ � õ ½ ¼ � ø � õ ½ ¼ � ¹ � õ ½ ¼ � ½ � õ ½ ¼ � » � õ ½ ¼ � ¼ � õ ½ ¼ � � � õ ½ ¼ � � � õ ½ ¼ ¹ ø � õ ½ ¼ ¹ ¹ � õ ½ ¼ ¹ ½� õ » » � õ ½ ¼ ¹ » � õ ½ ¼ ¹ ¼ � õ ½ ¼ ¹ � � õ ½ ¼ ¹ � � õ ½ ¼ ½ ø � õ ½ ¼ ½ ¹ � õ ½ ¼ ½ ½ � õ ½ ¼ ½ » � õ ½ ¼ ½ ¼ � õ ½ ¼ ½ � õ » º � õ ½ ¼ ½ � � õ ½ ¼ º ø � õ ½ ¼ º ¹ � õ ½ ¼ º ½ � õ ½ ¼ º » � õ ½ ¼ º ¼ � õ ½ ¼ º � õ ½ ¼ º � � õ ½ ¼ » � � õ ½ ¼ » ¹� õ » ½ � õ ½ ¼ » ½ � õ ½ ¼ » » � õ ½ » » ¼ � õ ½ ¼ » � õ ½ ¼ » � � õ ½ ¼ ¼ � � õ ½ ¼ ¼ ¹ � õ ½ ¼ ¼ ½ � õ ½ ¼ ¼ » � õ ½ ¼ ¼ ¼� õ » ¹ � õ ½ ¼ ¼ � õ ½ ¼ ¼ � � õ ½ ¼ � � � õ ½ ¼ � ¹ � õ ½ ¼ � º � õ ½ ¼ � » � õ ½ ¼ � ¼ � õ ½ ¼ � � õ ½ ¼ � � � õ ½ ¼ �� õ » � � õ ½ ¼ ¹ � õ ½ ¼ º � õ ½ ¼ » � õ ½ ¼ � � õ ½ ¼ � õ ½ ¼ � � õ ½ ¼ � � � õ ½ ¼ � ¹ � õ ½ ¼ � º � õ ½ ¼ � »� õ » ø � õ ½ ¼ � � � õ ½ ¼ � � õ ½ ¼ � � � õ ½ � ø � � õ ½ � ø ¹ � õ ½ � ø º � õ ½ � ø » � õ ½ � ø � � õ ½ � ø � õ ½ � � ø� õ º � � õ ½ � � � � õ ½ � � ½ � õ ½ � � º � õ ½ � � ¼ � õ ½ � � � � õ ½ � � � � õ ½ � ¹ ø � õ ½ � ¹ ¹ � õ ½ � ¹ ½ � õ ½ � ¹ »� õ º � õ ½ � ¹ ¼ � õ ½ � ¹ � õ ½ � ¹ � � õ ½ � ½ � � õ ½ � ½ ¹ � õ ½ � ½ º � õ ½ � ½ » � õ ½ � ½ � � õ ½ � ½ � õ ½ � º ø� õ º � � õ ½ � º � � õ ½ � º ½ � õ ½ � º º � õ ½ � º ¼ � õ ½ � º � � õ ½ � º � � õ ½ � » � � õ ½ ¼ » ¹ � õ ½ � » º � õ ½ � » »� õ º ¼ � õ ½ � » � � õ ½ � » � õ ½ � ¼ ø � õ ½ � ¼ � � õ ½ � ¼ ½ � õ ½ � ¼ º � õ ½ � ¼ ¼ � õ ½ � ¼ � � õ ½ � ¼ � � õ ½ � � ø� õ º » � õ ½ � � ¹ � õ ½ � � ½ � õ ½ � � » � õ ½ � � ¼ � õ ½ � � � õ ½ � � � � õ ½ � � � õ ½ � ¹ � õ ½ � º � õ ½ � »� õ º º � õ ½ � � � õ ½ � � � õ ½ � � ø � õ ½ � � ¹ � õ ½ � � ½ � õ ½ � � » � õ ½ � � ¼ � õ ½ � � � õ ½ � � � � õ ½ ø �� õ º ½ � õ ½ ø ¹ � õ ½ ø º � õ ½ ø » � õ ½ ø � � õ ½ ø � õ ½ � ø � õ ½ � � � õ ½ � ½ � õ ½ � º � õ ½ � ¼� õ º ¹ � õ ½ � � � õ ½ � � � õ ½ ¹ ø � õ ½ ¹ ¹ � õ ½ ¹ ½ � õ ½ ¹ » � õ ½ ¹ � � õ ½ ¹ � õ ½ ½ ø � õ ½ ½ �� õ º � � õ ½ ½ ½ � õ ½ ½ º � õ ½ ½ ¼ � õ ½ ½ � � õ ½ ½ � � õ ½ º ø � õ ½ º ¹ � õ ½ º ½ � õ ½ º » � õ ½ º ¼� õ º ø � õ ½ º � õ ½ º � � õ ½ » � � õ ½ » ¹ � õ ½ » º � õ ½ » » � õ ½ » � � õ ½ » � õ ½ ¼ ø � õ ½ ¼ �� õ ½ � � õ ½ ¼ ½ � õ ½ ¼ » � õ ½ ¼ ¼ � õ º ¼ � õ ½ ¼ � � õ ½ � � � õ ½ � ½ � õ ½ � º � õ ½ � ¼ � õ ½ � � õ ½ � õ ½ � � � õ ½ � � õ ½ ¹ � õ ½ º � õ ½ ¼ � õ ½ � � õ ½ � � õ ½ � � � õ ½ � ¹ � õ ½ � º� õ ½ � � õ ½ � » � õ ½ � � � õ ½ � � � õ ½ � ø ø � õ ½ � ø ¹ � õ ½ � ø ½ � õ ½ � ø » � õ ½ � ø � � õ ½ � ø � õ ½ � � ø� õ ½ ¼ � õ ½ � � ¹ � õ ½ � � ½ � õ ½ � � » � õ ½ � � ¼ � õ ½ � � � õ ½ � ¹ ø � õ ½ � ¹ ½ � õ ½ � ¹ ½ � õ ½ � ¹ » � õ ½ � ¹ ¼� õ ½ » � õ ½ � ¹ � õ ½ � ¹ � � õ ½ � ½ � � õ ½ � ½ ½ � õ ½ � ½ º � õ ½ � ½ ¼ � õ ½ � ½ � õ ½ � ½ � � õ ½ � º � � õ ½ � º ¹� õ ½ º � õ ½ � º º � õ ½ � º ¼ � õ ½ � º � � õ ½ � º � � õ ½ � » ø � õ ½ � » ¹ � õ ½ � » º � õ ½ � » » � õ ½ � » � � õ ½ � » �� õ ½ ½ � õ ½ � ¼ ø � õ ½ � ¼ ¹ � õ ½ � ¼ ½ � õ ½ � ¼ » � õ ½ � ¼ � � õ ½ � ¼ � õ ½ � � ø � õ ½ � � ¹ � õ ½ � � ½ � õ ½ � � »� õ ½ ¹ � õ ½ � � ¼ � õ ½ � � � õ ½ � ø � õ ½ � � � õ ½ � ½ � õ ½ � º � õ ½ � ¼ � õ ½ � � õ ½ � � � õ ½ � � �� õ ½ � � õ ½ � � ½ � õ ½ � � º � õ ½ � � ¼ � õ ½ � � � � õ ½ � � � � õ º ø ø � � õ º ø ø ¹ � õ º ø ø º � õ º ø ø ¼ � õ º ø ø �� õ ½ ø � õ º ø ø � � õ º ø � ø � õ º ø � ¹ � õ º ø � º � õ º ø � » � õ º ø � � � õ º ø � � � õ º ø ¹ ø � õ º ø ¹ ¹ � õ º ø ¹ ½� õ ¹ � � õ º ø ¹ » � õ º ø ¹ ¼ � õ º ø ¹ � õ º ø ½ ø � õ º ø ½ ¹ � õ º ø ½ º � õ º ø ½ » � õ º ø ½ � � õ º ø ½ � � õ º ø º ø� õ ¹ � õ º ø º ¹ � õ º ø º º � õ º ø º ¼ � õ º ø º � � õ º ø º � � õ º ø » � � õ º ø » ¹ � õ º ø » º � õ º ø » ¼ � õ º ø » �� õ ¹ � � õ º ø » � � õ º ø ¼ � � õ º ø ¼ ½ � õ º ø ¼ º � õ º ø ¼ ¼ � õ º ø ¼ � õ º ø ¼ � � õ º ø � � � õ º ø � ½ � õ º ø � »

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �37 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

� õ ¹ ¼ � õ º ø � ¼ � õ º ø � � õ º ø � � � õ º ø � � õ º ø ½ � õ º ø » � õ º ø � � õ º ø � õ º ø � ø � õ º ø � ¹� õ ¹ » � õ º ø � ½ � õ º ø � » � õ º ø � � � õ º ø � � � õ º � ø ø � õ º � ø ¹ � õ º � ø º � õ º � ø » � õ º � ø � � õ º � ø �� õ ¹ º � õ º � � ø � õ º � � ¹ � õ º � � º � õ º � � ¼ � õ º � � � � õ º � � � � õ º � ¹ � � õ º � ¹ ¹ � õ º � ¹ º � õ º � ¹ ¼� õ ¹ ½ � õ º � ¹ � õ º � ¹ � � õ º � ½ � � õ º � ½ ½ � õ º � ½ º � õ º � ½ ¼ � õ º � ½ � õ º � º ø � õ º � º � � õ º � º ½� õ ¹ ¹ � õ º � º » � õ º � º ¼ � õ º � º � õ º � ¼ ø � õ º � » ¹ � õ º � » ½ � õ º � » » � õ º � » � � õ º � » � õ º � ¼ ø� õ ¹ � � õ º � ¼ ¹ � õ º � ¼ º � õ º � ¼ » � õ º � ¼ � � õ º � ¼ � � õ º � � ø � õ º � � ¹ � õ º � � º � õ º � � » � õ º � � �� õ ¹ ø � õ º � � � � õ º � � � õ º � ¹ � õ º � º � õ º � ¼ � õ º � � � õ º � � � õ º � � � � õ º � � ½ � õ º � � º� õ � � � õ º � � ¼ � õ º � � � õ º ¹ ø ø � õ º ¹ ø ¹ � õ º ¹ ø ½ � õ º ¹ ø » � õ º ¹ ø � � õ º ¹ ø � � õ º ¹ � � � õ º ¹ � ½� õ � � õ º ¹ � º � õ º ¹ � ¼ � õ º ¹ � � õ º ¹ ¹ ø � õ º ¹ ¹ ¹ � õ º ¹ ¹ º � õ º ¹ ¹ ¼ � õ º ¹ ¹ � � õ º ¹ ¹ � � õ º ¹ ½ �� õ � � � õ º ¹ ½ ½ � õ º ¹ ½ » � õ º ¹ ½ � � õ º ¹ ½ � � õ º ¹ º ø � õ º ¹ º ¹ � õ º ¹ º º � õ º ¹ º ¼ � õ º ¹ º � õ º ¹ » ø� õ � ¼ � õ º ¹ » � � õ º ¹ » ½ � õ º ¹ » » � õ º ¹ » � � õ º ¹ » � � õ º ¹ ¼ � � õ º ¹ ¼ ½ � õ º ¹ ¼ º � õ º ¹ ¼ ¼ � õ º ¹ ¼ � õ � » � õ º ¹ � ø � õ º ¹ � ¹ � õ º ¹ � º � õ º ¹ � ¼ � õ º ¹ � � � õ º ¹ � � � õ º ¹ � � õ º ¹ ½ � õ º ¹ » � õ º ¹ �� õ � º � õ º ¹ � õ º ¹ � ø � õ º ¹ � ¹ � õ º ¹ � º � õ º ¹ � ¼ � õ º ¹ � � õ º ½ ø ø � õ º ½ ø � � õ º ½ ø ½ � õ º ½ ø »� õ � ½ � õ º ½ ø � � õ º ½ ø � � õ º ½ � � � õ º ½ � ½ � õ º ½ � º � õ º ½ � ¼ � õ º ½ � � õ º ½ ¹ ø � õ º ½ ¹ ¹ � õ º ½ ¹ º� õ � ¹ � õ º ½ ¹ » � õ º ½ ¹ � � õ º ½ ¹ � � õ º ½ ½ � � õ º ½ ½ ½ � õ º ½ ½ » � õ º ½ ½ � � õ º ½ ½ � õ º ½ º ø � õ º ½ º ¹� õ � � � õ º ½ º º � õ º ½ º ¼ � õ º ½ º � õ º ½ º � � õ º ½ » � � õ º ½ » ½ � õ º ½ » » � õ º ½ » � � õ º ½ » � � õ º ½ ¼ �� õ � ø � õ º ½ ¼ ¹ � õ º ½ ¼ º � õ º ½ ¼ ¼ � õ º ½ ¼ � õ º ½ � ø � õ º ½ � ¹ � õ º ½ � º � õ º ½ � » � õ º ½ � � � õ º ½ � �� õ ø � � õ º ½ � � õ º ½ ½ � õ º ½ » � õ º ½ � � õ º ½ � � õ º ½ � � � õ º ½ � ½ � õ º ½ � » � õ º ½ � � � õ º ½ � �� õ ø � õ º º ø � � õ º º ø ½ � õ º º ø » � õ º º ø � � õ º º ø � � õ º º � � � õ º º � ½ � õ º º � » � õ º º � � � õ º º � �� õ ø � � õ º º ¹ � � õ º º ¹ ½ � õ º º ¹ » � õ º º ¹ � � õ º º ¹ � � õ º º ½ � � õ º º ½ º � õ º º ½ ¼ � õ º º ½ � õ º º º ø� õ ø ¼ � õ º º º ¹ � õ º º º º � õ º º º ¼ � õ º º º � õ º º » ø � õ º º » ¹ � õ º º » º � õ º º » ¼ � õ º º » � õ º º ¼ ø� õ ø » � õ º º ¼ ¹ � õ º º ¼ º � õ º º ¼ ¼ � õ º º ¼ � õ º º � ø � õ º º � ¹ � õ º º � º � õ º º � ¼ � õ º º � � õ º º ø� õ ø º � õ º º ¹ � õ º º º � õ º º ¼ � õ º º � õ º º � ø � õ º º � � � õ º º � º � õ º º � ¼ � õ º º � � õ º » ø ø� õ ø ½ � õ º » ø ¹ � õ º » ø º � õ º » ø ¼ � õ º » ø � õ º » � ø � õ º » � ¹ � õ º » � º � õ º » � ¼ � õ º » � � õ º » ¹ ø� õ ø ¹ � õ º » ¹ ¹ � õ º » ¹ º � õ º » ¹ ¼ � õ º » ¹ � õ º » ½ ø � õ º » ½ ¹ � õ º » ½ » � õ º » ½ � � õ º » ½ � � õ º » º �� õ ø � � õ º » º ½ � õ º » º » � õ º » º � � õ º » º � � õ º » » � � õ º » » ½ � õ º » » » � õ º » » � � õ º » » � � õ º » ¼ �� õ ø ø � õ º » ¼ ½ � õ º » ¼ » � õ º ¼ » � � õ º » ¼ � � õ º » � � � õ º » � ½ � õ º » � » � õ º » � � � õ º » � � � õ º » � õ � � � õ º » � ½ � õ º » » � õ º » � � õ º » � ø � õ º » � ¹ � õ º » � º � õ º » � ¼ � õ º » � � � õ º ¼ ø � � õ º ¼ ø ½ õ � � õ º ¼ ø » � õ º ¼ ø � õ º ¼ � ø � õ º ¼ � ¹ � õ º ¼ � º � õ º ¼ � ¼ � õ º ¼ � � � õ º ¼ ¹ � � õ º ¼ ¹ ½ � õ º ¼ ¹ » õ � � � õ º ¼ ¹ � õ º ¼ ½ ø � õ º ¼ ½ ¹ � õ º ¼ ½ º � õ º ¼ ½ � � õ º ¼ ½ � � õ º ¼ º � � õ º ¼ º ½ � õ º ¼ º » � õ º ¼ º õ � ¼ � õ º ¼ » ø � õ º ¼ » ¹ � õ º ¼ » º � õ º ¼ » » � õ º ¼ » � � õ º ¼ ¼ � � õ º ¼ ¼ ½ � õ º ¼ ¼ ¼ � õ º ¼ ¼ � õ º ¼ � ø õ � » � õ º ¼ � ¹ � õ º ¼ � º � õ º ¼ � � � õ º ¼ � � � õ º ¼ � � õ º ¼ ½ � õ º ¼ ¼ � õ º ¼ � õ º ¼ � ø � õ º ¼ � ¹ õ � º � õ º ¼ � º � õ º ¼ � � � õ º ¼ � � � õ º � ø � � õ º � ø ½ � õ º � ø ¼ � õ º � ø � õ º � � ø � õ º � � ¹ � õ º � � » õ � ½ � õ º � � � � õ º � � � � õ º � ¹ � � õ º � ¹ ½ � õ º � ¹ ¼ � õ º � ¹ � õ º � ½ ø � õ º � ½ ¹ � õ º � ½ » � õ º � ½ � õ � ¹ � õ º � ½ � � õ º � º � � õ º � º º � õ º � º ¼ � õ º � º � õ º � » ø � õ º � » ¹ � õ º � » » � õ º � » � � õ º � » �

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �38 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

õ � � � õ º � ¼ � � õ º � ¼ º � õ º � ¼ ¼ � õ º � ¼ � õ º � � ø � õ º � � ø � õ º � � » � õ º � � � � õ º � ø � õ º � ¹ õ � ø � õ º � º � õ º � ¼ � õ º � � õ º � � ø � õ º � � ½ � õ º � � » � õ º � � � � õ º � � � � õ º ø ¹ � õ º ø º õ � � õ º ø ¼ � õ º ø � � õ º � � � õ º � º � õ º � ¼ � õ º � ø � õ º ¹ � � õ º ¹ º � õ º ¹ ¼ � õ º ¹ � õ � õ º ½ � � õ º ½ º � õ º ½ ¼ � õ º ½ � � õ º º � � õ º º º � õ º º ¼ � õ º º � � õ º » � � õ º » º õ � � õ º » ¼ � õ º » � � õ º ¼ ¹ � õ º ¼ º � õ º ¼ � � õ º ¼ � � õ º � ¹ � õ º � º � õ º � � � õ º � � õ ¼ � õ º � � õ º º � õ º ¼ � õ º � � õ º � � � õ º � º � õ º � � ¼ � õ º � � � õ º � ø � � õ º � ø º õ » � õ º � ø ¼ � õ º � ø � � õ º � � � � õ º � � º � õ º � � ¼ � õ º � � � � õ º � ¹ � � õ º � ¹ º � õ º � ¹ ¼ � õ º � ¹ � õ º � õ º � ½ � � õ º � ½ º � õ º � ½ � � õ º � ½ � � õ º � º ¹ � õ º � º º � õ º � º � � õ º � º � � õ º � » ¹ � õ º � » º õ ½ � õ º � » � � õ º � » � � õ º � ¼ ¹ � õ º � ¼ º � õ º � ¼ � � õ º � ¼ � � õ º � � ¹ � õ º � � º � õ º � � � � õ º � � � õ ¹ � õ º � ¹ � õ º � º � õ º � � � õ º � � � õ º � � ¹ � õ º � � º � õ º � � � � õ º � � � � õ » ø ø ¹ � õ » ø ø º õ � � õ » ø ø � � õ » ø ø � � õ » ø � ¹ � õ » ø � º � õ » ø � � � õ » ø � � � õ » ø ¹ ¹ � õ » ø ¹ º � õ » ø ¹ � � õ » ø ¹ � õ ø � õ » ø ½ ¹ � õ » ø ½ º � õ » ø ½ � � õ » ø ½ � � õ » ø º ¹ � õ » ø º º � õ » ø º � � õ » ø º � � õ » ø » ¹ � õ » ø » º õ � � � õ » ø » � � õ » ø ¼ ø � õ » ø ¼ ½ � õ » ø ¼ ¼ � õ » ø ¼ � � õ » ø � � � õ » ø � º � õ » ø � � � õ » ø ø � õ » ø ½ õ � � õ » ø ¼ � õ » ø � � õ » ø � ¹ � õ » ø � » � õ » ø � � õ » � ø ø � õ » � ø ½ � õ » � ø ¼ � õ » � ø � � õ » � � ¹ õ � � � õ » � � » � õ » � � � õ » � ¹ � � õ » � ¹ º � õ » � ¹ � � õ » � ¹ � � õ » � ½ ¹ � õ » � ½ » � õ » � ½ � õ » � º � õ � ¼ � õ » � º º � õ » � º � � õ » � » ø � õ » � » ½ � õ » � » ¼ � õ » � » � õ » � ¼ � � õ » � ¼ º � õ » � ¼ � � õ » � � ø õ � » � õ » � � ½ � õ » � � ¼ � õ » � � � � õ » � ¹ � õ » � » � õ » � � � õ » � � ø � õ » � � ½ � õ » � � ¼ � õ » � � � õ � º � õ » ¹ ø ¹ � õ » ¹ ø » � õ » ¹ ø � õ » ¹ � � � õ » ¹ � º � õ » ¹ � ¼ � õ » ¹ � � � õ » ¹ ¹ ¹ � õ » ¹ ¹ » � õ » ¹ ¹ õ � ½ � õ » ¹ ½ � � õ » ¹ ½ º � õ » ¹ ½ � � õ » ¹ º ø � õ » ¹ º ½ � õ » ¹ º » � õ » ¹ º � õ » ¹ » � � õ » ¹ » º � õ » ¹ » � õ � ¹ � õ » ¹ ¼ ø � õ » ¹ ¼ ½ � õ » ¹ ¼ ¼ � õ » ¹ ¼ � � õ » ¹ � ¹ � õ » ¹ � º � õ » ¹ � � � õ » ¹ ø � õ » ¹ ½ � õ » ¹ ¼ õ � � � õ » ¹ � � õ » ¹ � ¹ � õ » ¹ � » � õ » ¹ � � õ » ½ ø � � õ » ½ ø ½ � õ » ½ ø ¼ � õ » ½ ø � � õ » ½ � ¹ � õ » ½ � » õ � ø � õ » ½ � � õ » ½ ¹ � � õ » ½ ¹ º � õ » ½ ¹ � � õ » ½ ½ ø � õ » ½ ½ ¹ � õ » ½ ½ » � õ » ½ ½ � õ » ½ º � � õ » ½ º º õ ¼ � � õ » ½ º � � õ » ½ » ø � õ » ½ » º � õ » ½ » � � õ » ½ ¼ � � õ » ½ ¼ º � õ » ½ ¼ � õ » ½ � � � õ » ½ � º � õ » ½ � õ ¼ � õ » ½ � � õ » ½ ½ � õ » ½ � õ » ½ � ¹ � õ » ½ � » � õ » ½ � � õ » º ø ¹ � õ » º ø » � õ » º ø � � õ » º � ½ õ ¼ � � õ » º � ¼ � õ » º � � � õ » º ¹ ¹ � õ » º ¹ ¼ � õ » º ¹ � � õ » º ½ ½ � õ » º ½ ¼ � õ » º º ø � õ » º º ½ � õ » º º ¼ õ ¼ ¼ � õ » º » ø � õ » º » ½ � õ » º » � � õ » º ¼ ø � õ » º ¼ º � õ » º ¼ � � õ » º � ø � õ » º � º � õ » º � � � õ » º � õ ¼ » � õ » º º � õ » º � õ » º � � � õ » º � º � õ » º � � õ » » ø � � õ » » ø » � õ » » ø � õ » » � ¹ � õ » » � » õ ¼ º � õ » » � � õ » » ¹ ¹ � õ » » ¹ » � õ » » ¹ � � õ » » ½ ¹ � õ » » ½ ¼ � õ » » ½ � � õ » » º ¹ � õ » » º ¼ � õ » » º � õ ¼ ½ � õ » » » ½ � õ » » » ¼ � õ » » ¼ ø � õ » » ¼ ½ � õ » » ¼ � � õ » » � ø � õ » » � ½ � õ » » � � � õ » » ø � õ » » º õ ¼ ¹ � õ » » � � õ » » � � � õ » » � º � õ » » � � � õ » ¼ ø � � õ » ¼ ø º � õ » ¼ ø � õ » ¼ � � � õ » ¼ � » � õ » ¼ � õ ¼ � � õ » ¼ ¹ � � õ » ¼ ¹ » � õ » ¼ ¹ � õ » ¼ ½ ¹ � õ » ¼ ½ » � õ » ¼ ½ � � õ » ¼ º ¹ � õ » ¼ º » � õ » ¼ º � � õ » ¼ » ¹ õ ¼ ø � õ » ¼ » ¼ � õ » ¼ » � � õ » ¼ ¼ ½ � õ » ¼ ¼ ¼ � õ º ¼ ¼ � � õ » ¼ � ½ � õ » ¼ � ¼ � õ » ¼ ø � õ » ¼ ½ � õ » ¼ �

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �39 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Table 9 – (concluded)

0 1 2 3 4 5 6 7 8 9 õ » � � õ » ¼ � ø � õ » ¼ � º � õ » ¼ � � õ » � ø ½ � õ » � ø � � õ » � � � � õ » � � » � õ » � � � � õ » � ¹ º � õ » � ¹ õ » � õ » � ½ ¹ � õ » � ½ ¼ � õ » � º � � õ » � º » � õ » � º � � õ » � » ½ � õ » � » � � õ » � ¼ ¹ � õ » � ¼ ¼ � õ » � � ø õ » � � õ » � � º � õ » � � � õ » � ½ � õ » � � � õ » � � � � õ » � � » � õ » � � � � õ » ø º � õ » ø � õ » � ¹ õ » ¼ � õ » � ¼ � õ » ¹ � � õ » ¹ » � õ » ¹ � � õ » ½ ½ � õ » ½ � � õ » º ¹ � õ » º ¼ � õ » » ø � õ » » º õ » » � õ » » � õ » ¼ ½ � õ º ¼ � � õ » � � � õ » � » � õ » � � � õ » º � õ » � õ » � ¹ � õ » � ¼ õ » º � õ » � ø ø � õ » � ø » � õ » � ø � � õ » � � ½ � õ » � � � � õ » � ¹ ¹ � õ » � ¹ ¼ � õ » � ½ ø � õ » � ½ º � õ » � ½ õ » ½ � õ » � º ½ � õ » � º � � õ » � » � � õ » � » » � õ » � » � � õ » � ¼ º � õ » � ¼ � õ » � � ¹ � õ » � � ¼ � õ » � � õ » ¹ � õ » � » � õ » � � � õ » � � º � õ » � � � õ ¼ ø ø ¹ � õ ¼ ø ø ¼ � õ ¼ ø � ø � õ ¼ ø � º � õ ¼ ø � � � õ ¼ ø ¹ ½ õ » � � õ ¼ ø ¹ � � õ ¼ ø ½ � � õ ¼ ø ½ » � õ ¼ ø º ø � õ ¼ ø º º � õ ¼ ø º � õ ¼ ø » ¹ � õ ¼ ø » ¼ � õ ¼ ø ¼ � � õ ¼ ø ¼ » õ » ø � õ ¼ ø ¼ � � õ ¼ ø � ½ � õ ¼ ø � � õ ¼ ø ¹ � õ ¼ ø ¼ � õ ¼ ø � ø � õ ¼ ø � º � õ ¼ ø � � � õ ¼ � ø ½ � õ ¼ � ø � õ º � � õ ¼ � � � � õ ¼ � � ¼ � õ ¼ � ¹ � � õ ¼ � ¹ » � õ ¼ � ½ ø � õ ¼ � ½ » � õ ¼ � º ø � õ ¼ � º » � õ ¼ � º � � õ ¼ � » º õ º � õ ¼ � » � � õ ¼ � ¼ º � õ ¼ � ¼ � � õ ¼ � � º � õ ¼ � � � � õ ¼ � ½ � õ ¼ � � õ ¼ � � ½ � õ ¼ � � � õ ¼ ¹ ø ½ õ º � � õ ¼ ¹ ø � õ ¼ ¹ � ½ � õ ¼ ¹ � � õ ¼ ¹ ¹ ½ � õ ¼ ¹ ¹ � õ ¼ ¹ ½ ½ � õ ¼ ¹ ½ � � õ ¼ ¹ º º � õ ¼ ¹ º � � õ ¼ ¹ » º õ º ¼ � õ ¼ ¹ » � � õ ¼ ¹ ¼ º � õ ¼ ¹ ¼ � � õ ¼ ¹ � » � õ ¼ ¹ ø � õ ¼ ¹ » � õ ¼ ¹ � ø � õ ¼ ¹ � » � õ ¼ ½ ø � � õ ¼ ½ ø ¼ õ º » � õ ¼ ½ � � � õ ¼ ½ � ¼ � õ ¼ ½ ¹ ¹ � õ ¼ ½ ¹ � � õ ¼ ½ ½ ¹ � õ ¼ ½ ½ � � õ ¼ ½ º ½ � õ ¼ ½ º � õ ¼ ½ » ½ � õ ¼ ½ » � õ º º � õ ¼ ½ ¼ º � õ ¼ ½ ¼ � � õ ¼ ½ � » � õ ¼ ½ ø � õ ¼ ½ ¼ � õ ¼ ½ � � � õ ¼ ½ � � � õ ¼ º ø ¹ � õ ¼ º ø � õ ¼ º � ½ õ º ½ � õ ¼ º � � � õ ¼ º ¹ » � õ ¼ º ½ ø � õ ¼ º ½ ¼ � õ ¼ º º ¹ � õ ¼ º º � � õ ¼ º » ½ � õ ¼ º » � � õ ¼ º ¼ » � õ ¼ º � � õ º ¹ � õ ¼ º � ¼ � õ ¼ º ¹ � õ ¼ º � õ ¼ º � ½ � õ ¼ º � � � õ ¼ » ø » � õ ¼ » � � � õ ¼ » � � � õ ¼ » ¹ ¹ � õ ¼ » ¹ õ º � � õ ¼ » ½ º � õ ¼ » º ø � õ ¼ » º ¼ � õ ¼ » » ¹ � õ ¼ » » � õ ¼ » ¼ º � õ ¼ » � ø � õ ¼ » � ¼ � õ ¼ » ¹ � õ ¼ » õ º ø � õ ¼ » � º � õ ¼ ¼ ø ø � õ ¼ ¼ ø ¼ � õ ¼ ¼ � ½ � õ ¼ ¼ � � � õ ¼ ¼ ¹ » � õ ¼ ¼ ½ � � õ ¼ ¼ ½ � � õ ¼ ¼ º º � õ ¼ ¼ » ø5.4.3.7

> H B R 1 > k R W ] I d V B D [ J V d U D \ d D B R _ Z R W � U H B R D [ U I C W B K F E J U H B B d B W U F E R B U E U H B W V F F B C U \ F E _ B � U EE _ U I D C U H B R D [ U I C W B R 1 > S > H D [ R D [ U I C W B F B \ F B [ B C U [ U H B R D [ U I C W B I Q I Z K F E J U H B B d B W U F E R B U H I U U H B \ E U B C U D I d\ F E _ B [ H I d d _ B \ d I W B R [ E U H I U U H B B I F U H U B [ U B F F B I R [ U H B I W U V I d F B [ D [ U I C W B E K U H B B I F U H B d B W U F E R B S5.4.3.8

> H B \ E U B C U D I d \ F E _ B D [ J E ] B R I R D [ U I C W B R 1 > K F E J U H B B d B W U F E R B I C R U H B F B [ D [ U I C W B ] I d V B D [F B W E F R B R S5.4.3.9

: B F D K D W I U D E C E K U H B J B I [ V F B R F B [ V d U J I Z _ B W I F F D B R E V U V [ D C G U H B K E d d E Q D C G \ F E W B R V F B OI N I R R D U D E C I d [ B U [ E K U B [ U F B [ V d U [ J I Z _ B E _ U I D C B R Q D U H R D K K B F B C U ] I d V B [ E K � R ° � E F B ] B C R D K K B F B C UR D F B W U D E C [ E K � . � K F E J � 4 � ³_ N K F E J U H B F B [ V d U [ E _ U I D C B R I U ] I F D E V [ ] I d V B [ E K � R ° � � I G F I \ H J I Z _ B \ d E U U B R Q H D W H [ H E Q [ H E Q U H BF B [ D [ U I C W B R B W F B I [ B [ I [ Z J \ U E U D W I d d Z I [ U H B R D [ U I C W B W H E [ B C K E F � R ° � D [ D C W F B I [ B R S 8 [ I J \ d B W V F ] BD [ D d d V [ U F I U B R D C K D G V F B b ³

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �40 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

± ² ³ ´ µ ¶ ² ·¸ ² ´ ¹ ´ º ³ » ¼ ²½ ¹ ´ º ³ » ¼ ² · ¾ ¿ À ¶ ² ³ ¼ Á º ² ´ º

� Â Ã Ä � � Â Ã Ä � � Â Ã Ä ¨ � Â Ã Ä ÅFigure 6 – Possible results from several slope method tests W N U H D [ W V F ] B [ H E Q [ U H I U R D [ U I C W B [ W H E [ B C K E F � R W � D C > B [ U a I C R > B [ U T Q B F B D C [ V K K D W D B C U _ B W I V [ B U H B] I d V B D [ K I d d D C G � I C R U H I U U H E [ B W H E [ B C K E F > B [ U X I C R > B [ U ^ Z D B d R B R U H B J E F B W E F F B W U ] I d V B E KB I F U H F B [ D [ U I C W B ³R N D U D [ V C F B I [ E C I _ d B U E B M \ B W U I C I W W V F I W Z E K F B I R D C G [ _ B U U B F U H I C ` � _ B W I V [ B E K ] I F D I U D E C R V B U EU H B [ E D d J E D [ U V F B W E C U B C U I C R D U [ C E C i H E J E G B C B D U Z S 9 B I R D C G I W W V F I W Z E K a f � D [ J E F B F B I d D [ U D W ³I C RB N U H B _ B [ U G V I F I C U B B E K I [ I U D [ K I W U E F Z J B I [ V F B J B C U D [ U E I W H D B ] B [ \ I W D C G _ B U Q B B C U H B U B [ U B RB d B W U F E R B � U H B \ E U B C U D I d \ F E _ B I C R U H B W V F F B C U \ F E _ B � [ V W H U H I U U H B J V U V I d F B [ D [ U I C W B [ I F B[ V K K D W D B C U d Z [ J I d d I C R U H B \ d E U U B R W V F ] B K d I U U B C [ E V U _ B K E F B F D [ D C G I G I D C S

5.5 Earth surface potential measurement > E K D C R I C I \ \ F E M D J I U B ] I d V B E K [ U B \ I C R U E V W H \ E U B C U D I d [ U E Q H D W H I \ B F [ E C J D G H U _ B [ V _ � B W U B R R V F D C GW V F F B C U R D [ W H I F G B U H F E V G H I C B I F U H B d B W U F E R B � U H B B I F U H K I V d U W V F F B C U d B ] B d J V [ U _ B � C E Q C I C R U H B B I F U HF B [ D [ U I C W B I U U H B \ I F U D W V d I F \ E D C U J V [ U _ B J B I [ V F B R S2 U D [ D J \ E F U I C U U E C E U B U H I U [ U B \ I C R U E V W H \ E U B C U D I d [ I F B [ \ B W D K D W U E U H B \ E [ D U D E C I U Q H D W H U H B Z I F B J B I [ V F B R S5.5.1 Procedure to calculate the touch potential, Ut, at a certain position > H B B I F U H U B [ U B F W E C C B W U D E C [ U E J B I [ V F B U H B W E C U I W U F B [ D [ U I C W B � 9 U � _ B U Q B B C H I C R I C R K E E U I F B D d d V [ U F I U B R D CK D G V F B g S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �41 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Æ Ç È É Ê É Æ Ë É Æ È� � � � �� Ì � � � � Í Î �

Ï Ð Ñ Ð � Ò Ó � � � � Ð Í Ñ� Í � � Ñ � Ð � Ì � � Í Ó � � �

� Ò � � � Ñ � � � Í Ó � � � Ô ÕÖ × ÕØ Ù Ú Û Ø Ü Ç È É ÝØ Æ Þ É ß Ù Ú Û Ø Ü Ç È É ÝØ Æ Þ ÉÆ Ç È É Ê à Þ áâ Ç È

Ú � Ú �Ü � Ü �Figure 7 – Connections to determine touch potential contact resistance > H B J B I [ V F B J B C U \ F E W B R V F B D [ I [ K E d d E Q [ O

5.5.1.1 . E C C B W U U B F J D C I d . a U E U H B B I F U H B d B W U F E R B S . E C C B W U U B F J D C I d 1 a U E U H B J B U I d Q E F � E F I C ZW E C R V W U D ] B \ I F U E K U H B B I F U H B R [ U F V W U V F B _ B D C G U B [ U B R S

5.5.1.2 . E C C B W U U B F J D C I d 1 T U E U H B \ E U B C U D I d \ F E _ B Q H D W H D [ R F D ] B C D C U E U H B G F E V C R I _ E V U a J I Q I Z K F E JU H B J B U I d Q E F � _ B D C G U B [ U B R � I R � I W B C U U E U H B \ E D C U E K U B [ U E C U H B J B U I d Q E F � S

5.5.1.3 . E C C B W U U B F J D C I d . T U E U H B W V F F B C U \ F E _ B Q H D W H [ H I d d _ B [ B U V \ X f J I Q I Z S

5.5.1.4 / \ B F I U B U H B D C [ U F V J B C U I C R F B W E F R U H B F B [ D [ U I C W B F B I R D C G S> H B \ F E [ \ B W U D ] B J I M D J V J U E V W H \ E U B C U D I d R V F D C G K I V d U W E C R D U D E C [ D [ G D ] B C I [ U H B \ F E R V W U E K U H B K I V d U W V F F B C U �2 ã � I C R U H B W E C U I W U F B [ D [ U I C W B � 9 ä Oå æ ççåå è ç ¦�� é7ê

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �42 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

5.5.2 Procedure to calculate the step potential, Us, at a certain position > H B B I F U H U B [ U B F W E C C B W U D E C [ U E J B I [ V F B U H B W E C U I W U F B [ D [ U I C W B � 9 ë � _ B U Q B B C U Q E K B B U � a J I \ I F U � I F BD d d V [ U F I U B R D C K D G V F B e S

Æ Ç È É Ê É Æ Ë É Æ È� � � � �� Ì � � � � Í Î �

Ï Ð Ñ Ð � Ò Ó � � � � Ð Í Ñ� Í � � Ñ � Ð � Ì� � Í Ó � � �� Ò � � � Ñ �� � Í Ó � � � Ô Õ

Ö × ÕØ Ù Ú Û Ø Ü Ç È É ÝØ Æ Þ É ß Ù Ú Û Ø Ü Ç È É ÝØ Æ Þ ÉÆ Ç È É Ê à Þ áâ Ç È

Ú � Ú �Ü � Ü �� Í � � Ñ � Ð � Ì� � Í Ó � � �

Figure 8 – Connections to determine step potential contact resistance > H B J B I [ V F B J B C U \ F E W B R V F B D [ I [ K E d d E Q [ O5.5.2.1

. E C C B W U U B F J D C I d [ . a I C R . T I [ R B [ W F D _ B R K E F R B U B F J D C D C G U E V W H \ E U B C U D I d ] I d V B S5.5.2.2

> Q E \ E U B C U D I d \ F E _ B [ I F B R F D ] B C D C U E U H B G F E V C R Q D U H I a J [ B \ I F I U D E C I U U H B \ E D C U Q H B F B U H BJ B I [ V F B J B C U D [ F B c V D F B R S 2 U D [ C E U C B W B [ [ I F Z K E F U H B \ E U B C U D I d \ F E _ B [ U E _ B D C d D C B Q D U H U H B W V F F B C U \ F E _ BI C R B I F U H B d B W U F E R B S > B F J D C I d 1 a E K U H B B I F U H U B [ U B F D [ W E C C B W U B R U E U H B \ F E _ B C B I F B [ U U H B B I F U H B d B W U F E R B S> B F J D C I d 1 T D [ W E C C B W U B R U E U H B E U H B F \ E U B C U D I d \ F E _ B S5.5.2.3

/ \ B F I U B U H B D C [ U F V J B C U I C R F B W E F R U H B F B [ D [ U I C W B F B I R D C G S> H B \ F E [ \ B W U D ] B J I M D J V J [ U B \ \ E U B C U D I d R V F D C G K I V d U W E C R D U D E C [ D [ G D ] B C I [ U H B \ F E R V W U E K U H B K I V d U W V F F B C U �2 ã � I C R U H B W E C U I W U F B [ D [ U I C W B � 9 ë Oå æ ççåå è ç ¦�� é7ê

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �43 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

5.6 Earth continuity testing > H B E _ � B W U D ] B E K U H B B I F U H W E C U D C V D U Z U B [ U D [ U E W H B W � D K U H B W E C U D C V D U Z \ I U H U H F E V G H E V U U H B Q H E d B D C [ U I d d I U D E C D [W E J \ d B U B I C R E K I W W B \ U I _ d Z d E Q L ì a f f J N F B [ D [ U I C W B S > H D [ D [ [ E U H I U D C U H B B ] B C U E K I C B I F U H K I V d U[ V K K D W D B C U W V F F B C U Q D d d K d E Q U E E \ B F I U B U H B I \ \ F E \ F D I U B \ F E U B W U D E C R B ] D W B S> H B B I F U H U B [ U B F W I C _ B V [ B R U E W E C R V W U I C B I F U H W E C U D C V D U Z U B [ U I [ K E d d E Q [ OI N _ F D R G B B I F U H U B [ U B F U B F J D C I d [ . a I C R 1 a I [ Q B d d I [ 1 T I C R . T ³_ N W E C C B W U U B F J D C I d [ . a I C R . T U E U H B E \ \ E [ D U B B C R [ E K U H B F B [ D [ U I C W B V C R B F U B [ U ³W N E \ B F I U B U H B U B [ U B F U E E _ U I D C U H B F B [ D [ U I C W B F B I R D C G L 9 y N ³R N R D [ W E C C B W U U H B U B [ U d B I R [ K F E J U H B J B I [ V F B R E _ � B W U I C R W E C C B W U U H B J U E G B U H B F S / \ B F I U B U H BU B [ U B F U E E _ U I D C I [ B W E C R F B [ D [ U I C W B F B I R D C G � 9 � S 9 � D [ U H B F B [ D [ U I C W B E K U H B U B [ U d B I R [ ³ I C RB N U H B J B I [ V F B R F B [ D [ U I C W B ] I d V B D [ W I d W V d I U B R _ Z R B R V W U D C G U H B U B [ U d B I R F B [ D [ U I C W B 9 � K F E J U H B] I d V B � 9 y O9 ) 9 y 9 �

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �44 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex A - A guide to the identification and evaluation of various soil types L C E F J I U D ] B N2 R B C U D K D W I U D E C E K U H B [ E D d U Z \ B I U \ F E \ E [ B R [ D U B [ K E F B d B W U F E R B D C [ U I d d I U D E C [ W I C \ F E ] D R B I V [ B K V d D C R D W I U E F I [ U EU H B B M \ B W U B R ] I d V B E K [ E D d F B [ D [ U D ] D U Z S 2 U D [ K E F U H D [ F B I [ E C U H I U [ E D d D R B C U D K D W I U D E C D [ I F B c V D F B J B C U D C I [ E D dF B [ D [ U D ] D U Z [ V F ] B Z S> H B U B F J D C E d E G Z V [ B R D C R B [ W F D _ D C G I C R D R B C U D K Z D C G [ E D d U Z \ B [ D [ D C W d V R B R D C U I _ d B [ 8 S a � 8 S T I C R 8 S X _ B d E Q S> I _ d B 8 S ^ D C R D W I U B [ U H B B M \ B W U B R F B [ D [ U D ] D U Z F I C G B [ K E F U H B R D K K B F B C U [ E D d U Z \ B [ STable A.1 –Terminology used in describing soil types �

Term Field testû � � �

� ñ � ô í ê ñ � ñ ë ì � � ë ó ñ � î ñ ì º � ö ö � � � ì � î ð ê ñ � ñ � � é í ô ì � � � � ý � � � î � � � î � ê · ï � � í ê ñ � ñ ë � � �º � ö ö � � � ì � î ð ó ñ � ì ë � ì � � � þ é � ð ó ë é í ê ö � ë ì � ê · � ö � � � � � � é � � é ö î � � ó � ê ó ê ñ � ô ñ ô � ñ ì ì

Term Field identificationû � � �

è ñ � � é í ê � � ó ì � � ë ó ï � � ð � � ý � � � ñ � ô ê � � ó ì ô í � ë � � � ð î � � � � � � ë ó ï � � ð � �¸ � í � � ï ë è í ì � ô ë � � ï � � ð � � � ó � � î � ì � � ó ñ � ìþ � ï ë � � é ì ì ô í é � ð ó ë ï � � ð � î � � � � ï � � ö � ñ � ô ö � é ì ì ô í � ë � � � ð ï � � ð � î � � � � þ ë � ï ï � ñ � � � ë ô ö � é ì ì ô í ï � � ð � �� ñ � ô � � ì � ë ì ô í ë ó ö ô �¸ � í � ë � ï ï ê ñ � ô � � ì � ë ì ô í ë ó ö ô � ñ � éþ î � � ð í ¸ � í ê � ö î � � � � ô é ñ � ì � î � � ë � ê ë � é ñ � ë � ê � ñ � ô ö � é ì ì � � ó ñ � ì ñ � ì � ö ñ � � � � ï � � ð � �ð � ö � ð � � � ý î � � � ë ê � � � � � ë � � � � ë � ñ é é í � ï � � ë í î ñ � ë � � � ë � ñ ë � ï � ì µ é ë � � ñ ë � � ð é ñ í � � � ï � ñ � í � � ð ë í î � � � � � ë ó ô ñ � ì � � � é � � � � � � ë ó �ö ñ ë � � ñ é �ð ë � � ð � � � µ ö � í ë � � ï ë í î �ò ñ ë ó � ì ñ � ë � ê é � ö ñ í ô � ñ · � ì ñ � ì ö ñ í � ó � � ê � � ê � ë � � ê é ñ í � � � ðï � � � � ì � � ñ · � � � ë � î � é í ó ì � ñ é ï � ñ ð ö � ë � ñ é � � ð ï � � � � �ñ � ë ñ ê ë ü � ï � � � � �ï � ô � � � é ñ � ë � ö ñ � � � � ê � ð � � � ñ ô é ñ � ì � ë ñ � � � � � ö � ë � � ð ë óµ ö � � î ó � � � ê � ð � � � ñ ô é î é ñ � ë � ö ñ � � � ñ ô � � ë

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �45 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex A L . E C U D C V B R NTable A.2 – Colours used in the description of soils �

Colour Shading � ì � � ·ó é é � �� � � � �ù é � � ÿ � �� é ò ó � ë ÿ � í� é ñ ê ·û � ð ó ëý ñ � ·� � ë ë é ì

Table A.3 – Identification of soils � ¼ »Soil types Particle size Visual identification Nature and colourû � ñ ö �

¸ ñ � � �

� ì � ö � � ñ � ë é í î é ñ � ë � ö ñ � � � �

ï � � ö ë � î é ñ � ë � ê ô � � � � ë � ô é ñ ê · � � é ë õê é ñ í ñ � ì î ñ ë � ï ë � � � ë ó ñì � � ë � � ê ë � � � ö é é � � ë ó ñ é � � ô é ·ì � � � ë í �ÿ ñ � ì � � � � é � ¸ ñ � � � þ ô � ë ñ � ë � ñ é � � ð ñ � � ê ö ñ ë ë � � � ë ó ê é ñ í õ� � é ë � � � ñ � ì � � ì � ö ì � � ë � ï � � ö é � ð ó ë ô � � � �ë � ì ñ � · ô � � � � ê é ñ í í � ñ � ì � �� é ñ í � þ � � é � � ë ó ñ �� õ � � � ö ö þ ö � � ë ó ë � ë ó ë � ê ó � þ ë � ê · � ë � ë ó ï � � ð � � � þ ó � � � · � ñ î î � ê � ñ ô é í � �ì � í � � ð � ñ � ë � ö ì � ñ ë ë � ó � ð ó î é ñ � ë � ê � ë í � �ñ � í ê � é � � � ý � � � � é � � é í �þ � é ë � ï � � ë � ê � ñ � � � õ � � � ö ö ë �� õ ö ö ù � é í ê � ñ � � � � é ë ô ñ � é í � � � � ô é �þ é � ð ó ë é í ð � ñ � é ñ � � � � � é · í ë � ë � ê ó � û � ð ó ë ô � � � � � � é ë í � è ñ � � é í î � � ì � ìô ë � � ï � � ð � � � ý � � � � ë ð � ñ ë � � �� ñ ë � � ü � � � î é ñ � ë � ê �þ ñ � ì � ï � � ë � ê � ñ � � � õ ö ö ë � � ö ö ¸ � � � ô é ë � � ñ · ì í � û � ë ë é � � � �ê � ó � � � � � ó � ì � í � ÿ � ñ ì � � ð ê ñ � ô ì � ê � � ô ì � þ ö � � ë ó ë � � � ð ó é � ð ó ë ô � � � � ë �í é é � � õ é � � � ë � � é � ð ó ë é í ê ö � ë ñ éî ñ � ë � ê é � �ÿ � ñ � é � � ö ö ë � ½ ö ö è ñ � � é í � � � � ô é ë � ë ó � ñ · ì í � ñ � ë � ê é � ó ñ î ê ñ � ô ì � ê � � ô ì �ÿ � ñ ì � � ð ê ñ � ô ì � ê � � ô ì � µ � ð é ñ � õ � � � ì ì õ ï é ñ ë � � é � � ð ñ ë � ó ñ î � � � � ñ � � � � ê � é � � � �� � ô ô é �� � é ì � � ½ � ö ö ë � � � � ö ö� � � ô ö ö ý � ï ï � ê é ë ë � � ê � � � ï � � ö ô � � ó � é � õ� � ö ë � ö � � � é í � � � � � î � í ê ñ � ñ ë � � � � ý � ï ï � � ë � ó ñ î � õ � � � � ñ � ìê � é � � � �� � ê · �ï � é � ñ ë ìü � � � ï � é � ñ ë ì � é ñ � � � � ë � î é ñ ë � �ð ñ � ì õ ö ñ � � � � õ ï � � ë � ê � ñ � � ð � ñ ì ì �

Table A.4 – Typical soil resistivity values �Type of soil Typical resistivity in

ö û � ñ ö � õ ð ñ � ì � � � � é � ë ê � �� é ñ í �� é ñ í õ � ñ � ì õ ð � ñ � é ö � í ë � �þ ñ � ì õ ð � ñ � éþ é ñ ë � õ � ó ñ é õ � ñ � ì � ë � � � � í � ë ñ é é � � � � ê · �

º�» �½ � �� � �ë �ë �ë �ë �ë �ë �

º �º �� º � � �º � � � � � �

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �46 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex B – Electrode enhancement L C E F J I U D ] B NB.1 Conductive concrete > H B \ F I W U D W B E K B C W I [ D C G B I F U H B d B W U F E R B [ D C W E C R V W U D ] B W E C W F B U B L [ B B 5 i 5 > i X T f ` N D [ I C B M \ B C [ D ] B J B I C [E K F B R V W D C G U H B B d B W U F E R B F B [ D [ U I C W B U E U F V B B I F U H S 2 C [ E J B W D F W V J [ U I C W B [ � H E Q B ] B F � D U D [ U H B E C d Z \ F I W U D W I dQ I Z E K F B R V W D C G U H B B d B W U F E R B F B [ D [ U I C W B U E Q D U H D C I C I W W B \ U I _ d B d D J D U S> H B V [ B E K W E C R V W U D ] B W E C W F B U B W I C F B [ V d U D C d E Q B d B W U F E R B F B [ D [ U I C W B ] I d V B [ U H I U I F B d B [ [ [ V [ W B \ U D _ d B U EK d V W U V I U D E C Q D U H I J _ D B C U U B J \ B F I U V F B � H V J D R D U Z I C R F I D C K I d d U H I C I F B C E C i B C W I [ B R B d B W U F E R B [ I C R U H E [ BQ H B F B U H B [ E D d H I [ _ B B C W H B J D W I d d Z U F B I U B R S 4 C W I [ B R B d B W U F E R B [ I F B I d [ E d B [ [ [ V [ W B \ U D _ d B U E U H B K U S> H B I \ \ d D W I U D E C E K W E C R V W U D ] B W E C W F B U B D [ W E C [ U F I D C B R _ Z H D G H W E [ U I C R [ H E V d R E C d Z _ B W E C [ D R B F B R D C U H BK E d d E Q D C G [ D U V I U D E C [ OI N Q H B F B [ \ I W B d D J D U I U D E C [ D C H D _ D U U H B I \ \ d D W I U D E C E K B d B W U F E R B [ Q D U H d I F G B R D J B C [ D E C [ ³_ N I [ I C I d U B F C I U D ] B U E R B B \ R F D d d B R H E d B [ S > H B R B \ U H E K R F D d d B R H E d B [ W I C _ B F B R V W B R _ Z V \ U E X f � I Ud D U U d B E F C E B M U F I W E [ U ³W N K E F B d B W U F E R B [ D C ? � 4 9 [ Z [ U B J [ Q H B F B ] B F Z d E Q F B [ D [ U I C W B [ I F B F B c V D F B R ³ I C RR N Q H B F B W E \ \ B F U H B K U D [ \ F B ] I d B C U S> H B I \ \ d D W I U D E C E K W E C R V W U D ] B W E C W F B U B D [ J E [ U B K K B W U D ] B Q H B F B U H B F B [ D [ U D ] D U Z E K U H B [ E D d � B � D [ G F B I U B F U H I Ca f f U D J B [ U H I U E K U H B W E C W F B U B � W L D S B S B ö a f f W N S . E C R V W U D ] B W E C W F B U B D [ d B [ [ B K K B W U D ] B D C J E F BW E C R V W U D ] B [ E D d [ I C R [ H E V d R C E U _ B V [ B R D C W I [ B [ Q H B F B U H B [ E D d F B [ D [ U D ] D U Z D [ d B [ [ U H I C X f f J SB.1.1 Standard electrode configurations employing conductive concrete > H B \ F D C W D \ I d I \ \ d D W I U D E C E K W E C R V W U D ] B W E C W F B U B D C B I F U H D C G D [ U E [ D U V I U D E C [ Q H B F B [ \ I W B D [ d D J D U B R S 2 U D [ K E FU H D [ F B I [ E C U H I U U H B [ U I C R I F R W E C R V W U D ] B W E C W F B U B B C W I [ B R B d B W U F E R B D [ I [ D C G d B R B B \ i R F D d d B R ] B F U D W I dW E C R V W U E F B d B W U F E R B S> H F B B [ U I C R I F R B I F U H B d B W U F E R B [ B J \ d E Z D C G W E C R V W U D ] B W E C W F B U B I F B [ \ B W D K D B R D C > I _ d B 6 S a S

Table B.1 – Standard 30 earth electrode configurations using conductive concrete

Description Alternative main earth electrode è é ê ë � � ì ë í î � ¼è é ê ë � � ì ê � � ï � ð � ñ ë � � � ý � � é é ì ÷ ó � é � � ë � ê ñ é ê � � ì ê ë � � � ê ñ � ì � � ê � � ì ê ë � � ê � � ê � ë µ î î é � ê ñ ô é � � � é � � � � ë � � � ë í ñ ë ñì î ë ó � ï � õ º ö ë � õ º ö´ � � ö ¶ ÷ ½ � � ÷ ø � � ÷ º � �è é ê ë � � ì ì � ö � � � � � � ´ ö ¶ú ò � � ê ó ì î ë ó ´ ö � � � ö ö ¶ � õ º � õ º � õ ºú ¸ � ë � ê ñ é ê � � ì ê ë � � é � ð ë ó � � õ � ¼ º õ � ½ � õ �ú ý � ñ ö ë � � ï ê � � ì ê ë � � ê � � ê � ë � ê ñ � ö � ë � õ � õ � õ ü ö ô � � ï � � ì � NOTE:

} r p q � � y � � o � r p � w o y o � n u t t p r y � o o x � t r � o q s n o w o y n o � r � t w o � � � y � � � y � � �   ­ ­ x r w t o � � �� H B F B U H B [ U I C R I F R B d B W U F E R B U Z \ B [ W I C C E U _ B D C [ U I d d B R � U H B I d U B F C I U D ] B [ D C U I _ d B 6 S a I [ H I d d _ B W E C [ D R B F B R S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �47 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex B L . E C U D C V B R NTable B.1a – Alternative 30 earth electrode configurations using conductive concrete

Description Alternative main earth electrode è é ê ë � � ì ë í î � ¼è é ê ë � � ì ê � � ï � ð � ñ ë � � � � � ð ó ë ñ � ð é ë � � � � � � � é � � � � ë ó ê � � ì ê ë � � ê � � ê � ë � ê ñ � ì� � ë � ê ñ é ê � � ì ê ë � � �µ î î é � ê ñ ô é � � � é � � � � ë � � � ë í ñ ë ñì î ë ó � ï � õ º ö ë � õ º ö´ � � ö ¶ ÷ ½ � � ÷ ø � � ÷ º � �è é ê ë � � ì ì � ö � � � � � � ´ ö ¶ú ò � � ê ó ì î ë ó ´ ö � � � ö ö ¶ � õ º � õ º � õ ºú � ñ ì � ñ é é � ð ë ó ´ û ¶ � õ � � õ � � � õ �ú ¸ � ë � ê ñ é ê � � ì ê ë � � é � ð ë ó ¹ õ � õ � � � õ �ú ¸ � ë � ê ñ é ê � � ì ê ë � �� î ñ � ñ ë � � � ì � � ë ñ � ê � õ � � õ � � � õ �ú ý � ñ ö ë � � ï ê � � ì ê ë � � ê � � ê � ë � ê ñ � � � ð � � ë � ê ñ éê � � ì ê ë � � � � õ � õ � õ ú ý � ñ ö ë � � ï ê � � ì ê ë � � ê � � ê � ë � ê ñ � � � ð ó � � � � � � ë ñ éê � � ì ê ë � � � � � �ü ö ô � � ï � � ì � ¼ ¼ ¼ý � ñ ð � ñ ö ö ñ ë � ê � î � � � ë ñ ë � � �NOTE:

} r p q � � y � � o � r p � w o y o � n u t t p r y � o o x � t r � o q s n o w o y n o � r � t w o � � � y � � � y � � �   ­ ­ x r w t o � � �ûûûû ûû û ûû ûû û

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �48 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex B L . E C U D C V B R NB.1.2 Electrode selection > H B [ B d B W U D E C E K I C I \ \ F E \ F D I U B [ U I C R I F R B d B W U F E R B K E d d E Q [ U H B \ F E W B R V F B E V U d D C B R D C [ B W U D E C ^ S b S X SB.1.3 Application of conductive concrete . E C R V W U D ] B W E C W F B U B K E F V [ B D C B I F U H D C G I \ \ d D W I U D E C [ [ H I d d W E C K E F J U E 5 i 5 > i X T f ` S. E C R V W U D ] B W E C W F B U B [ H I d d _ B I \ \ d D B R U E U F B C W H B d B W U F E R B [ I C R ] B F U D W I d R F D d d B R i H E d B B d B W U F E R B [ I [ K E d d E Q [ OI N 8 \ \ d D W I U D E C E K W E C R V W U D ] B W E C W F B U B U E I U F B C W H B d B W U F E R B OI d I Z B F E K W E C R V W U D ] B W E C W F B U B [ H I d d _ B \ d I W B R I U U H B _ E U U E J E K U H B U F B C W H �I W E C U D C V E V [ d B C G U H E K W E \ \ B F [ H I d d _ B \ d I W B R E C U E \ E K U H B Q B U W E C R V W U D ] B W E C W F B U B �I [ B W E C R d I Z B F E K W E C W F B U B [ H I d d _ B \ E V F B R E C U E \ E K U H B \ F B ] D E V [ d I Z B F I C R U H B W E \ \ B FW E C R V W U E F � I C RU H B U F B C W H J I Z _ B _ I W � i K D d d B R E C W B U H B W E C W F B U B H I [ [ B U U d B R I C R H I F R B C B R S > H D [ [ H I d d _ B\ E [ [ D _ d B I K U B F X R I Z [ Q H B C U H B [ U F B C G U H E K U H B W E C W F B U B H I [ F B I W H B R I \ \ F E M D J I U B d Z ^ ` � E KU H B R B [ D G C [ U F B C G U H SNOTE: � n o s � q y n r v y n o � r p � w o y o � t u � s � t t � o q o y o w x � p o q � � y n o s � q y n r v y n o y w o p � n � � n o y r y u t n o � � n y r v y n o � t u � � n u t t p r yo ¾ � o o q � ­ ­ x x �_ N 8 \ \ d D W I U D E C E K W E C R V W U D ] B W E C W F B U B U E I ] B F U D W I d W E C R V W U E F B d B W U F E R B OI W E C U D C V E V [ d B C G U H E K W E \ \ B F [ H I d d _ B D C [ B F U B R K E F U H B K V d d d B C G U H E K U H B _ E F B R H E d B � I C RU H B W E C R V W U D ] B W E C W F B U B [ H I d d U H B C _ B W I [ U I F E V C R U H B W E \ \ B F F E R �NOTE: � y u p q u w q � r w o ¡ n r t o q � u x o y o w � u w o u q o � � u y o v r w y n o � p � y u t t u y � r p r v � o w y � � u t � r p q � � y � � o � r p � w o y o o t o � y w r q o � � { q � u x o y o wr v ¢ ­ ­ x x r w ¢ « ­ x x � � w o � r x x o p q o q �

B.2 Chemical treatment of the soil surrounding an earth electrode > H B J B U H E R E K W H B J D W I d d Z U F B I U D C G U H B [ E D d I F E V C R I C B I F U H B d B W U F E R B D [ E K U B C E C d Z I U B J \ E F I F Z [ E d V U D E C U EU H B \ F E _ d B J E K H D G H B d B W U F E R B F B [ D [ U I C W B S > H B F B D [ I U B C R B C W Z K E F U H B I \ \ d D B R [ I d U [ U E _ B Q I [ H B R I Q I Z _ Z[ B I [ E C I d F I D C S > H D [ J I � B [ D U C B W B [ [ I F Z K E F E \ B F I U D C G I C R J I D C U B C I C W B [ U I K K U E F B I \ \ d Z U H B U F B I U J B C U B ] B F ZK B Q Z B I F [ S . H B J D W I d U F B I U J B C U E K U H B [ E D d [ V F F E V C R D C G I C B d B W U F E R B [ H I d d E C d Z _ B W E C [ D R B F B R D C B M W B \ U D E C I dW D F W V J [ U I C W B [ Q H B F B C E E U H B F \ F I W U D W I d [ E d V U D E C B M D [ U [ S. H B J D W I d [ W E J J E C d Z V [ B R K E F U F B I U D C G U H B [ E D d I F B OI N J I G C B [ D V J [ V d K I U B ³ E F_ N W I d W D V J [ V d K I U B S/ U H B F W H B J D W I d [ J I Z _ B V [ B R _ V U W I F B [ H I d d _ B B M B F W D [ B R _ B W I V [ B E K U H B D F \ E [ [ D _ d B W E F F E [ D ] B B K K B W U [ E C U H BB I F U H B d B W U F E R B S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �49 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex B L . E C U D C V B R NB.2.1 Magnesium sulfate 0 I G C B [ D V J [ V d K I U B D [ \ E [ [ D _ d Z U H B d B I [ U W E F F E [ D ] B E K U H B W H B J D W I d [ V [ B R D C [ E D d U F B I U J B C U S 6 Z Q B D G H U � T T � GU E ^ ` � G J I Z _ B C B B R B R I [ I C D C D U D I d U F B I U J B C U S > H B W H B J D W I d [ H I d d _ B B ] B C d Z [ W I U U B F B R E C U H B [ V F K I W B E KU H B G F E V C R _ V U C E U D C R D F B W U W E C U I W U Q D U H U H B B d B W U F E R B F E R E F F E R [ S8 d U B F C I U D ] B d Z I U F B C W H J I Z _ B R V G I F E V C R B I W H F E R E K U H B [ Z [ U B J S > H B U F B C W H [ H I d d H I ] B I R D I J B U B F E KI \ \ F E M D J I U B d Z f � ` J I C R I R B \ U H E K f � X J S > H B W H B J D W I d D [ \ d I W B R D C U H B U F B C W H I C R W E ] B F B R Q D U H [ E D d S= E F J I d F I D C K I d d Q D d d R D [ \ B F [ B U H B W H B J D W I d I R B c V I U B d Z D C U H B [ E D d � _ V U D C R F Z Q B I U H B F W E C R D U D E C [ E F Q H B F B d D U U d BF I D C D [ B M \ B W U B R U H B W H B J D W I d U F B I U J B C U [ H I d d _ B Q I U B F B R D C S 8 K B Q H E V F [ E K H B I ] Z Q I U B F [ \ F D C � d D C G [ H E V d R_ B [ V K K D W D B C U S; V F U H B F U F B I U J B C U J I Z _ B C B B R B R B ] B F Z U H F B B U E K D ] B Z B I F [ U E J I D C U I D C U H B F B c V D F B R B I F U H F B [ D [ U I C W B � _ V U IW d E [ B W H B W � [ H I d d _ B � B \ U E C U H D [ ] I d V B S 2 C ] B F Z Q B U W d D J I U B [ J E F B K F B c V B C U U F B I U J B C U J I Z _ B C B W B [ [ I F Z_ B W I V [ B U H B W H B J D W I d J I Z \ E [ [ D _ d Z _ B Q I [ H B R E V U E K U H B [ E D d S . H B J D W I d U F B I U J B C U R E B [ H I ] B U H BI R ] I C U I G B E K F B R V W D C G U H B ] I F D I U D E C D C B I F U H B d B W U F E R B F B [ D [ U I C W B W I V [ B R _ Z [ B I [ E C I d W d D J I U D W W H I C G B [ � D S B SQ B U \ B F D E R [ K E d d E Q B R _ Z R F Z E C B [ SB.2.2 Calcium sulfate . I d W D V J [ V d K I U B L G Z \ [ V J N D [ Q D R B d Z V [ B R U E W H B J D W I d d Z U F B I U [ E D d S 2 U D [ d B [ [ [ E d V _ d B D C Q I U B F U H I C E U H B FW H B J D W I d [ O T � ^ G k d D U F B S > H B F B [ D [ U D ] D U Z E K U H B [ I U V F I U B R [ E d V U D E C D [ _ B U Q B B C ` J I C R a f J S. E J \ I F B R U E W E J J E C [ I d U � W I d W D V J [ V d K I U B W I C \ F E ] D R B I C e f � D J \ F E ] B J B C U D C F B [ D [ U D ] D U Z I C R D U I d [ E R E B [C E U Q I [ H E V U E K U H B [ E D d B I [ D d Z S > H B W H B J D W I d W I C _ B R D [ [ E d ] B R D C Q I U B F Q H D W H D [ U H B C [ \ F D C � d B R E ] B F U H BI F B I W E C W B F C B R S ` f � G E K G Z \ [ V J Q D d d \ F E ] D R B T f � f f f d D U F B [ E K [ E d V U D E C Q D U H I W E C [ U I C U F B [ D [ U D ] D U Z E K g � ` fJ SNOTE: � r t � � t o � � t v u y o � u y y u � § y n o � o x o p y � p � r p � w o y o � u � � � p � o ¾ � u p � � r p u p q � w u � § � p � � � n o w o v r w o � � � � n � r � t y w o u y x o p y x � � yp r y � o u � � t � o q s n o w o y n o w o � � u p � q u p � o w u v v o � y � p � y n o � r p � w o y o v r � p q u y � r p � r v � � � t q � p � � o y � � m n o w o � y � � v o t y y n u y � r t � � t o� � t v u y o � u w o y r � o � � o q � y � � s � � o y r o p � � w o y n u y y n o o u w y n o t o � y w r q o � � � y o x � � � � y o q u y u � u v o q � � y u p � o u s u � v w r x � � � t q � p � � �> H B I \ \ d D W I U D E C W F D U B F D I K E F U H B W H B J D W I d U F B I U J B C U E K [ E D d I F B \ F B [ B C U B R D C > I _ d B 6 S T _ B d E Q S

Table B.2 – Chemical treatment application criteria �Description of soil

Structure and climate

Chemical treatment ý � í ÷ � � ê · í ÷ � ñ � ì í � � � é õ ó � ë ê é � ö ñ ë � ñ ð � � � ö � é ï ñ ë � º · ðû � ë ë é � ñ � � ï ñ é é � ñ � � ë ñ � � ö � � � ë ê � � � � ó � î � � � � ô é ý � é � ö � ë ñ � ì ê � í � ë ñ é é � � � � ê · � õ î � � ô ñ ô � é � ë í � ï � ì � é í � � ð � ñ ë � ë ñ ô é � ñ é ê � ö � é ï ñ ë � õ » ð � é ñ î î é í º � éB.3 References ø a ù . H I \ J I C � 5 I F F Z d L a h h e N S 5 B ] B d E \ J B C U E K I W E J \ I W U B I F U H B d B W U F E R B S 4 [ � E J > 9 2 F B [ B I F W H F B \ E F U O> 9 9 k 4 k 4 3 f a ^ S ø 8 [ U V R Z E C U H B I \ \ d D W I U D E C E K W E C R V W U D ] B W E C W F B U B ù S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �50 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex C - Clarification of the MV/LV earthing philosophy at equipment installations L = E F J I U D ] B N

C.1 Transformer installations

C.1.1 The requirement of an LV earth [3] > H B F B I [ E C [ K E F B I F U H D C G U H B C B V U F I d E K I C 3 : [ Z [ U B J I F B OI N U E \ F E ] D R B I W E C R V W U D ] B F B U V F C \ I U H E K I C Z B I F U H K I V d U I C R B I F U H d B I � I G B W V F F B C U ³_ N U E J I D C U I D C U H B C B V U F I d E K U H B 3 : [ Z [ U B J I [ W d E [ B I [ \ E [ [ D _ d B U E B I F U H \ E U B C U D I d ³W N U E B C [ V F B U H I U U H B 0 : \ F E U B W U D E C E \ B F I U B [ D C U H B B ] B C U E K I K I V d U _ B U Q B B C U H B 0 : I C R 3 : Q D C R D C G [E K I U F I C [ K E F J B F ³ I C RR N U E F B R V W B U H B \ F E [ \ B W U D ] B U E V W H ] E d U I G B I [ J V W H I [ D [ F B I [ E C I _ d Z \ F I W U D W I d S8 U U B C U D E C D [ R F I Q C U E U H B K I W U U H I U E C > = i ? I C R > = i . i ? 3 : B I F U H D C G [ Z [ U B J [ � U H B _ E C R B R J B U I d Q E F � D CW V [ U E J B F � [ D C [ U I d d I U D E C [ D [ W E C C B W U B R U E U H B 3 : C B V U F I d \ E D C U E K U H B [ V \ \ d Z U F I C [ K E F J B F _ Z U H B 1 4 E F 1 4 =W E C R V W U E F S 9 I D [ D C G U H B \ E U B C U D I d E K U H B 3 : C B V U F I d Q D d d F I D [ B U H B \ E U B C U D I d E K U H B W V [ U E J B F � [ _ E C R B RJ B U I d Q E F � SC.1.2 The requirement of an MV earth > H B 0 : B I F U H B d B W U F E R B D [ [ V \ \ d D B R D C E F R B F U E \ F E ] D R B 0 : [ V F G B I F F B [ U B F [ Q D U H I R D [ W H I F G B \ I U H K E F [ V F G BW V F F B C U [ S2 U D [ W V F F B C U \ F I W U D W B K E F U H B U F I C [ K E F J B F U I C � I C R W E F B U E _ B _ E C R B R U E U H B 0 : B I F U H B d B W U F E R B S 8 d U H E V G H U H B] E d U I G B R B ] B d E \ B R I W F E [ [ I [ V F G B I F F B [ U B F R V F D C G [ V F G B W V F F B C U R D [ W H I F G B D [ d D J D U B R _ Z R B [ D G C � U H B ] E d U I G BR B ] B d E \ B R I W F E [ [ U H B B I F U H D C G d B I R D C R V W U I C W B I C R B I F U H B d B W U F E R B D J \ B R I C W B J I Z _ B ] B F Z d I F G B S > H BW E J _ D C B R ] E d U I G B I W F E [ [ U H B I F F B [ U B F I C R B I F U H D C G [ Z [ U B J J I Z _ B [ V K K D W D B C U U E W I V [ B _ F B I � R E Q C E K U H BD C [ V d I U D E C _ B U Q B B C U H B 0 : \ H I [ B [ I C R U F I C [ K E F J B F U I C � E F W E F B S 6 Z W E C C B W U D C G U H B [ V F G B I F F B [ U B F U I D d [R D F B W U d Z U E U H B U I C � � I C R W E C C B W U D C G U H B U I C � U E B I F U H � U H B ] E d U I G B [ U F B [ [ I W F E [ [ U H B D C [ V d I U D E C D [ d D J D U B R U EU H B I F F B [ U B F R D [ W H I F G B ] E d U I G B S 5 V F D C G [ V F G B R D [ W H I F G B [ � U H B \ E U B C U D I d E K U H B U F I C [ K E F J B F U I C � D [ F I D [ B R U EU H B ] E d U I G B R F E \ I W F E [ [ U H B B I F U H D C G [ Z [ U B J SC.1.3 The use of a combined LV/MV earth at transformer installations [1] > H B W E J _ D C I U D E C E K 0 : I C R 3 : B I F U H [ D C U E I [ D C G d B B d B W U F E R B Q I [ U H B \ F B K B F F B R B I F U H D C G [ W H B J B D C 4 [ � E JV C U D d U H B B I F d Z a h e f [ S 8 U U H D [ U D J B � I C B Q . E R B E K 1 F I W U D W B Q I [ \ V _ d D [ H B R Q H D W H B M \ E [ B R I H I � I F R E K [ H E W �U H I U Q E V d R _ B \ F B [ B C U B R U E W V [ U E J B F [ D C U H B B ] B C U E K \ E Q B F K F B c V B C W Z W V F F B C U K d E Q U H F E V G H U H B W E J _ D C B RB I F U H B d B W U F E R B S > E R I Z � I W E J _ D C B R B d B W U F E R B [ H I d d E C d Z _ B D C [ U I d d B R Q H B F B U H B B d B W U F E R B F B [ D [ U I C W B U E U F V BB I F U H D [ C E J E F B U H I C a S> H B E C d Z B M W B \ U D E C U E U H D [ F V d B D [ K E F F B J E U B U F I C [ K E F J B F [ U H I U [ V \ \ d Z I [ D C G d B V C J I C C B R D C [ U I d d I U D E C S 2 K R V BU E \ E E F [ E D d D U Q E V d R W E [ U U E E J V W H U E J B B U U H B X f 0 : B I F U H B d B W U F E R B D J \ B R I C W B W F D U B F D E C U H B C U H B 0 :I C R 3 : B I F U H B d B W U F E R B [ J I Z _ B W E J _ D C B R D C U E I [ D C G d B B d B W U F E R B S> H D [ [ D C G d B B I F U H B d B W U F E R B [ H I d d H I ] B I d E Q B C E V G H D J \ B R I C W B U E B C [ V F B U H I U U H B [ B C [ D U D ] B B I F U H K I V d U\ F E U B W U D E C Q D d d E \ B F I U B D C U H B B ] B C U E K I K I V d U S> H B F B I [ E C U H I U D U D [ \ B F J D [ [ D _ d B U E W E J _ D C B U H B 0 : I C R 3 : B I F U H B d B W U F E R B [ K E F F B J E U B U F I C [ K E F J B F [ D [ U H I UU H B F D [ � E K [ E J B E C B _ B D C G D C U H B ] D W D C D U Z E K U H B U F I C [ K E F J B F L E F U E V W H D C G J B U I d Q E F � _ E C R B R U E U H B 3 : C B V U F I dW E C R V W U E F R V F D C G U H B K I V d U N D [ B M U F B J B d Z d E Q S> H B F D [ � \ F E K D d B [ E K U H B ] I F D E V [ W I U B G E F D B [ D [ F B W E F R B R _ B d E Q S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �51 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex C L . E C U D C V B R NElectrification 0 I C Z W V [ U E J B F [ I F B K B R K F E J I [ D C G d B U F I C [ K E F J B F S > H B \ F E _ I _ D d D U Z E K [ E J B E C B W E J D C G D C U E W E C U I W UQ D U H _ E C R B R J B U I d Q E F � R V F D C G I K I V d U D [ H D G H S= E B c V D \ E U B C U D I d _ E C R D C G D C J I C Z E K U H B D C [ U I d d I U D E C [ R V B U E U H B D C K E F J I d W E C [ U F V W U D E C U B W H C D c V B [ Q B F BU E F D [ B D C \ E U B C U D I d R V B U E I C 0 : K I V d U U E U H B U F I C [ K E F J B F U I C � S> H B F B I F B E K U B C C E \ F E \ B F K d E E F [ S > H D [ F B R V W B [ U H B D J \ B R I C W B E K U H B K I V d U W V F F B C U \ I U H U H F E V G H I\ B F [ E C � [ _ E R Z U E B I F U H S> H B \ B F [ E C U E V W H D C G U H B _ E C R B R J B U I d Q E F � J I Z H I ] B _ I F B K B B U L W H D d R F B C N S/ ] B F I d d F D [ � O @ D G H SUrban 0 I C Z W V [ U E J B F [ I F B K B R K F E J I [ D C G d B U F I C [ K E F J B F S > H B \ F E _ I _ D d D U Z E K [ E J B E C B W E J D C G D C U E W E C U I W UQ D U H _ E C R B R J B U I d Q E F � R V F D C G I K I V d U D [ H D G H S1 F E \ B F B c V D \ E U B C U D I d _ E C R D C G L D C I W W E F R I C W B Q D U H ? 8 6 ? f a ^ T N D [ W I F F D B R E V U D C B I W H D C [ U I d d I U D E C S > H D [F B R V W B [ U H B U E V W H ] E d U I G B [ U H I U Q E V d R _ B \ F B [ B C U D C U H B D C [ U I d d I U D E C D K U H B 3 : C B V U F I d W E C R V W U E F Q B F BU E F D [ B D C \ E U B C U D I d R V B U E I C 0 : K I V d U U E U H B U F I C [ K E F J B F U I C � S> H B F B Q E V d R _ B \ F E \ B F K d E E F [ D C U H B D C [ U I d d I U D E C S > H D [ D C W F B I [ B [ U H B D J \ B R I C W B E K U H B K I V d U W V F F B C U \ I U HU H F E V G H I \ B F [ E C � [ _ E R Z U E B I F U H S/ ] B F I d d F D [ � O 0 B R D V J SFarms ; B Q W V [ U E J B F [ I F B K B R K F E J B I W H U F I C [ K E F J B F S > H B \ F E _ I _ D d D U Z E K [ E J B E C B W E J D C G D C U E W E C U I W U Q D U H_ E C R B R J B U I d Q E F � R V F D C G I K I V d U D [ d E Q S1 F E \ B F B c V D \ E U B C U D I d _ E C R D C G L D C I W W E F R I C W B Q D U H ? 8 6 ? f a ^ T N D [ W I F F D B R E V U D C B I W H D C [ U I d d I U D E C S > H D [F B R V W B [ U H B U E V W H ] E d U I G B [ U H I U Q E V d R _ B \ F B [ B C U D C U H B D C [ U I d d I U D E C D K U H B 3 : C B V U F I d W E C R V W U E F Q B F BU E F D [ B D C \ E U B C U D I d R V B U E I C 0 : K I V d U U E U H B U F I C [ K E F J B F U I C � S> H B F B Q E V d R _ B \ F E \ B F K d E E F [ D C U H B D C [ U I d d I U D E C S > H D [ D C W F B I [ B [ U H B D J \ B R I C W B E K U H B K I V d U W V F F B C U \ I U HU H F E V G H I \ B F [ E C � [ _ E R Z U E B I F U H S/ ] B F I d d F D [ � O 3 E Q SRemote > H B D C [ U I d d I U D E C D [ V C J I C C B R I C R U H B F B D [ [ B d R E J I C Z E C B D C U H B I F B I S > H B \ F E _ I _ D d D U Z E K [ E J B E C BW E J D C G D C U E W E C U I W U Q D U H _ E C R B R J B U I d Q E F � R V F D C G I K I V d U D [ ] B F Z d E Q S1 F E \ B F B c V D \ E U B C U D I d _ E C R D C G L D C I W W E F R I C W B Q D U H ? 8 6 ? f a ^ T N D [ W I F F D B R E V U D C B I W H D C [ U I d d I U D E C S > H D [F B R V W B [ U H B U E V W H ] E d U I G B [ U H I U Q E V d R _ B \ F B [ B C U D C U H B D C [ U I d d I U D E C D K U H B 3 : C B V U F I d W E C R V W U E F Q B F BU E F D [ B D C \ E U B C U D I d R V B U E I C 0 : K I V d U U E U H B U F I C [ K E F J B F U I C � S2 C I F B J E U B [ D U B I C Z E C B Q H E J I Z _ B I F E V C R U H B D C [ U I d d I U D E C Q D d d _ B Q B I F D C G [ H E B [ S/ ] B F I d d F D [ � O : B F Z d E Q S/ C d Z U H B F B J E U B V C J I C C B R D C [ U I d d I U D E C D [ W E C [ D R B F B R U E H I ] B I C I W W B \ U I _ d B F D [ � I [ [ E W D I U B R Q D U H W E J _ D C D C GU H B 0 : I C R 3 : B I F U H B d B W U F E R B [ S

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �52 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex C L . E C U D C V B R NC.1.3.1 Derivation of the 1 resistance criterion > H B a F B [ D [ U I C W B W F D U B F D E C D [ [ \ B W D K D B R D C E F R B F U E d D J D U U E I [ I K B d B ] B d U H B ` f @ � ] E d U I G B F D [ B E K U H B 3 :C B V U F I d D C U H B B ] B C U E K I K I V d U _ B U Q B B C I 0 : \ H I [ B I C R U H B U F I C [ K E F J B F U I C � E F W E F B S ; E F [ V W H I K I V d U � U H BW E C R D U D E C E K F I D [ B R \ E U B C U D I d E C U H B 3 : C B V U F I d Q D d d F B J I D C V C U D d U H B E \ B F I U D E C E K 0 : B I F U H K I V d U \ F E U B W U D E C S2 U D [ D J \ E F U I C U U E C E U D W B U H I U U H B a W F D U B F D E C D [ R B F D ] B R U E d D J D U U H B \ E Q B F K F B c V B C W Z ] E d U I G B F D [ B E K U H B 3 :C B V U F I d S > H B F B I [ E C K E F U H D [ [ \ B W D K D W I U D E C D [ U Q E K E d R OI N D U D [ Q B d d R E W V J B C U B R U H I U U H B H V J I C _ E R Z D [ B [ \ B W D I d d Z ] V d C B F I _ d B U E U H B B K K B W U [ E K ` f @ � W V F F B C UK d E Q D C G U H F E V G H D U ø T ù ³ I C R_ N D U D [ ] B F Z R D K K D W V d U U E F B [ U F D W U H D G H K F B c V B C W Z [ V F G B [ K F E J _ B D C G U F I C [ K B F F B R K F E J U H B 0 : U E U H B 3 :[ Z [ U B J S 6 E U H E K U H B B I F U H D C G [ W H B J B [ B J \ d E Z B R _ Z 4 [ � E J O W E J _ D C B R I C R [ B \ I F I U B R 0 : I C R 3 :B I F U H [ � I d d E Q K E F 0 : [ V F G B [ U E _ B U F I C [ K B F F B R U E U H B 3 : S > H D [ \ F I W U D W B D [ C E U W E C [ D R B F B R R I C G B F E V [G D ] B C U H B [ H E F U R V F I U D E C E K U H B R D [ U V F _ I C W B [ S ; V F U H B F � U H B H D G H [ V F G B D J \ B R I C W B E K U H B 3 : \ H I [ B [D C W E J \ I F D [ E C Q D U H U H I U E K U H B 0 : k 3 : B I F U H B d B W U F E R B R D W U I U B [ U H I U [ V F G B [ Q D d d C E U \ F E \ I G I U B K I F E C U EU H B 3 : [ Z [ U B J S> H B B K K B W U D ] B W D F W V D U K E F I 0 : \ H I [ B i U E i U F I C [ K E F J B F U I C � K I V d U D [ D d d V [ U F I U B R D C K D G V F B . S a S = E U D W B U H I U _ E U H U H B0 : d D C B D J \ B R I C W B I C R I C Z K I V d U D J \ B R I C W B H I ] B _ B B C C B G d B W U B R S

Figure C.1 – Effective circuit for the derivation of the 1 impedance criterion for combined electrodes > H B ] E d U I G B F D [ B E C U H B 3 : C B V U F I d V C R B F U H B W E C R D U D E C E K I \ H I [ B U E U I C � K I V d U D [ W I d W V d I U B R Q D U H U H B I D R E KK D G V F B . S a S > H B D J \ B R I C W B E K U H B W E J _ D C B R 0 : k 3 : B I F U H B d B W U F E R B D [ I [ [ V J B R U E _ B a S

ú û üý þ ÿ � � ý ý � �� � � � y u y � r p~ u w y n x u y� ý �� � � � � � � � � � � � � � � û � � � �� � � � � � � � � �

5 / . < 0 4 = > . 3 8 ? ? 2 ; 2 . 8 > 2 / = OCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �53 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex C L . E C U D C V B R N/ C I T T � : [ Z [ U B J Oæ� � � �� �5 �å 5� è� � �� � £ �   ¢� ¡ �� � �¢ � � � � ! " # ! £ �   ¢¦ � � £ � $$$$ %é

I C Rè� � � 5æ� � � ¢ � � � � ! " # !¦ � � £ �� � � ¢# ! $é%

? D J D d I F d Z � E C I C a a � : [ Z [ U B J O&' ( )* + , -. /01 2 3 4 5 5 5 6 ' 7 8 9 : 8 : ; 3 ; < 2 3 = : > > : ? @ A B = : 9 C D > E E ; E 9 : D B 2 @ A F @ G E < @ : A = : 9 < 2 3 C E H @ C D C < : D G 2 8 : < 3 A < @ E > < : ? 2 @ G 2E 2 D C E A C E I J 3 ; D J K 3 G < 3 F ? @ < 2 : D < F E A B 3 9 : = 8 3 9 C E A 3 A < 2 E 9 C LM NO P Q% 5 ��5 5 �R S T U V W X Y ( Z? 2 3 9 3 @ ; < 2 3 B 9 : D A F 9 3 ; @ ; < @ [ @ < I W @ A C Z \ E A F< @ ; < 2 3 F D 9 E < @ : A : = G D 9 9 3 A < = > : ? < 2 9 : D B 2 < 2 3 J : F I W @ A ; Z Y] ; ; D C @ A B B 9 : D A F 9 3 ; @ ; < @ [ @ < I < : J 3 ' ^ ^ ^ C E A F E = E D > < G > 3 E 9 @ A B < @ C 3 : = _ ; ` 3 a D E < @ : A X Y ( B @ [ 3 ; L& ä b c ° d e f g h ( ) i &4 < @ ; G > 3 E 9 = 9 : C < 2 3 E J : [ 3 G E > G D > E < @ : A ; < 2 E < 3 [ 3 A @ = < 2 3 j & k l & 3 E 9 < 2 2 E ; E A @ C 8 3 F E A G 3 E ; > : ? E ; ( ` < 2 3[ : > < E B 3 9 @ ; 3 : = < 2 3 l & A 3 D < 9 E > @ A < 2 3 3 [ 3 A < : = E j & 8 2 E ; 3 m < : m < E A n = E D > < ? @ > > ; < @ > > 3 H G 3 3 F < 2 3 C E H @ C D C ; E = 3< : D G 2 8 : < 3 A < @ E > Y 4 A 8 9 E G < @ G 3 ` 2 : ? 3 [ 3 9 ` < 2 3 @ A G > D ; @ : A : = j & > @ A 3 E A F = E D > < @ C 8 3 F E A G 3 ; < 3 A F ; < : 9 3 F D G 3 < 2 33 H < 3 A < : = l & A 3 D < 9 E > [ : > < E B 3 9 @ ; 3 E A F ( @ ; < E n 3 A E ; < 2 3 D 8 8 3 9 > @ C @ < = : 9 < 2 3 E 8 8 > @ G E < @ : A : = E G : C J @ A 3 F3 > 3 G < 9 : F 3 YC.1.4 Separation of LV and MV earths at transformer installations 1 2 3 2 E o E 9 F : = 2 @ B 2 < 9 E A ; = 3 9 8 : < 3 A < @ E > ; : A < 2 3 G D ; < : C 3 9 A 3 D < 9 E > @ A < 2 3 3 [ 3 A < : = E 8 : ? 3 9 = 9 3 a D 3 A G I G D 9 9 3 A <F @ ; G 2 E 9 B 3 < 2 9 : D B 2 < 2 3 j & k l & 3 E 9 < 2 @ ; > E 9 B 3 > I E [ 3 9 < 3 F J I < 2 3 D ; 3 : = ; 3 8 E 9 E < 3 j & E A F l & 3 E 9 < 2 ; Y 4 A E [ : @ F @ A B: A 3 2 E o E 9 F ` 2 : ? 3 [ 3 9 ` < 2 3 ; 3 8 E 9 E < @ : A : = < 2 3 j & E A F l & 3 E 9 < 2 3 > 3 G < 9 : F 3 ; @ A < 9 : F D G 3 ; E 2 E o E 9 F : = @ < ; : ? A Y1 2 3 2 E o E 9 F = 9 : C ; 3 8 E 9 E < 3 3 > 3 G < 9 : F 3 ; @ ; 9 3 E > @ o 3 F F D 9 @ A B 2 @ B 2 = 9 3 a D 3 A G I G D 9 9 3 A < F @ ; G 2 E 9 B 3 ; J I < 2 3 j & ; D 9 B 3E 9 9 3 ; < 3 9 ; Y p D 9 @ A B < 2 3 ; 3 < @ C 3 ; ` < 2 3 8 : < 3 A < @ E > : = < 2 3 < 9 E A ; = : 9 C 3 9 < E A n @ ; 9 E @ ; 3 F < : < 2 3 [ : > < E B 3 F 9 : 8 E G 9 : ; ; < 2 3j & 3 E 9 < 2 > 3 E F @ A F D G < E A G 3 E A F < 2 3 j & 3 E 9 < 2 3 > 3 G < 9 : F 3 @ C 8 3 F E A G 3 Y q @ B 2 < E A n 8 : < 3 A < @ E > ; ; < 9 3 ; ; < 2 3 @ A ; D > E < @ : AJ 3 < ? 3 3 A < 2 3 l & ? @ A F @ A B ; E A F < 2 3 < 9 E A ; = : 9 C 3 9 < E A n E A F G : 9 3 Y r [ 3 9 < @ C 3 G : A < @ A D 3 F @ A ; D > E < @ : A ; < 9 3 ; ; C E I> 3 E F < : < 9 E A ; = : 9 C 3 9 = E @ > D 9 3 Y

p r X s j 5 t 1 X l ] u u 4 v 4 X ] 1 4 r t LCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �54 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex C W X : A < @ A D 3 F ZC.1.4.1 Application of a neutral surge arrester ] ; D 9 B 3 E 9 9 3 ; < 3 9 @ ; G : A A 3 G < 3 F J 3 < ? 3 3 A < 2 3 j & A 3 D < 9 E > W < : ? 2 @ G 2 < 2 3 < 9 E A ; = : 9 C 3 9 < E A n @ ; J : A F 3 F Z E A F < 2 3 l &A 3 D < 9 E > < : > @ C @ < < 2 3 [ : > < E B 3 ; < 9 3 ; ; E G 9 : ; ; < 2 3 l & ? @ A F @ A B m < : m G : 9 3 @ A ; D > E < @ : A F D 9 @ A B j & E 9 9 3 ; < 3 9 F @ ; G 2 E 9 B 3 ; Y] ; < 2 3 @ C 8 D > ; 3 @ A ; D > E < @ : A > 3 [ 3 > : = E w ^ ^ & ; I ; < 3 C @ ; ' x n & ` < 2 3 A 3 D < 9 E > ; D 9 B 3 E 9 9 3 ; < 3 9 @ ; ; 8 3 G @ = @ 3 F ? @ < 2 E ( ) ` xn & 8 9 : < 3 G < @ [ 3 > 3 [ 3 > Y1 2 3 C E H @ C D C G : A < @ A D : D ; : 8 3 9 E < @ A B [ : > < E B 3 W j X r & Z : = E ; D 9 B 3 E 9 9 3 ; < 3 9 ? @ < 2 E 8 9 : < 3 G < @ [ 3 > 3 [ 3 > : = ( ) ` x n & @ ;x n & Y 1 2 3 A 3 D < 9 E > ; D 9 B 3 E 9 9 3 ; < 3 9 ? @ > > J 3 B @ A < : G : A F D G < @ = < 2 3 [ : > < E B 3 E 8 8 > @ 3 F E G 9 : ; ; @ < ; < 3 9 C @ A E > ; 3 H G 3 3 F ; xn & Y 4 A 8 E 9 < @ G D > E 9 ` > @ B 2 < A @ A B ; D 9 B 3 ; ? @ > > J 3 < 9 E A ; = 3 9 9 3 F < : < 2 3 l & A 3 D < 9 E > [ @ E < 2 3 A 3 D < 9 E > ; D 9 B 3 E 9 9 3 ; < 3 9 Y y : ? 3 9= 9 3 a D 3 A G I [ : > < E B 3 ; C E I E > ; : J 3 < 9 E A ; = 3 9 9 3 F < : < 2 3 l & A 3 D < 9 E > ` 2 : ? 3 [ 3 9 ` D A > 3 ; ; < 2 3 < E A n [ : > < E B 3 B 9 3 E < > I3 H G 3 3 F ; x n & < 2 3 2 @ B 2 @ C 8 3 F E A G 3 : = < 2 3 ; D 9 B 3 E 9 9 3 ; < 3 9 ? @ > > > @ C @ < < 2 3 3 H < 3 A < : = < 2 3 8 : ? 3 9 = 9 3 a D 3 A G I 8 : < 3 A < @ E >9 @ ; 3 : = < 2 3 A 3 D < 9 E > YC.1.4.2 Resistance of the MV earth electrode 1 2 3 A 3 D < 9 E > ; D 9 B 3 E 9 9 3 ; < 3 9 C E I ; D = = 3 9 F E C E B 3 = 9 : C : [ 3 9 2 3 E < @ A B @ = E ; D ; < E @ A 3 F [ : > < E B 3 : = C E B A @ < D F 3 B 9 3 E < 3 9< 2 E A x n & @ ; E 8 8 > @ 3 F E G 9 : ; ; @ < ; < 3 9 C @ A E > ; Y ] F E C E B 3 F ; D 9 B 3 E 9 9 3 ; < 3 9 C E I : 8 3 A m : 9 ; 2 : 9 < G @ 9 G D @ < Y 4 A < 2 3 > E < < 3 9G E ; 3 ` 2 @ B 2 8 : ? 3 9 = 9 3 a D 3 A G I [ : > < E B 3 ; C E I J 3 < 9 E A ; = 3 9 9 3 F < : < 2 3 G D ; < : C 3 9 Y] ; D ; < E @ A 3 F [ : > < E B 3 E G 9 : ; ; < 2 3 E 9 9 3 ; < 3 9 < 3 9 C @ A E > ; C E I E 9 @ ; 3 @ A < 2 3 3 [ 3 A < : = E = E D > < = 9 : C E j & 8 2 E ; 3 < : < 2 3< 9 E A ; = : 9 C 3 9 < E A n : 9 G : 9 3 Y 1 2 3 C E H @ C D C E > > : ? E J > 3 9 3 ; @ ; < E A G 3 : = < 2 3 j & 3 E 9 < 2 @ ; ; 8 3 G @ = @ 3 F < : 3 A ; D 9 3 < 2 E < < 2 3x n & > @ C @ < @ ; A : < G : C 8 9 : C @ ; 3 F @ A ; D G 2 E ; @ < D E < @ : A Y1 2 3 3 = = 3 G < @ [ 3 G @ 9 G D @ < D ; 3 F @ A F 3 < 3 9 C @ A @ A B < 2 3 D 8 8 3 9 > @ C @ < : A < 2 3 j & 3 > 3 G < 9 : F 3 9 3 ; @ ; < E A G 3 @ ; @ > > D ; < 9 E < 3 F @ Av @ B D 9 3 X Y ' Y

Figure C.2 – Effective circuit for the derivation of the MV earth impedance limit v : 9 E J : > < 3 F = E D > < = 9 : C E j & 8 2 E ; 3 < : < 2 3 < 9 E A ; = : 9 C 3 9 < E A n : A E ' ' n & ; I ; < 3 C ` < 2 3 [ : > < E B 3 F @ [ @ F 3 9 9 D > 3 : A< 2 3 G @ 9 G D @ < : = v @ B D 9 3 X Y ' B @ [ 3 ; Lz { |} ~� |} �| | |z z �| | |~ � � � � �� � � � � � �� � � � � � �� � � � � �� � �� � �� � � � �� � � � � � �� �� � � � �� � � � �� �

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p r X s j 5 t 1 X l ] u u 4 v 4 X ] 1 4 r t LCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �55 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex C W X : A < @ A D 3 F Zu @ C @ > E 9 > I ` : A E A ( ( n & ; I ; < 3 C L� � �� � � � �� � NOTE:

z p r w q o w v r w y n o p o � y w u t � � w � o u w w o � y o w p r y y r � � v v o w v w r x y n o w x u t q u x u � o q � w � p � u y u p § v u � t y r p u p ¢ ¢ § ¨ ° ¨ � � � y o x �y n o ° ¨ o u w y n w o � � � y u p � o x � � y p r y o ¾ � o o q ¢ ­ ­ � ¬ � � p � y n � � � u t � o � p v � � � w o } � � � y n o v u � t y � � w w o p y s r � t q � o t o � � y n u p « ­ { � � ru t t r s v r w ° ¨ o u w y n v u � t y r � o w u y � r p � y n o v u � t y t o � o t r p y n o ¢ ¢ § ¨ � � � y o x � � w u � � o q � � � � o � � v � � p � u t r s o w ° ¨ o u w y n w o � � � y u p � o� u t � o ¥   ­ �C.1.4.3 Resistance of the LV earth electrode 4 A < 2 3 8 E ; < @ < ? E ; G : C C : A < 2 E < l & A 3 < ? : 9 n ; ? 3 9 3 8 9 : < 3 G < 3 F = 9 : C 3 E 9 < 2 = E D > < ; J I > : ? G D 9 9 3 A < 9 E < 3 F = D ; 3 ; Y1 2 3 G 9 @ < 3 9 @ E = : 9 < 2 3 G : 9 9 3 G < : 8 3 9 E < @ : A : = < 2 3 ; 3 = D ; 3 ; = : 9 C 3 F < 2 3 D 8 8 3 9 > @ C @ < : A < 2 3 9 3 ; @ ; < E A G 3 : = < 2 3 l & 3 E 9 < 23 > 3 G < 9 : F 3 Y ] < < 2 @ ; < @ C 3 ` < 2 3 ; 8 3 G @ = @ 3 F [ E > D 3 : = ( ^ 8 9 : [ @ F 3 F > @ < < > 3 > 3 3 ? E I @ A < 2 3 3 [ 3 A < : = E A 3 E 9 < 2 = E D > < [ @ E E= E D > < @ C 8 3 F E A G 3 Y j : 9 3 9 3 G 3 A < > I ` = D ; 3 9 E < @ A B ; : A l & ; I ; < 3 C ; 2 E [ 3 J 3 3 A @ A G 9 3 E ; 3 F < : E G G : C C : F E < 3 B 9 3 E < 3 9> : E F G D 9 9 3 A < ; Y 4 A : 9 F 3 9 < : : J < E @ A E ( ^ ^ ] = E D > < G D 9 9 3 A < ` E ; @ ; E < I 8 @ G E > 9 E < @ A B : = l & = D ; 3 ; ` < 2 3 < : < E > G @ 9 G D @ <@ C 8 3 F E A G 3 @ A G > D F @ A B < 2 E < : = < 2 3 = E D > < C D ; < A : < 3 H G 3 3 F W ' w ^ & k ( ^ ^ ] h Z ' ` w Y 4 < @ ; G > 3 E 9 = 9 : C < 2 @ ; = @ B D 9 3 < 2 E <@ < @ ; A : < 8 9 E G < @ G E > < : ; 8 3 G @ = I E ; D = = @ G @ 3 A < > I > : ? 3 E 9 < 2 @ A B 9 3 ; @ ; < E A G 3 < : E ; ; D 9 3 : 8 3 9 E < @ : A : = < 2 3 ; 3 8 9 : < 3 G < @ [ 3F 3 [ @ G 3 ; D A F 3 9 3 E 9 < 2 = E D > < G : A F @ < @ : A ; Yr A 3 : = < 2 3 8 9 @ C E 9 I 8 D 9 8 : ; 3 ; : = l & A 3 D < 9 E > 8 : @ A < 3 E 9 < 2 @ A B @ ; < : 8 9 3 [ 3 A < < 2 3 F 9 E ; < @ G F @ ; 8 > E G 3 C 3 A < : = < 2 3 l &8 2 E ; 3 ; D A F 3 9 < 2 3 G : A F @ < @ : A : = E A j & k l & ? @ A F @ A B = E D > < Y ] ; @ < 2 E 8 8 3 A ; ` @ < @ ; E > ; : A : < = 3 E ; @ J > 3 < : ; 8 3 G @ = I < 2 39 3 ; @ ; < E A G 3 : = < 2 3 l & 3 E 9 < 2 > : ? 3 A : D B 2 < : 9 3 F D G 3 < : E ; E = 3 > 3 [ 3 > < 2 3 [ : > < E B 3 < 9 E A ; = 3 9 9 3 F < : < 2 3 l & A 3 D < 9 E > @ A< 2 3 3 [ 3 A < : = ; D G 2 E = E @ > D 9 3 Y4 A > @ B 2 < : = < 2 3 G : A ; @ F 3 9 E < @ : A ; F @ ; G D ; ; 3 F E J : [ 3 ` < 2 3 J E ; @ ; = : 9 < 2 3 D 8 8 3 9 > @ C @ < : A < 2 3 @ C 8 3 F E A G 3 : = < 2 3 l &3 E 9 < 2 @ ; G D 9 9 3 A < > I ; 3 < E < E [ E > D 3 E < ? 2 @ G 2 ; D = = @ G @ 3 A < = E D > < G D 9 9 3 A < ? @ > > = > : ? @ A < 2 3 3 [ 3 A < : = E A j & k l & ? @ A F @ A B= E D > < = : 9 j & 3 E 9 < 2 = E D > < 8 9 : < 3 G < @ : A < : : 8 3 9 E < 3 < @ C 3 : D ; > I Y 1 2 @ ; > @ C @ < G E A J 3 9 : D B 2 > I B E D B 3 F J I E ; ; D C @ A B < 2 E <E J : > < 3 F = E D > < : G G D 9 ; J 3 < ? 3 3 A < 2 3 j & ? @ A F @ A B E A F < 2 3 l & A 3 D < 9 E > 8 : @ A < Y t 3 B > 3 G < @ A B < 2 3 @ C 8 3 F E A G 3 : = < 2 3< 9 E A ; = : 9 C 3 9 ` < 2 3 C E H @ C D C l & 3 E 9 < 2 9 3 ; @ ; < E A G 3 G E A J 3 G E > G D > E < 3 F = 9 : C E ; @ C 8 > 3 G E > G D > E < @ : A : A < 2 3 j &A 3 < ? : 9 n Y 1 2 3 3 = = 3 G < @ [ 3 G @ 9 G D @ < : = < 2 @ ; G E > G D > E < @ : A @ ; 8 9 3 ; 3 A < 3 F @ A v @ B D 9 3 X Y _ Y

Figure C.3 – Effective circuit for the derivation of the LV earth impedance limit 1 2 3 = : > > : ? @ A B 3 H E C 8 > 3 @ > > D ; < 9 E < 3 ; < 2 3 8 9 : G 3 F D 9 3 = : 9 G E > G D > E < @ A B < 2 3 C E H @ C D C @ C 8 3 F E A G 3 : = < 2 3 l & 3 E 9 < 2 : = E' ' n & k w ^ ^ & < 9 E A ; = : 9 C 3 9 E ; ; D C @ A B < 2 3 j & 3 E 9 < 2 = E D > < 8 9 : < 3 G < @ : A @ ; ; 3 < < : 8 @ G n m D 8 E < w ^ ] Y u @ C @ > E 9G E > G D > E < @ : A ; G E A J 3 8 3 9 = : 9 C 3 F < : F 3 9 @ [ 3 E > > : = < 2 3 @ C 8 3 F E A G 3 > @ C @ < ; 8 9 3 ; 3 A < 3 F @ A 1 E J > 3 ( Y

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p r X s j 5 t 1 X l ] u u 4 v 4 X ] 1 4 r t LCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �56 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex C - Example: W X : A < @ A D 3 F Z 4 A = @ B D 9 3 X Y _ ` < 2 3 l & 3 E 9 < 2 9 3 ; @ ; < E A G 3 [ E > D 3 @ ; F 3 9 @ [ 3 F @ A : 9 F 3 9 < : : J < E @ A w ^ ] 3 E 9 < 2 = E D > < G D 9 9 3 A < : A E ' ' n &; I ; < 3 C L

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° ± ² ©³ ´ µ¶ · ¸© ª « ¬ ­® ¯­ ª ¶ ©¹º

ºººº»¼NOTE: � n o � u t � � t u y � r p � r v ¦ ¨ o u w y n w o � � � y u p � o � u t � o � � p � r w � r w u y o u � u v o y � v u � y r w r v � y r u � � r � p y v r w � u � � o u � r p u t � u w � u y � r p r vy n o � r � t w o � � � y � � � y � � � � � � u w � u y � r p � p y n o ° ¨ � � � � y u y � r p o u w y n � x � o q u p � o � ½ ¾ ¿ À � u p q � � � y n o � x � o q u p � o r v y n o ° ¨ ; = Á  � ½ ; = Á  �C.2 Other equipment p 3 9 @ [ E < @ : A : = < 2 3 C E H @ C D C 9 3 ; @ ; < E A G 3 [ E > D 3 ; = : 9 3 E 9 < 2 3 > 3 G < 9 : F 3 ; E < 3 a D @ 8 C 3 A < @ A ; < E > > E < @ : A ; : < 2 3 9 < 2 E A< 9 E A ; = : 9 C 3 9 ; = : > > : ? ; < 2 3 ; E C 3 8 9 : G 3 F D 9 3 E ; : D < > @ A 3 F @ A X Y ( Y w Y _ Y 4 A ; < 3 E F : = G E > G D > E < @ A B < 2 3 9 3 ; @ ; < E A G 3 < :E > > : ? = : 9 < 2 3 : 8 3 9 E < @ : A : = C E @ A 3 E 9 < 2 = E D > < 8 9 : < 3 G < @ : A ` ; 3 A ; @ < @ [ 3 3 E 9 < 2 = E D > < G D 9 9 3 A < 8 @ G n m D 8 ; 3 < < @ A B ; E 9 3 D ; 3 F YC.3 References 6 ( 7 j : : 9 3 ` à Y Ä Y X Y W ( ) Å ' Z Y u 3 8 E 9 E < @ : A J 3 < ? 3 3 A p @ ; < 9 @ J D < @ : A 1 9 E A ; = : 9 C 3 9 q @ B 2 & : > < E B 3 E A F l : ? & : > < E B 35 E 9 < 2 5 > 3 G < 9 : F 3 ; Y 5 ; n : C 1 à 4 < 3 G 2 A @ G E > 9 3 8 : 9 < t : Y ( ' _ k ' k ( i (6 ' 7 ] t u 4 k 4 5 5 5 u < F Å ^ L ( ) Å i ` 4 5 5 5 Æ D @ F 3 = : 9 ; E = 3 < I @ A ] X ; D J ; < E < @ : A B 9 : D A F @ A B Y6 _ 7 u ] t u ( ^ ' ) ' L ' ^ ^ ( ` 5 E 9 < 2 @ A B : = l : ? m & : > < E B 3 W l & Z p @ ; < 9 @ J D < @ : A u I ; < 3 C ; Y

p r X s j 5 t 1 X l ] u u 4 v 4 X ] 1 4 r t LCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �57 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex D - Calculation of earthing conductor cross-sectional areas W t : 9 C E < @ [ 3 Z1 2 3 C @ A @ C D C ; @ o 3 : = J E 9 3 : 9 @ A ; D > E < 3 F G : A F D G < : 9 ; < : J 3 D ; 3 F = : 9 3 E 9 < 2 G : A A 3 G < @ : A ; @ ; B : [ 3 9 A 3 F J I < 2 3= : > > : ? @ A B LW E Z < 2 3 C E H @ C D C E > > : ? E J > 3 < 3 C 8 3 9 E < D 9 3 9 @ ; 3 F D 9 @ A B < 2 3 = > : ? : = x ^ q o G D 9 9 3 A < \W J Z 8 9 E G < @ G E > G : A ; @ F 3 9 E < @ : A ; YD.1 Conductor temperature rise [1] 4 5 5 5 Å ^ 8 9 3 ; 3 A < ; E A 3 a D E < @ : A W @ A G > D F 3 F E ; 3 a D E < @ : A p Y ( Z ? 2 @ G 2 9 3 > E < 3 ; < 2 3 G 9 : ; ; m ; 3 G < @ : A E > E 9 3 E : = EG : A F D G < : 9 < : < 2 3 3 H 8 3 G < 3 F 9 @ ; 3 @ A < 3 C 8 3 9 E < D 9 3 E = < 3 9 < 2 3 = > : ? : = G D 9 9 3 A < = : 9 E ; 8 3 G @ = @ 3 F < @ C 3 YÇÈ ÉÈÊÊË ÌÍ Î ÏÐ ÏÐÑ ÒÓÏ Ô Õ ÖÕ× W p Y ( Z? 2 3 9 3 L4 @ ; < 2 3 9 Y C Y ; Y G D 9 9 3 A < @ A n ] \] @ ; < 2 3 G : A F D G < : 9 G 9 : ; ; m ; 3 G < @ : A @ A C C � \1 e @ ; < 2 3 C E H @ C D C E > > : ? E J > 3 < 3 C 8 3 9 E < D 9 3 @ A X \1 f @ ; < 2 3 E C J @ 3 A < < 3 C 8 3 9 E < D 9 3 @ A X W < E n 3 A E ; w ^ Ø X Z \1 Ù @ ; < 2 3 9 3 = 3 9 3 A G 3 < 3 C 8 3 9 E < D 9 3 : = C E < 3 9 @ E > G : A ; < E A < ; @ A X W G : A ; < E A < ; 8 9 : [ @ F 3 F E 9 3 E <' ^ X Z \Ù @ ; < 2 3 < 2 3 9 C E > G : 3 = = @ G @ 3 A < : = 9 3 ; @ ; < @ [ 3 > I E < 9 3 = 3 9 3 A G 3 < 3 C 8 3 9 E < D 9 3 1 Ù \Ù @ ; < 2 3 9 3 ; @ ; < @ [ 3 > I : = < 2 3 G : A F D G < : 9 E < 9 3 = 3 9 3 A G 3 < 3 C 8 3 9 E < D 9 3 1 Ù @ A k G C � \Ú Û @ ; ( k Û \< ° @ ; < 2 3 < @ C 3 : = G D 9 9 3 A < = > : ? @ A ; 3 G : A F ; \ E A F1 X ] y @ ; < 2 3 < 2 3 9 C E > G E 8 E G @ < I = E G < : 9 : = < 2 3 C E < 3 9 @ E > @ A Ä k G C � k X Y1 X ] y @ ; B @ [ 3 A J I < 2 3 3 a D E < @ : A L1 X ] y h w ` ( Å w ; 8 3 G @ = @ G 2 3 E < W @ A G E > k B 9 E C k Ø X Z ; 8 3 G @ = @ G ? 3 @ B 2 < W @ A B 9 E C k G C Ü Z1 2 3 E J : [ 3 = : 9 C D > E @ ; < 2 3 A ; @ C 8 > @ = @ 3 F < : LÐ×Ý W p Y ' Z? 2 3 9 3Ú @ ; < 2 3 G : A ; < E A < = : 9 < 2 3 C E < 3 9 @ E > @ A G > D F @ A B E 8 9 3 m F 3 < 3 9 C @ A 3 F G D 9 9 3 A < G E 9 9 I @ A B < @ C 3 E A F E B @ [ 3 AC E H @ C D C E > > : ? E J > 3 < 3 C 8 3 9 E < D 9 3 Y

p r X s j 5 t 1 X l ] u u 4 v 4 X ] 1 4 r t LCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �58 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex D W X : A < @ A D 3 F ZX E > G D > E < 3 F Ú m G : A ; < E A < ; = : 9 ; : > @ F G : 8 8 3 9 E A F G : 8 8 3 9 G > E F G : A F D G < : 9 ; = : 9 E _ ; = E D > < < @ C 3 E 9 3 8 9 3 ; 3 A < 3 F @ A< E J > 3 p Y (Table D.1 – Calculated K-constants for a 3 s fault time

Material Conductivity Þ *for a

¼ �fault

Maximum final temperature º � � � � º � � � » � � � | » º � � } � � � � ~þ ë � ñ � ì ì ñ � � ñ é ì ê � î î � � � � � � õ � ¼ õ ¼ � õ � � õ » � õ � ½ ½ õ ½ ø� � î î � ê é ñ ì � ë é ê � � � � � » � õ � ø õ ø º õ ¼ � õ ½ � � õ � ø õ ø ø� � î î � ê é ñ ì � ë é ê � � � � � ¼ � õ � � ¼ õ � ¹ õ ¹ » õ º � ¼ õ ø � õ º �ß � � ê ê � ñ ë ì � ë é � � � � õ º » õ º ¼ õ ¹ � º õ ø � ò ö î � ñ ë � ñ ë � ó � ê ó ð ñ é � ñ � � � ì � ë é � � é � · é í ë � ô ì ñ ö ñ ð ì �� � ñ í � ö ö ë ö î � ñ ë � ï � � � � � é ñ ë ì ê � � ì ê ë � � � �� � � î î � ö ñ í ñ � � ñ é ñ ë ë ö î � ñ ë � � ð � ñ ë � ë ó ñ � � º � � �| ÿ ñ é � ñ � � � ì � ë é ö é ë � ñ ë » � õ º � �} � ñ í � ö ö ë ö î � ñ ë � � ï ô � ñ � � ê � � � ê ë � � � � �~ µ � � ë é ï � � ñ ë ¼ � � � ñ � ì ê � î î � ï � � ñ ë � � ¼ � � ï ñ ê � � ì ê ë � � � � í � ë ó � ö � ê ñ é é í � é ì ì ñ ë ô � ë ó � ì �� � � � � � ê � � � � ì � ì ñ � ñ � � � ñ ô é ö ñ í � ö ö ë ö î � ñ ë � �1 2 3 ; 2 : 9 < < @ C 3 G D 9 9 3 A < 9 E < @ A B ; : = ; < 9 E A F 3 F E A F G : 8 8 3 9 m G > E F ; < 3 3 > G : A F D G < : 9 ; E ; 8 9 3 ; 3 A < 3 F @ A < E J > 3 ; i E A F i EE 9 3 F 3 9 @ [ 3 F D ; @ A B 3 a D E < @ : A p Y ' E A F Ú G : A ; < E A < ; < E n 3 A = 9 : C < E J > 3 p Y ( Y

D.2 Practical considerations 1 2 3 E 8 8 > @ G E < @ : A : = G : C 8 9 3 ; ; 3 F > D B ; : 9 3 H : < 2 3 9 C @ G ? 3 > F @ A B < 3 A F ; < : F 3 = : 9 C 3 E 9 < 2 @ A B G : A F D G < : 9 ; Y 1 2 3 8 : @ A <: = F 3 = : 9 C E < @ : A = : 9 C ; E A 3 > 3 G < 9 @ G E > ? 3 E n 8 : @ A < ? 2 @ G 2 @ ; C : 9 3 8 9 : A 3 < : 2 3 E < @ A B ? @ < 2 < 2 3 = > : ? : = G D 9 9 3 A < Y 4 < @ ;< 2 D ; A : < 8 9 E G < @ G E > < : E 8 8 > I E G : A F D G < : 9 : = G 9 : ; ; m ; 3 G < @ : A E > E 9 3 E > 3 ; ; < 2 E A W @ Z ( ' C C � = : 9 E ; : > @ F G : 8 8 3 9G : A F D G < : 9 ` : 9 W @ @ Z ( i C C � @ A < 2 3 G E ; 3 : = E ; < 9 E A F 3 F G : A F D G < : 9 YD.3 References 6 ( 7 u X u à 5 ] ] ] x L ( ) ) Š` p @ ; < 9 @ J D < @ : A à 3 8 : 9 < L ] > < 3 9 A E < @ [ 3 C E < 3 9 @ E > ; = : 9 D ; 3 E ; 3 E 9 < 2 @ A B < E @ > ; k > 3 E F ; @ A ; < 3 E F : =G : 8 8 3 9 @ A 2 @ B 2 < 2 3 = < E 9 3 E ; Y

p r X s j 5 t 1 X l ] u u 4 v 4 X ] 1 4 r t LCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �59 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex E - Recommended installation record and MV equipment commissioning sheet W t : 9 C E < @ [ 3 Z

E.1 Soil resistivity survey form

1) Installation reference 1.1)

Electrical address 1.2)

Project details

2) Soil resistivity survey results

2.1) Soil types Loams, garden soil

Clays

Clay, sand and gravel mixtures

Sand and gravel

Slates, shale and sandstone

Crystalline rocks

2.2) Soil resistivity measurement results

Probe spacing E W C Z Specific depth p h ^ ` Å E W C Z Tester reading à W Z Geometric factor K Ú h ' E Resistivity W C Z8 h Ã Ú ( ^ ` Å i ` ' Å' ( ` i ( ' ` x à_ ' ` w ( Å ` Å xx w ` ^ _ ( ` w '( ^ Å ` ^ i ' ` Å _( x ( ' ` ^ ) w ` ' x

p r X s j 5 t 1 X l ] u u 4 v 4 X ] 1 4 r t LCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �60 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex E W X : A < @ A D 3 F ZApparent resistivity graph � � �

Resistivity

Ohm-m

� � � � ô þ î ñ ê � � ð ´ ö ¶ � ¼ » º ½ ¹ � ø � � ¼ » ºþ î ê � ï � ê ý î ë ó ´ ö ¶ � õ � õ ½ � õ » ¼ õ � » õ � » õ � º õ ½ ½ õ » ¹ õ � � õ � � õ � ø õ ½ � õ � õ ½ � õ �t r 1 5 u L

p r X s j 5 t 1 X l ] u u 4 v 4 X ] 1 4 r t LCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �61 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex E W X : A < @ A D 3 F Z Responsible person W A E C 3 E A F ; D 9 A E C 3 Z W D A @ a D 3 k 4 p A D C J 3 9 Z á * Eskom employee/contractor

W < 3 > 3 8 2 : A 3 A D C J 3 9 Z W ; @ B A E < D 9 3 Z Date

E.2 Medium-voltage equipment commissioning sheet

1 Feeder:

2 Area:

3 Depot::

4 Installation reference:

4a Electrical address:

4b Physical address:

5 Installation details:

5.1 5 > 3 G < 9 : F 3 ; 3 > 3 G < @ : A L

E Z 5 > 3 G < 9 : F 3 X : A = @ B D 9 E < @ : A 1 2 9 3 3 8 : @ A < ; < E 9

l @ A 3 E 9

l m ; 2 E 8 3 r < 2 3 9 u 8 3 G @ = I L

p r X s j 5 t 1 X l ] u u 4 v 4 X ] 1 4 r t LCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �62 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex E W X : A < @ A D 3 F ZJ Z 5 > 3 G < 9 : F 3 F @ C 3 A ; @ : A ; 1 9 3 A G 2 F 3 8 < 2W @ A C 3 < 9 3 ; Z à E F @ E > > 3 A B < 2 ` là : F > 3 A B < 2 ;à : F ; 3 8 E 9 E < @ : At D C J 3 9 : = 9 : F ;G Z X : C C 3 A < ; L5.2

à 3 ; D > < ; : = 3 > 3 G < 9 : F 3 9 3 ; @ ; < E A G 3 < 3 ; < â i ( ` Å ã C 3 < 2 : F W @ = 9 3 a D @ 9 3 F ZDefinition Position Distance ́

ö ¶ Resistance ́

¶ { � � ô � �� � � � ô � ñ ë � õ � {� � � � ô � ñ ë � õ » {� | � � ô � ñ ë � õ º {� } � � ô � ñ ë � õ ½ { � � ô � ñ ë � õ ½ � {� ~ � � ô � ñ ë � õ ¹ {� � � � ô � ñ ë � õ � {

5.3 Ã 3 ; D > < ; : = 3 > 3 G < 9 : F 3 9 3 ; @ ; < E A G 3 < 3 ; < â = : D 9 8 : < 3 A < @ E > C 3 < 2 : F W @ = 9 3 a D @ 9 3 F Z

� ÷ ä � õ � ¹ � å ä � õ » ½ ½ ¹ � æ ô õ ø � ½ � ç ä � õ ¼ ø ½ � è ÷ é é é é é� ÷ ä � õ ½ � � � æ ô » õ � º � � � ê ä � õ ½ � ½ � è ä � õ � ¹ ¹ » � è ÷ é é é é é� ÷ ä õ � � ¹ � æ ô õ » � � ê ô ¼ õ ½ � ¼ ¹ � ç ä õ ø » � ë ÷ é é é é é� ÷ ä ½ õ º � � º � ê ô ¼ õ ½ � ½ � ç ä ½ õ � � � ¼ � ë ô � õ ¹ � � � è ÷ é é é é é� ´ ò ¶ � ´ ñ � ¶ ÷ é é é é é é é

p r X s j 5 t 1 X l ] u u 4 v 4 X ] 1 4 r t LCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �63 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex E W X : A < @ A D 3 F Z6.

5 a D @ 8 C 3 A < F 3 < E @ > ;ü ë � ñ é � � ð ñ � � � ë � � � � ë ñ é é ì � ´ ó � ü ¶ñ ï í � õ ö ñ · � ï ñ � � � ë � ìý � � î � ë ï � é � � · � � � � ë ñ é é ì ì ´ ó � ü ¶ñ ï í � õ ö ñ · � ï ï � é � � · � ìï � � ñ ë � � ð � ë í î ò � ñ � � ï � � ö � ì ë ñ � é � � ñ · ì¸ ê ë � � ð � � î ìþ � � ñ é ü � ìò � ñ � � ï � � ö � ê ñ î ñ ê � ë í þ ÷ é é é é é é · ¸ µ Responsible person W A E C 3 E A F ; D 9 A E C 3 Z W D A @ a D 3 k 4 p A D C J 3 9 Z á * Eskom employee/contractor

W < 3 > 3 8 2 : A 3 A D C J 3 9 Z W ; @ B A E < D 9 3 Z Date

p r X s j 5 t 1 X l ] u u 4 v 4 X ] 1 4 r t LCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �64 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex F - List of component and design drawings W t : 9 C E < @ [ 3 ZF.1 Standard component drawings relevant to the code of practice on earthing p 9 E ? @ A B A D C J 3 9 ; E A F F 3 ; G 9 @ 8 < @ : A ; : = ; < E A F E 9 F G : C 8 : A 3 A < ; 9 3 > 3 [ E A < < : < 2 3 G : F 3 : = 8 9 E G < @ G 3 : A j & E A F l &F @ ; < 9 @ J D < @ : A ; I ; < 3 C 3 E 9 < 2 @ A B E 9 3 8 9 3 ; 3 A < 3 F @ A < 2 3 = : > > : ? @ A B < E J > 3 L

Topic Drawing No. Description X : A F D G < : 9 ; p m p 1 m _ ( _ à 4 A ; D > E < 3 F G : 8 8 3 9 E A F G : 8 8 3 9 mG > E F ; < 3 3 > ? @ 9 3p m p 1 m _ ( _ ) í E 9 3 G : 8 8 3 9 ? @ 9 35 E 9 < 2 9 : F ; p m p 1 m _ ^ ) ( u 2 < ; ( m ' 5 H < 3 A F E J > 3 3 E 9 < 2 9 : Fp m p 1 m _ ^ ) ' u 2 < ; ( m ' 5 E 9 < 2 9 : F G : D 8 > 3 9 X : A A 3 G < : 9 ; p m p 1 m _ ^ w Å 1 9 E A ; = : 9 C 3 9 > @ A 3 < E 8p m p 1 m _ ^ à i u 2 < ; ( m ' X : A F D G < : 9 < : 9 : F G 9 @ C 8 3 FG : A A 3 G < @ : A E A F G 9 @ C 8 @ A B = 3 9 9 D > 3p m p 1 m _ ^ Å ' u 3 < ; G 9 3 ?p m p 1 m _ ^ ) _ 5 E 9 < 2 9 : F G > E C 8p m p 1 m _ ( ^ ( l @ A 3 < E 8p m p 1 m _ ( ^ ' u 2 < ; ( m ' X 9 @ C 8 @ A B > D Bt 3 D < 9 E > ; D 9 B 3 E 9 9 3 ; < 3 9 p m p 1 m _ ^ Å Å l & A 3 D < 9 E > ; D 9 B 3 E 9 9 3 ; < 3 95 a D @ m 8 : < 3 A < @ E > B 9 @ F p m p 1 m _ ^ x ) 5 a D @ m 8 : < 3 A < @ E > B 9 @ FX : A F D G < @ [ 3 G : A G 9 3 < 3 p m p 1 m _ ' ^ x X : A F D G < @ [ 3 G : A G 9 3 < 35 E 9 < 2 > 3 E F = E ; < 3 A 3 9 ; p m p 1 m _ ( ' ) Æ E > [ E A @ o 3 F ? @ 9 3 ; < E 8 > 3

F.2 Standard design drawings relevant to the code of practice on earthing 1 2 3 = : > > : ? @ A B ; < E A F E 9 F F 3 ; @ B A F 9 E ? @ A B ; E 9 3 9 3 > 3 [ E A < < : < 2 3 G : F 3 : = 8 9 E G < @ G 3 : A j & E A F l & F @ ; < 9 @ J D < @ : A; I ; < 3 C 3 E 9 < 2 @ A B Y

p r X s j 5 t 1 X l ] u u 4 v 4 X ] 1 4 r t LCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �65 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex F W X : A < @ A D 3 F ZDrawing No. Description p m p 1 m ^ i ' à u 2 < ; Y ( m ' 1 9 E A ; = : 9 C 3 9 â ; @ A B > 3 8 : > 3 C : D A < @ A Bp m p 1 m ^ i ' Å X : A A 3 G < @ : A ; = : 9 ; D 9 B 3 E 9 9 3 ; < 3 9 ;p m p 1 m ^ i _ à u 2 < ; ( m ' l & ] í X F @ ; < 9 @ J D < @ : A 3 E 9 < 2 @ A Bp m p 1 m ^ i w ' j & E A F l & 3 E 9 < 2 3 > 3 G < 9 : F 3 F 3 < E @ > ;p m p 1 m ^ _ x i l & ; D 9 B 3 E 9 9 3 ; < 3 9 @ A ; < E > > E < @ : A

NOTE: � w u s � p � � r v o u w y n � p � u w w u p � o x o p y � v r w r y n o w ° ¨ o � � � � x o p y ¥ � s � y � n � o u w � � � w � o u w w o � y o w � u p q � r x � o p � u y � p � o � � � � x o p yu w o y r � o v r � p q � p � � � �   � ¡ ¢ ¢ £ � � � � y w � � � y � r p � y u p q u w q � ¤ u w y � � � o � y � r p ¢ ¥ ¦ � � n y � r p q � � y r w � � u w y � � � t u w w o � � � w o x o p y � v r wr � o w n o u q t � p o � � � y r     § ¨ s � y n � r p q � � y r w � � � y r © u w o � r p q � � y r w �

p r X s j 5 t 1 X l ] u u 4 v 4 X ] 1 4 r t LCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �66 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex G – Impact Assessment W t : 9 C E < @ [ 3 ZImpact assessment form to be completed for all documents.

1 Guidelines î ] > > G : C C 3 A < ; C D ; < J 3 G : C 8 > 3 < 3 F Yî j : < @ [ E < 3 ? 2 I @ < 3 C ; E 9 3 t k ] W A : < E 8 8 > @ G E J > 3 Zî 4 A F @ G E < 3 E G < @ : A ; < : J 3 < E n 3 A ` 8 3 9 ; : A ; : 9 : 9 B E A @ ; E < @ : A ; 9 3 ; 8 : A ; @ J > 3 = : 9 E G < @ : A ; E A F F 3 E F > @ A 3 = : 9 E G < @ : A Yî X 2 E A B 3 G : A < 9 : > G : C C @ < < 3 3 ; < : F @ ; G D ; ; < 2 3 @ C 8 E G < E ; ; 3 ; ; C 3 A < ` E A F @ = A 3 G 3 ; ; E 9 I B @ [ 3 = 3 3 F J E G n < : < 2 3G : C 8 @ > 3 9 : = E A I : C @ ; ; @ : A ; : 9 3 9 9 : 9 ; Y2 Critical points

2.1 Importance of this document. E.g. is implementation required due to safety deficiencies, statutory requirements, technology changes, document revisions, improved service quality, improved service performance, optimised costs. X : C C 3 A < L p : G D C 3 A < 9 3 [ @ ; @ : A Y

2.2 If the document to be released impacts on statutory or legal compliance - this need to be very clearly stated and so highlighted. X : C C 3 A < L t : @ C 8 E G < J 3 I : A F 3 H @ ; < @ A B Y

2.3 Impact on stock holding and depletion of existing stock prior to switch over. X : C C 3 A < L t : @ C 8 E G < Y2.4 When will new stock be available? X : C C 3 A < L t k ]2.5 Has the interchangeability of the product or item been verified - i.e. when it fails is a straight

swop possible with a competitor's product? X : C C 3 A < L t k ]2.6 Identify and provide details of other critical (items required for the successful implementation

of this document) points to be considered in the implementation of this document. X : C C 3 A < L t : A 3 ? @ < 3 C ; Y2.7 Provide details of any comments made by the Regions regarding the implementation of this

document. X : C C 3 A < L X : C C 3 A < ? E ; : A < 2 3 = : 9 C E < : = < 2 3 F : G D C 3 A < ` < 2 @ ; ? E ; E F F 9 3 ; ; 3 F E A F < 2 3 9 3 ? E ; A : G : C C 3 A <: A < 2 3 < 3 G 2 A @ G E > F 3 < E @ > ; Y

p r X s j 5 t 1 X l ] u u 4 v 4 X ] 1 4 r t LCONTROLLED DISCLOSURE

DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �67 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex G W G : A < @ A D 3 F Z3 Implementation timeframe

3.1 Time period for implementation of requirements. X : C C 3 A < L 1 2 3 9 3 E 9 3 A : A 3 ? 9 3 a D @ 9 3 C 3 A < ; Y3.2 Deadline for changeover to new item and personnel to be informed of DX wide change-over. X : C C 3 A < L t k ]4 Buyers Guide and Power Office

4.1 Does the Buyers Guide or Buyers List need updating? X : C C 3 A < L t :4.2 What Buyer’s Guides or items have been created? X : C C 3 A < L t : A 34.3 List all assembly drawing changes that have been revised in conjunction with this document. X : C C 3 A < L t : A 34.4 If the implementation of this document requires assessment by CAP, provide details under 5 t :4.5 Which Power Office packages have been created, modified or removed? X : C C 3 A < L t : A 35 CAP / LAP Pre-Qualification Process related impacts

5.1 Is an ad-hoc re-evaluation of all currently accepted suppliers required as a result of implementation of this document? X : C C 3 A < L t :

5.2 If NO, provide motivation for issuing this specification before Acceptance Cycle Expiry date. X : C C 3 A < L 1 2 3 F : G D C 3 A < ? E ; 9 3 [ @ ; 3 F ` < 2 3 9 3 ? 3 9 3 A : G 2 E A B 3 ; @ A < 3 G 2 A : > : B I < 2 E < ? 3 9 3 @ A < 9 : F D G 3 F Y5.3 Are ALL suppliers (currently accepted per LAP), aware of the nature of changes contained in

this document? X : C C 3 A < L ï 3 ;

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DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �68 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

Annex G W G : A < @ A D 3 F Z5.4 Is implementation of the provisions of this document required during the current supplier

qualification period? X : C C 3 A < L ï 3 ;5.5 If Yes to 5.4, what date has been set for all currently accepted suppliers to comply fully? X : C C 3 A < L 1 2 3 9 3 ? 3 9 3 A : G 2 E A B 3 ; @ A < 3 G 2 A : > : B I Y5.6 If Yes to 5.4, have all currently accepted suppliers been sent a prior formal notification

informing them of Eskom’s expectations, including the implementation date deadline? X : C C 3 A < L 1 2 3 9 3 ? 3 9 3 A : G 2 E A B 3 ; @ A < 3 G 2 A : > : B I Y5.7 Can the changes made, potentially impact upon the purchase price of the material/equipment? X : C C 3 A < L t : Y5.8 Material group(s) affected by specification: (Refer to Pre-Qualification invitation schedule for

list of material groups) X : C C 3 A < L 5 E 9 < 2 @ A B 3 a D @ 8 C 3 A < E A F ; : = < ? E 9 3 Y6 Training or communication

6.1 Is training required? X : C C 3 A < L t : A 3 ? < 9 E @ A @ A B @ ; 9 3 a D @ 9 3 F = : 9 3 A B @ A 3 3 9 ; G D 9 9 3 A < > I D ; @ A B < 2 3 F : G D C 3 A < Y q : ? 3 [ 3 9 ` A 3 ?3 C 8 > : I 3 3 ; C E I 9 3 a D @ 9 3 < 9 E @ A @ A B Y6.2 State the level of training required to implement this document. (E.g. awareness training,

practical / on job, module, etc.) X : C C 3 A < L v : 9 A 3 ? 3 C 8 > : I 3 3 ; : A K : J < 9 E @ A @ A B @ ; 9 3 a D @ 9 3 F Y6.3 State designations of personnel that will require training. X : C C 3 A < L y 9 : K 3 G < 3 A B @ A 3 3 9 ; ` = @ 3 > F ; 3 9 [ @ G 3 ; ; < E = = E A F G : A < 9 E G < : 9 ; Y6.4 Is the training material available? Identify person responsible for the development of training

material. X : C C 3 A < L 1 2 3 F : G D C 3 A < ; 9 3 a D @ 9 3 F = : 9 < 9 E @ A @ A B E 9 3 < 2 : ; 3 @ A < 2 3 A : 9 C E < @ [ 3 9 3 = 3 9 3 A G 3 ; 8 > D ; < 2 @ ; ; < E A F E 9 F Y 4 =C : 9 3 @ A = : 9 C E < @ : A @ ; 9 3 a D @ 9 3 F < 2 3 A 1 2 E A F @ ? 3 t n E C J D > 3 E A F í 9 D G 3 j G l E 9 3 A G E A E ; ; @ ; < Y6.5 If applicable, provide details of training that will take place. (E.G. sponsor, costs, trainer,

schedule of training, course material availability, training in erection / use of new equipment, maintenance training, etc).

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DISTRIBUTION STANDARD: PART 2: EARTHING.

SECTION 1: MV AND LV DISTRIBUTION SYSTEM EARTHING

� � ! � � " # � � � � � � � $ �34-1985 � % & � �DST ' � ( � � � � � �0 ) � , � �69 of 69

ESKOM COPYRIGHT PROTECTED m n o p q r s p t r u q o q v w r x y n o z { | } m ~ � � y n � � q r � � x o p y � � � p � r p y w r t t o q u p q y n o w o � � r p � � � � t � y � w o � y � s � y n y n o � � o wy r o p � � w o � y � � � p t � p o s � y n y n o u � y n r w � � o q � o w � � r p r p y n o m ~ � �

X : C C 3 A < L 1 2 3 < 9 E @ A @ A B 9 3 a D @ 9 3 F @ ; : A K : J ` A 3 ? 3 C 8 > : I 3 3 ; ? : D > F E ; ; @ ; < 3 H @ ; < @ A B 3 C 8 > : I 3 3 ; : A 8 9 : K 3 G < ; E A FB 3 < 3 H 8 : ; D 9 3 < : < 2 3 F 3 ; @ B A E A F @ C 8 > 3 C 3 A < E < @ : A : = 3 > 3 G < 9 : F 3 ; D ; @ A B < 2 @ ; F : G D C 3 A < YAnnex G W G : A < @ A D 3 F Z

6.6 Was Technical Training Section consulted w.r.t module development process? X : C C 3 A < L t : Y6.7 State communications channels to be used to inform target audience. X : C C 3 A < L ð : 9 n B 9 : D 8 C 3 3 < @ A B ; E A F < 3 G 2 A @ G E > J D > > 3 < @ A ; Y7 Special tools, equipment, software

7.1 What special tools, equipment, software, etc will need to be purchased by the Region to effectively implement? X : C C 3 A < L 1 2 3 9 3 @ ; A : A 3 3 F = : 9 E F F @ < @ : A E > < : : > ; E A F ; : = < ? E 9 3 ` < 2 3 3 H @ ; < @ A B < : : > ; E A F ; : = < ? E 9 3 E 9 3 ; < @ > >E 8 8 > @ G E J > 3 Y

7.2 Are there stock numbers available for the new equipment? X : C C 3 A < L t k ]7.3 What will be the costs of these special tools, equipment, software?

t k ]8 Finances

8.1 What total costs would the Regions be required to incur in implementing this document? Identify all cost activities associated with implementation, e.g. labour, training, tooling, stock, obsolescence X : C C 3 A < Lñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ Yñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ Yñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ ñ Y4 C 8 E G < E ; ; 3 ; ; C 3 A < G : C 8 > 3 < 3 F J I Lt E C 3 L ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò òp 3 ; @ B A E < @ : A L ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò ò