Safety Rules for Working with HV Electricity - IDC … Rules for Working with HV Electricity ... IEC...
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Safety Rules for Working with HV Electricity
Hans Slagter Technical Marketing Executive
DEHN + SÖHNE
HV Design & Installation Forum
Brisbane 2013
5 Safety rules and Standards
Voltage Detectors, standards, test methods,
interferences fields and maintenance
Live working – Portable Earthing and short-circuiting
devices
Safety Equipment
1.
2.
3.
4.
5.
1. Disconnect completely
2. Secure against re- connection
3. Verify that the installation is dead
4. Carry out earthing and short-circuiting
5. Provide protection against adjacent live parts
Five safety rules
Switching sticks
Fuse tongs
Insulating
blades
Lock-out
systems
Phase comparators
Distance voltage detectors Voltage indicators
Voltage detectors
Earthing and
short-circuiting devices
Ball pins
Earthing
cartridges
E+S kits
Connecting
elements
3. Verify the installation
is dead
4. Carry out earthing
and short-circuiting
Standards – Operation of electrical installations
Five safety rules
4.
3.
Standards concerning voltage detectors
IEC 61243 standards
IEC 61243-3
Live working –
Voltage detectors
Two-pole low-voltage type
IEC 61243-1
Live working –
Voltage detectors
Capacitive type to be used
for voltages exceeding 1 kV a.c.
IEC 61243-2
Live working –
Voltage detectors
Resistive type to be used for voltages of
1 kV to 36 kV a.c.
IEC 61243-5
Live working –
Voltage detectors
Voltage detecting systems (VDS)
AS 2067: 2008 - Substations and high voltage
installations exceeding 1 kV a.c.
6.4.4 Devices for determining the de-energized state
Devices for determining that equipment is no longer energized
shall be provided, where required, taking operational requirements
into consideration……………
All devices supplied shall permit the de-energized state to be
checked at all points where the work is to be done and that have
previously been live, without danger for the operational personnel.
Either fixed equipment or portable devices (see IEC 61243) can be
used to meet this requirement.
ENA: 2009 - National guideline for management of tools
and equipment used in the electricity supply industry.
3.7 High voltage detectors and phasing units
3.7.1 Scope
This section applies to portable devices used for proving high
voltage electrical apparatus energised or de-energised, or phasing of
circuits
3.7.2 References
There is no Australian Standard which specifically covers High
Voltage detectors
Related information may be found in the following standards:
• IEC 61243-1: Live working – Voltage detectors - Capacitive type
to be used for voltages exceeding 1 kV a.c.
• IEC 61243-2: Live working – Voltage detectors - Resistive type
to be used for voltages of 1 kV to 36 kV a.c.
ENA: 2009 - National guideline for management of tools
and equipment used in the electricity supply industry.
3.7 High voltage detectors and phasing units
3.7.1 Description/specification
High voltage detectors used on systems subject to induced
voltages (such as double-circuit lines carrying high load currents)
should be able to discriminate between induced voltage and
system voltage – to prove conductors de-energised even if some
induced voltage is present.
Practical Use
Voltage Detectors in accordance
with IEC 61243
Capacitive type to be used for voltages exceeding 1 kV a.c.
Type PHE
Practical use of voltage detectors
IEC 61243-1
Practical use of voltage detectors
IEC 61243-2/A2
PHE/G II d.c. voltage detector
for d.c. links (ICE power car)
Resistive type to be used for voltages
up to 24 kV d.c
Practical use of voltage detectors
IEC 61243-3
two-pole voltage detector
with extension prods
Design of Voltage Detectors
Voltage Detectors in accordance
with IEC 61243
Voltage detectors acc. to IEC 61243-1 Design and
description of the individual parts
category L (line)
• Short test prod
• For overhead lines
category S (switch) • Long test prod
• For switchgear installations due to resistance to interference fields
• Also suited for overhead lines
separate type
must be attached to a suitably
rated insulating stick!
complete type
tested unit consisting of an
insulating stick, indicator and test
prod
Voltage detectors acc. to IEC 61243-1
Design and description of the individual parts
insulating clearance II
• Safety clearance
• Sufficient insulation
• Safe operation
hand guard
prevents slipping off or
contact with the
insulating element
handle
insulating clearance II
indicator
test prod with contact
electrode
• For distant parts of an installation
• For eliminating the influence of
interference fields
limit mark
red ring
Application of Voltage Detectors
Voltage Detectors in accordance
with IEC 61243
Voltage detectors acc. to IEC 61243-1 Application
Absence of supply voltage
Must be verified on all poles at the work
location or as close as possible to the work
location
Electrically trained and skilled
persons only
Nominal voltage /
Nominal voltage range Only use voltage detectors for the
nominal voltage specified on the name
plate!
Risk of: Incorrect indication
Arcing
Electric shock
Voltage detectors acc. to IEC 61243-1
Application
Work environment
For indoor use only
For indoor installations and outdoor
switching stations, also suitable for
use in wet weather conditions (e.g.
rain, snow, fog or dew)
Voltage detectors acc. to IEC 61243-1
Functional test
With self-testing element
Before and after each
use!
Attach voltage detector to a part of the
installation under operating voltage
Without self-testing
element
• Press the “Test“ button
(approx. 3 sec.)
• Acoustic signal 77 dB
• Red light flashes 50 000
Lux Outdoor type (1 000
Lux indoor)
• Release button
• Permanent green light
Voltage Detectors in accordance
with IEC 61243
Influence of Interference Fields
Influence of interference fields on voltage detectors
Effects without external voltage
Influence of interference fields on voltage detectors
Effects with external voltage
∆u < 10% U
∆u = U
Influence of interference fields on voltage detectors
Use in a phase opposition interference field
Different potential
in the coupling area!
Influence of interference fields on voltage detectors
Use in an in-phase interference field
Du = 0
category L category S
Influence of interference fields
Influence of interference fields on voltage detectors
with in-phase interference fields - Test set-up
category “S“
with extension
category “L“
without extension
Detector must be
removed from
service!
ENA: 2009 - National guideline for management of tools
and equipment used in the electricity supply industry.
3.7 High voltage detectors and phasing units
3.7.5 Tests – Acceptance
In addition to clause 2.2.1 for units that are not manufactured to a
recognised standard, the following tests should be performed to
ensure correct:
• Threshold voltage operation on all ranges – this could include
interference tests
• Visual and/or audible operation
• Operation of self test function
Pre-use - Prior to each use, the high voltage detector or phasing
unit shall be proved for correct operation. They shall also be
proved immediately after any “no indication” results
Influence of interference fields on voltage detectors
Calculation of the Threshold voltage range Ut in accordance with
IEC 61243-1
Sample calculation
UN = 20 kV (PHE3 20 S) 0.10 UN max < Ut ≤ 0.45 UN min
0.10 x 20 kV ≤ Ut ≤ 0.45 x 20 kV
2.0 kV ≤ Ut ≤ 9.0 kV
Possible range of Ut
0 kV 2.0 kV 9.0 kV
Sample calculation Switchable Type
UN = 11 ... 33 kV (PHE3 11 33 S) 0.10 UN max < Ut ≤ 0.45 UN min
0.10 x 33 kV ≤ Ut ≤ 0.45 x 11 kV
3.3 kV ≤ Ut ≤ 4.95 kV 0 kV 3.3 kV 4.95 kV
Influence of interference fields on voltage detectors
Calculation of the Threshold voltage range Ut
Sample calculation Switchable Type
UN = 11 ... 33 kV (PHE3 11 33 S) 0.10 UN max < Ut ≤0.45 UN min
0.10 x 33 kV < Ut ≤ 0.45 x 11 kV
3.3 kV < Ut ≤ 4.95 kV 0 kV 3.3 kV 4.95 kV
Sample calculation Switchable Type
UN = 11 ... 49.5 kV) 0.10 UN max < Ut ≤ 0.45 UN min
0.10 x 49.5 kV < Ut ≤ 0.45 x 11 kV
4.95 kV < Ut ≤ 4.95 kV 0 kV 4.95 kV
The ratio of 1:45
can not be exceeded!
Maintenance Test
Voltage Detectors in accordance
with IEC 61243
Maintenance test acc. to IEC 61243-1
General test procedure and documentation
Voltage detectors are to be tested
for compliance with the limit
values specified in the
Electrotechnical rules
The test intervals depend on the
conditions of use, frequency of
use, environmental conditions and
transport. However, test have to
be carried out at least every
6 years!
Tests are documented in a test
report and on the voltage
detector.
Health and safety legislation is
mandatory!
Maintenance test acc. to IEC 61243-1
Visual inspection, manual testing and measurements
Maintenance test acc. to IEC 61243-1
Measurement of the leakage current
earth electrode high-voltage electrode
hs
hand guard
red ring
Hs Height of the insulating
element of the divider
insulator
Test shall be considered
passed if leakage current:
Dry ≤ 50µA
Wet ≤ 0.5 mA
Maintenance test acc. to IEC 61243-1
Test for protection against bridging
bar A
bar B
Cu or Fe
Maintenance test acc. to IEC 61243-1
Test for protection against bridging
Maintenance test acc. to IEC 61243-1
Test for protection against bridging
Maintenance test acc. to IEC 61243-1
Test for clear indication – Category S
UN
(kV)
ao (mm)
category “L“
ae (mm)
category “S“
H
(mm)
D
Ø (mm)
d
Ø (mm)
1 < UN ≥12
12 < UN ≥ 24
24 < UN ≥ 52
52 < UN ≥ 170
170 < UN ≥ 420
100
270
430
650
850
300
1000
> 1500
> 2500
550
1050
60
100
>H
ring electrode ball electrode
D d
ae
UN
(kV)
ao (mm)
category “L“
ae (mm)
category “S“
H
(mm)
D
Ø (mm)
d
Ø (mm)
1 < UN ≥ 12
12 < UN ≥ 24
24 < UN ≥ 12
52 < UN ≥ 170
170 < UN ≥ 420
100
270
430
650
850
300
1000
> 1500
> 2500
550
1050
60
100
Maintenance test acc. to IEC 61243-1
Test for clear indication – Category L
>H
ball electrode ring electrode
D
ao
d
Maintenance test acc. to IEC 61243-1
Test for clear indication – Category L
Voltage Detectors in accordance
with IEC 61243
Marking of Voltage Detectors
Voltage detectors acc. to IEC 61243-1
Mandatory labels for indicators
• Manufacturer’s name or logo
• Symbol (double triangle)
• Nominal voltage and/or nominal voltage
ranges
• Nominal frequency and/or nominal
frequency ranges
• Type designation, production
number
• Category (S or L)
• Indication group
• Climatic category (C, N or W)
• Year of manufacture
• Date of the last maintenance test
• “Indoor“ or “outdoor“ use
Voltage Detectors in accordance
with IEC 61243
Withdrawal from Use
Voltage detectors acc. to IEC 61243-1
Withdrawal from use
The following voltage detectors exceeding 1
kV do not comply with EN/IEC 61243-1
No extension
Incorrect indication in an
in-phase interference
field!
No insulating clearance or
no marking of the insulating
clearance (no red ring)
Risk of electric shock!
Indicator in the
handle section
Illegible
rating plate
d.c. Voltage Detectors in accordance
with IEC 61243-2
Design
d.c. voltage detectors acc. to IEC 61243-2
Design of the PHE/G I voltage detector up to 24 kV d.c.
plug-in coupling
for extending the handle
limit mark
orange ring on test prod
test prod
with positive pole
test prod
with negative pole
Voltage detector for
contact wires with
additional earth-side
magnetic contact
insulating
clearance II
Selection and Design of Portable
Earthing
Earthing and Short-Circuiting Devices
in accordance with IEC 61230
ENA: 2009 - National guideline for management of tools
and equipment used in the electricity supply industry.
3.12 Portable earthing and protective bonding systems
3.12.2 References
There is NO Australian Standard which specifically covers portable
earthing systems. However IEC 61230: Live working – Portable
Equipment for Earthing or Earthing and Short-Circuiting is
considered the accepted industry reference.
ISSC14 Guide to electrical workers’ safety equipment
16 PORTABLE EARTHING SYSTEMS
16.2 References
There is no Australian Standard which specifically covers portable
earthing systems.
Related information may be found in the following standards:
• IEC 61230: Live working - Portable equipment for earthing
or earthing and short-circuiting
Ref: NSW Industry Steering Safety Committee, October 2010
Earthing and short-circuiting device
in accordance with IEC 61230
High-voltage and low-
voltage installations:
• Earth and short-circuit all
parts at the work location
• Connect earthing and short-
circuiting devices first to the
earthing system
• Earthing and short-circuiting
devices must be visible from
the all work location
Working procedure, General
Earthing and short-circuiting device in accordance with
IEC 61230
transformer station
high-voltage side
transformer station
low-voltage side
Earthing and short-circuiting device
High-voltage side – Calculation of the cable cross-section
Max. short-circuit current IK
for a duration tK of
1 s 0.5 s Cross-section
29.6 kA
23.7 kA
18,7 kA
13.8 kA
9.9 kA
6.9 kA
42 kA
33.5 kA
26.5 kA
19.5 kA
14 kA
10 kA
150 mm2
120 mm2
95 mm2
70 mm2
50 mm2
35 mm2
Short-circuit power SK“
Short-circuit duration tK
Nominal voltage UN
IK“ = (UN • 3 )
SK“ Formula for calculating the
short-circuit current IK
IK“ =
20 kV • 3
500 MVA = 15.43 kA
required cable cross-section: 95 mm²
SK“ : 500 MVA
tK : 1s
UN : 20 kV
Sample calculation
Earthing and short-circuiting device
High-voltage side – Cable cross-section table
Cable cross-section depending on the max. short-circuit current Ik and
the max. short-circuit time Tk and cable final temperature 250O C
10 s 5 s
Cross-section
of the copper
cable
1 000 A
1 600 A
2 200 A
3 100 A
4 400 A
5 900 A
7 500 A
9 400 A
1 400 A
2 200 A
3 100 A
4 400 A
6 200 A
8 400 A
10 600 A
13 200 A
16 mm2
25 mm2
35 mm2
50 mm2
70 mm2
95 mm2
120 mm2
150 mm2
2 s
2 200 A
3 500 A
4 900 A
7 000 A
9 800 A
13 200 A
16 700 A
20 900 A
1 s
3 200 A
4 900 A
6 900 A
9 900 A
13 800 A
18 700 A
23 700 A
29 600 A
0.5 s
4 500 A
7 000 A
10 000 A
14 000 A
19 500 A
26 500 A
33 500 A
42 000 A
Max. short-circuit current Ik over a duration of
Earthing and short-circuiting device
Low-voltage side
100
3.61
25
125
4.51
25
160
5.77
35
200
7.22
50
250
9.02
50
315
11.37
70
400
14.43
95
500
18.04
95
630
22.73
120
800
23.09
120
1000
28.87
150
nominal power of the
transformer (kVA)
short-circuit
current IK (kA)
cable cross-
section (mm2)
Calculation of the
cable cross-section IK“ =
(UN • 3 ) • uz[%]
SK“ • 100 %
1250
36.08
*
1600
46.19
*
2000
57.74
*
UN Nominal voltage
IK Short-circuit current
uz Short-circuit voltage
for example,
SK: 630 kVA
tk: 1s
IK“ = (400 V• 3 ) • 4
630 kVA • 100 %
IK“ = 22.7 kA
UN: 400 V
uz: 4%
Note: The low-voltage side is mostly
solidly earthed. Thus, earthing and short-
circuiting devices must have the same
cable cross-section.
max. short-circuit current
Flat / round conductor
Earthing and short-circuiting device
Selection and installation of ball pins
0.5 s 1 s Connection element
20 mm ball pin
25 mm ball pin
20
25
19.5 kA 13.8 kA
33.5 kA 23.7 kA
42 kA 29.6 kA *
* *
*
Installation of a ball pin as
connection point on a busbar
* only applies to straight ball pins from DEHN + SÖHNE
incorrect!
max. short-circuit current
Flat / round conductor
Earthing and short-circuiting device
Selection and installation of ball pins
0.5 s 1 s Connection element
20 mm ball pin
25 mm ball pin
20
25
19.5 kA 13.8 kA
33.5 kA 23.7 kA
42 kA 29.6 kA *
* *
*
Testing of ball pins
* only applies to straight ball pins from DEHN + SÖHNE
Earthing and short-circuiting device in accordance with
IEC 61230
Earth connection
element
Phase connection
element
Connection to the
earthing system
1.
2. Connection to the parts
to be earthed.
Visible from the work
location. Otherwise as close
as possible to the work
location!
Reduction of the cross-
section in case of a
compensated earthed
system
Earthing and Short-Circuiting Devices
in accordance with IEC 61230
Test currents and Markings
Test current - IEC 61230: Live working – Portable Equipment
for Earthing or Earthing and Short-Circuiting
• The a.c. component of the test current It shall be equal to 1,15 times the rated
current Ir ( It = 1,15 x Ir)
• The test first loop peak current Itm shall be not less than the a.c. component
of the test current multiplied by the peak current factor n ( Itm ≥ n x It )
Peak current factor n = 2.5 for 50 Hz and 2.6 for 60 Hz
Example: cable cross-section of 150 mm2, IK = 42 kA / 0.5 s
Itm ≥ n x It = 2.5 x 1.15 x 42 kA
Itm ≥ 120.75 kA
I tm
≥ n
x I
t
d.c. component of the current
Top envelope
Bottom envelope
Test current - IEC 61230: Live working – Portable
Equipment for Earthing or Earthing and Short-Circuiting
The earthing device itself or an additional non-removable label shall be
marked where appropriate with at least the following items of marking:
Manufacturer’s name or trade mark or assembler’s name;
Model or type reference for the device;
Year of manufacture;
Rated current Ir (kA), rate time tr (s) of the device and the value of the
rated peak factor n;
Number of the relevant IEC standard.
Markings
06.03.12/ 0000_E_1
Markings
Earthing and Short-Circuiting Devices
in accordance with IEC 61230
Maintenance Test
Earthing and short-circuiting device
Maintenance test
The employer must ensure that the
electrical installations and equipment is
checked for proper condition at regular
intervals.
The intervals must be chosen so that
the defects to be expected are detected
in time!
Occupational Health and safety
legislation is mandatory!
Earthing and short-circuiting device – Fatigue and
humidity penetration tests on cable with end fitting
60° 60°
10
axis of oscillation
cable guide to be tested
in the contacting cable
lug / connection element
copper cable
steel cable (6 mm)
Weight to obtain a resulting force =
0.5 N per mm2 of copper
Testing the efficiency of the
anti-kink sheath and the
corrosion resistance
01.07.2011 / 7059_E_1
1 000 cycles
Earthing and short-circuiting device – Tension test on
cable with end fittings
Each combination of cable to end fittings shall be tested using three test
samples – the force shall be applied for 30 sec.
Cross-sectional area
of conductor
Aa
mm2
Tension force
Copper
N
Tension force
Aluminium
N
≤ 50 100 x A 60 x A
≥ 50 80 x A 50 x A
a “A” = the rated cross-sectional area of the conductor
Example: 70 mm2 copper equates to a tension force N of : 80 x 70 = 5 600 N
Earthing and short-circuiting device
Removal from service
No compliance with IEC 61230
Cable cannot be visually inspected
for black colouration!
Sheath prevents visual
inspection!
Reduction of the cross-
section due to copper
corrosion
Conclusion
• Work Health and Safety Regulation 2011 which came into force 1st
Jan. 2012 has far reaching implications for employers regarding
safety, training and the use of approved equipment.
• All 5 safety rules must be adhered to before work can commence –
there are no short-cuts.
• Only approved safety devices in accordance with recognised
international or local standards must be used. If no local standard
exists then only IEC standards should be adopted in line with
Standards Australia's policy on recognising and adopting
international standards
• All non approved products should be removed and quarantined!
• All employers have a duty to ensure that the employees are
adequately training and that approved safety equipment is made
available!
DEHN+SÖHNE GMBH + CO.KG
PO BOX 290,
South Melbourne, VIC 3205
Australia
TEL. +613 8414 8277
Suite 13, Level 4, 150 Albert Rd
South Melbourne
HANS SLAGTER
Marketing Executive Australia
eMail: [email protected]
www.dehn.com.au