80251MV_HVsection1

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IndexDisconnectors and switchgear

SECTION 1Disconnectors and switchgear

1/3Introduction

Disconnectors IRW rocking post design range

IRW-DA – 11kV and 22kV, rocking post, line disconnectors Page 1/4

DA2 – 11kV, 400A Page 1/6

DA8 – 11kV and 22kV, 400A, 800A Page 1/7

DC2 – 11 and 22kV, 400A, Page 1/8

LA7 – 11kV double underhung disconnector, 400A, 630A Page 1/9

IRW-NL – 33kV, rocking post, line disconnectors Page 1/11

NL7 – 33kV, rocking post Page 1/13

NL77 – 33kV, 800A Page 1/13

NL78 – 33kV, with load break heads Page 1/13

IRW-N – 33kV, rocking post, station disconnectors Page 1/14

NG10 – 36kV, 400A, 13.1kA/3s Page 1/18

NN10 – 36kV, 800A, 26.3kA/3s Page 1/18

NH10 – as for NG, but with earth switch fitted Page 1/18

NJ10 – 33kV but with 44kV insulator for polluted or coastal sites Page 1/18

NP – as for NN, but fitted with Series EVR/E Earth switch Page 1/18

SG – 33kV, 400A, 13.1kA/3s, vertically mounted Page 1/19

SN – 33kV, 800A, 26.3kA/3s, vertically mounted Page 1/19

W – 33kV double upright bus section disconnector Page 1/19

YL2 – 33kV double underhung disconnector, 400A, 13.1kA/3s Page 1/20

YL7 – 33kV double underhung disconnector, 800A, 26.3kA/3s Page 1/20

YN – bus section option of – YL, above Page 1/20

Z – double underhung disconnector, 800A, 26.3kA/3s Page 1/20

IRW – drawings Page 1/21-41

IDW horizontal rotating design range Page 1/42

IDW-A – centre rotating disconnectors Page 1/42

AF – 22-66kV, 400/630/1000A, centre rotating, double break Page 1/47

AG – 66-110kV, 400/630A, centre rotating double break Page 1/48

IDW – drawings Page 1/49-50

Imported disconnectors Page 1/51

IndexDisconnectors and switchgear

1/2


1

Fusegear

Motor operators

Load breakequipment

Isolating links

Handles andoperatingaccessories

F – Fusegear Page 1/62

FI-DC27SP – 11kV switch-fuse Page 1/63

FI-D44 – 11kV switch-fuse Page 1/64

FI-NL77 – 33kV switch-fuse Page 1/65

FF-D – glass fuse tubes Page 1/66

HM-LA motor operator Page 1/71

LB – load break interrupters Page 1/75

LB-C24 – CEbreak load break interrupter Page 1/78

LB-Ezibreak – load break interrupter Page 1/79

LB-Z5 – summary of arc horn types Page 1/80

P Series – isolating links Page 1/81

PL-E_ – 11kV, flat face mounting Page 1/82

PL-H_ – 11kV, cross-arm mounting Page 1/83

PL-F_ – 22kV, flat face mounting Page 1/84

PL-J_ – 33kV, flat face mounting Page 1/85

PL-K_ – 33kV, crossarm mounting Page 1/86

H – accessories for disconnectors Page 1/87

HA – auxiliary switches Page 1/87

HF – insulating links Page 1/90

HG – pipe guides Page 1/90

HJ – mechanical interlock system for 110kV handles Page 1/92

HS-A – counter balance spring assemblies Page 1/93

HS-L – trip mechanism for fault trip throwers Page 1/94

Operating handles Page 1/95

Universal operating handle mounting strap Page 1/95

Mounts for operating handles Page 1/96

HR – operating handles Page 1/97

HV – operating handles Page 1/98

H – drawings Page 1/99

Earth switches E – earthing switches Page 1/53

EVF – J Series – 11kV earthing switches Page 1/55

ER-G – automatic earthing switches Page 1/56

ER-J – phase to phase fault thrower Page 1/58

E – drawings Page 1/59

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IntroductionDisconnectors and switchgear


1GeneralThe Canterbury Engineering division of Schneider Electric (NZ) has been designing and manufacturingdisconnectors and outdoor switchgear for over 90 years with a voltage range from 11kV to 220kV 50Hz.

We have an extensive range of rocking post designs as well as centre rotating double break, single sidebreak, vertical break and vertical close.

At 11kV and 22kV, we have a range of models of disconnector to meet most customer requirements forboth line and small substation applications – the IRW-DA2 and DA8 ranges.

At 33kV, for line applications and light substations, we have a reliable, low cost, lightweight 33kVdisconnector suitable for pole top mounting and with a rating suitable for distribution network usage – theIRW-NL7 range.

At 33kV, various configurations for substation designs are possible together with earth switches andbypass switches.

At voltages of 33kV and above, for larger new substations, we have a range of disconnectors that arewell suited to the modern low profile substation design. These same disconnectors may equally be usedin more traditional, pole structure type, switch yards.

We also have a range of disconnector models of older design which may be useful where customers wishto extend their substation while retaining the original ‘look’.

As well as disconnectors, we also supply a wide range of accessories.

Please also refer to the other outdoor substation sections of this catalogue, such as the structures andsupports section, for other related substation components.

Disconnector standard ratings availableRocking post type standard model disconnectors are available in the following voltage ratings: 11kV, 22kV, 33kV and 44kV.

These standard models are available with continuous current ratings that include 400A, 630A, 800A and1200A.

Short time ratings included as standard are:

Centre-rotating double break type standard model disconnectors are available in the following voltageratings: 66kV and 110/132kV.

These standard models are available with continuous current ratings of 630A.

The short time rating is 16kA for 3s.

Disconnector non-standard ratings availableA number of non-standard voltage and current ratings are available.

Please enquire for details.

Rated Short Time Currents:

Disconnector Model for 3s for 1s Peak withstand

IRW-DA2 8kA 12.5kA 31kA pack

IRW-DA8 16kA 25kA 40kA pack

IRW-NL7 16kA 25kA 40kA pack

IRW-DA – 11kV line disconnectors11kV rocking post type disconnectorsDesigned and manufactured in accordance with IEC standardsFlicker arc horns standard, or options with load break heads or wiping arc hornsReverse finger contacts

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1 Current carrying parts

ContactsThe wiping action fixed and moving contacts are made from hard drawn high conductivity copper sections,silver plated for optimum reliability.

The fixed contacts are of the reverse finger design.

Contact pressure is reinforced by heavy insulated phosphor bronze backing springs.

PantographsThe pantograph is made from flexible copper strand cable in black PVC sheathing with shrink sleavingapplied over the PVC sheath/compression lug boundary area and designed to provide maximumprotection in all service conditions.

All current carrying parts are electroplated for maximum reliability and aesthetic acceptability.

TerminalsThe terminal pads are horizontal with single 11mm diameter holes.

Options include multi-terminal clamps heavily tin plated and flowed for cable range of 6mm to 16mm diameter.

Load breakingThe disconnectors are supplied with standard flicker horns. Having a nominal load break capacity.

The disconnectors are available with load break heads for on-load breaking.

InsulatorsThe DA disconnectors use multi-shed solid core porcelain insulators, with conservative voltage ratings towithstand all normal service conditions:

DA2 Series uses nominal 15kV insulator IN-D3130 – BS3297:Part 3: 1982, Table 1, Level 2.

DA8 Series uses nominal 24kV insulator IN-D4130 – BS3297:Part 3: 1982, Table 1, Level 2.

c for Insulator technical details, please refer to the Insulator section.

These both have 2 bolt fixing provided on a hot dipped galvanised steel foot at both ends.

The porcelain finish is Munsell grey glaze.

Bases and bearersDA disconnector bases and bearers are of mild steel lipped channel section, hot dipped galvanised after fabrication.

The rocking insulator is hinged on a small diameter pivot pin for ‘seize free’ reliability.

The base assembly is fixed to the bearer channels by special clamps which slide in the base channel.This means that pole mounting and phase centres are variable within the limits of the base and beareroverall lengths. A rigid and secure 3 phase assembly is achieved when all clamps are tightened.

‘J’-bolts are provided with each switch for clamping the bearers to the pole top hardware (75-125mm grip).

Options

c Spar model disconnectors: galvanised mild steel RHS spars instead of channel bearers.

c ‘T’ type pole mounting brackets complete with suitable ‘J’-bolts.

c Line terminating straps for fitting to each base.

Load Break Maximum load break rating at: MV Catalogue

Interrupter Model 12kV 24kV 36kV page reference:

CE break 400A - - 1/78

Ezi break 630A 630A 200A 1/79

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IRW-DA – 11kV line disconnectors11kV rocking post type disconnectorsDesigned and manufactured in accordance with IEC standardsFlicker arc horns standard, or options with load break heads or wiping arc hornsReverse finger contacts


1AssemblyDisconnector may be supplied crated either:

c as phase assemblies, with bearers, etc. loose, for assembly and then mounting on site, or

c as three phase assembled units ready for mounting immediately on site.

In both cases, each phase is jig set and adjusted in our factory to minimise assembly time at site.The phase assemblies are connected by square section hollow tube axle which is easily slid into placewhen assembling. The clamp-on lever arm is adjustable along the axle.

The standard HV-B10 heavy duty operating handle (other options exist) provides a ‘pump’ type operation.The throw of the handle is adjustable.

Both the lever arm and handle provide for 20NB or 25NB pipe operation.

Optional extras include: earthing, pipe guide, and insulating connection for the operating pipe.

PackingFor phase assemblies: each phase assembly is individually placed in a carton and three cartons strappedtogether. Axle and bearers/spar are separately bundled.

For three-phase assembled disconnectors: the disconnector is individually crated, or crated with a second unit.

In both cases accessories such as pipe guide and operating handle are packed into a carton which ispacked into the disconnector crate..

Stocking of Disconnector PacksWe stock packs of frequently ordered disconnector models in our Auckland and Christchurch warehouses.

Each pack contains two disconnectors and their associated accessories, all in a timber crate and labelledwith the Pack’s unique stock code and list of contents.

Please contact us for more details.

SummaryThe DA2 disconnector is designed as an economic light duty switch for use with lighter fault duties andrural reticulation.

The DA8 disconnector (replaces the earlier DA7 range) is designed for rugged reliability at highercurrent ratings and with an insulation level for the most adverse conditions.

Please refer to the following pages for details of the models in these two disconnector series.

Also following are details of special switches and accessories in our 11kV disconnector range.

IRW-DA2 – 11kV disconnectors11kV, 400ADesigned and manufactured in accordance with IEC standardsFlicker arc horns standard, and available with load break heads or wiping arc hornsReverse finger contacts

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1 DA2 style – standard specification and featuresSpecification Description

Current rating Continuous 400A

Fault current Short time 150MVA for 3sRatings fault at 11kV 250MVA for 1s

31kA peak > 8kA for 3s> 12.5kA for 1s

Insulation level > 12kV IN-D3130 cylindricalpost insulator

Creepage distance 298mm

Phase centres Adjustable from 450 to 800mm

DA27 – standardSupplied with flicker arc horns, silver plated contacts, stainless steel bolts in the current path, and 3 phase assembled.

Model Description Reference Code

IRW-DA27 400A 00-03542-020 1830

IRW-DA27 400A With stainless steel 00-03542-025fasteners used throughout

IRW-DA27 400A Additional paint 00-03542-25P-ROTprotection over galvanised steel for Rotorua

IRW-DA26 400A With CEbreak, phase 00-03542-070assembled only

DA27R – spar modelSupplied with flicker arc horns, silver plated contacts, stainless steel bolts in the current path, and 3 phase assembled.


IRW-DA27R 400A 00-04460-020 1815

IRW-DA27R 400A With WIPING arc horns 00-04460-020TLC

IRW-DA26R 400A With CE break phase 00-04460-070assembled only

Raised spar feet (2 off) 94-05517

DA27E – economy modelFitted with flicker arc horns, plain copper contacts, galvanised bolts, and supplied 3 phase assembled.

Model Description Reference

IRW-DA27E Continuous 400A 00-03542-010

IRW-DA27ER Spar version P4737-20 spar replaces bearers 00-04460-010

DA27

DA27R

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IRW-DA8 – 11kV and 22kV disconnectors11kV and 22kV, 400/800ADesigned and manufactured in accordance with IEC standards.Flicker arc horns standard, or optionally with load break heads or wiping arc hornsReverse finger silver plated contacts and stainless steel fastenersMulti-terminals, heavy duty pump handle


1DA8 style – standard specification and featuresSpecification Description

Current rating Continuous 400A 800A

Fault current Short time 150MVA for 3s 300MVA for 3sratings fault at 11kV 250MVA for 1s 500MVA for 1s

> 8kA for 3s > 16kA for 3s> 12.5kA for 1s > 25kA for 1s31kA peak 40kA peak

Insulation level > 24kV IN-D4130 cylindrical post insulator

Creepage distance 381mm total115mm protected


DA87 – standardSupplied with flicker arc horns, silver plated contacts, stainless steel bolts in the current path, and 3 phase assembled.


IRW-DA87 400A 00-03150-010

IRW-DA87 Special as drg 3571 issue D 00-03150-010 S

IRW-DA87 400A Stainless steel 00-03150-015fasteners throughout

IRW-DA86 800A With CEbreak 00-03150-080

IRW-DA86 Coastal spec With CEbreak, stainless steel 00-03150-085 1831800A fasteners throughout

DA87R – spar modelSupplied with flicker arc horns, silver plated contacts, stainless steel bolts in the current path, and 3 phase assembled.


IRW-DA87R 400A 2.0m spar and flicker arc horns 00-04455

IRW-DA87R 400A 2.0m spar 00-04455-010

IRW-DA87R 400A 2.4m spar, 22kV 00-04455-014

IRW-DA87R 400A 2.7m spar 00-04455-017

IRW-DA87R 800A 300MVA, 3s 00-04455-020

IRW-DA87R 400A 150MVA, 3s with spar earth wire 00-04460-020

IRW-DA86R 400A With CEbreak, 150MVA only 00-04455-070

IRW-DA87R 400A 2.4m spar, load break provision 00-04455-100

IRW-DA883R 400A 2.4m spar, 22kV load 00-04455-114break provision

IRW-DA883R 400A 2.7m spar, 22kV, with provision 00-04455-117for load break heads

Ezibreak kitset c/w Load break interrupter 00-04449-003

Raised spar feet (2 off) 94-05517

DA87-std 800A

DA87R-spar 800A

IRW-DC2 – 11kV and 22kV disconnectors11kV, 400A, economical light duty switch, for use with lighter fault duties and rural reticulationDesigned and manufactured in accordance with IEC standardsFlicker arc horns standard, and available with load break heads or wiping arc hornsReverse finger contacts

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1 DC2 style – standard specification and featuresSpecification Description


Fault current Short time 150MVA for 3sratings fault at 11kV 250MVA for 1s


Insulation level > 12kV IN-D3130 cylindrical post insulators



DC27E – standard Fitted with flicker arc horns, plain copper contacts, galvanised bolts, and supplied 3 phase assembled.


IRW-DC27 400A 00-03554-020

IRW-DC27SP 400A Customer special, 00-03554-020SP 1824ref. drg 3790

IRW-DC26 400A With CEbreak, 00-03554-070phase assembled only

DC27E – economy modelSupplied with flicker arc horns, silver plated contacts, stainless steel bolts in the current path, and 3 phase assembled.


IRW-DC27E Continuous 400A 00-03554-010

DC27

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IRW-LA7 – 11kV disconnectors11kV, 400/630ADesigned and manufactured in accordance with IEC standardsReverse finger silver plated contacts and stainless steel fastenersMulti-terminals, heavy duty pump handle


1LA7 double underhung – standard specification and featuresSpecification Description

Current rating Continuous 400/630A

Fault current Short time 150MVA for 3sratings fault at 11kV 250MVA for 1s





LA7 – double under-hung disconnectorsC/w silver plated contacts, stainless steel bolts in the current path, in 3 phase assembly set.


IRW-LA72 400A c/w two 1.64m bearers 00-03171-020(supporting the three phase bases), lever arm assembly, and operating axle

IRW-LA72 630A c/w two 1.64m bearers 00-03171-025(supporting the three phase bases), lever arm assembly, and operating axle

IRW-DA73 400A c/w two 2.64m bearers 00-03171-030(supporting the three phase bases and outboard bearing), lever arm assembly, operating axle, and outboard bearing

IRW-DA73 630A c/w two 2.64m bearers 00-03171-035(supporting the three phase bases and outboard bearing), lever arm assembly, operating axle, and outboard bearing

c Please refer to the general arrangement drawing extracts on the following page for views of the IRW-LA7 double under-hung disconnectors.

c These views have been extracted from drawings MA3171 and MA3172.

LA7

IRW-LA7 – 11kV disconnectors11kV, 400/630ADesigned and manufactured in accordance with IEC standards.Reverse finger silver plated contacts and stainless steel fasteners,Multi-terminals, heavy duty pump handle.

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1 LA7 double underhung – views from drawings

c These views are intended to give an impression only of the LA7’s general arrangement. Pleasecontact us for more detailed and project specific information for your particular application.

LA7 - GA1

LA7 - GA2

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IRW-NL – 33kV disconnectors33kV rocking post type disconnectorsDesigned and built in accordance with IEC standardsAn economical light duty switch designed for single pole top mountingHowever, these disconnectors are also suitable for light duty rural substationsNote: The heavy duty, substation class, disconnectors are presented in later pages of this section.


1Current carrying parts

ContactsThe wiping action fixed and moving contacts are made from hard drawn high conductivity copper sections,silver plated for optimum reliability.

The fixed contacts are of the reverse finger design.

Contact pressure is reinforced by heavy insulated phosphor bronze backing springs.

All fasteners in the current path are stainless steel.

PantographsThe pantograph is made from flexible copper strand cable in black PVC sheathing with shrink sleavingapplied over the PVC sheath/compression lug boundary area and designed to provide maximumprotection in all service conditions.

All current carrying parts are electroplated for maximum reliability and aesthetic acceptability.

TerminalsThe terminal pads are horizontal with two 14mm diameter holes at 45mm centres to NEMA standards.

Options include multi-terminal clamps heavily tin plated and flowed for cable range of 12mm to 24mmdiameter; copper-aluminium bimetal transition plates; and galvanised or stainless steel high tensileterminal bolts.

The maximum horizontal terminal loading recommended not to exceed 0.75kN.

Load breakingThe IRW-NL77 disconnectors are supplied with standard flicker arc horns having a nominal load break capacity.

The IRW-NL78 disconnectors are supplied with load break interrupters for on-load breaking of up to 200Aat 33kV. (For higher ratings of load break interrupters, please contact us)

InsulatorsThe DA disconnectors use multi-shed solid core porcelain insulators, with conservative voltage ratings towithstand all normal service conditions:

NL7 Series uses nominal 36kV insulator IN-D3464 – BS3297:Part 3: 1982, Table 1, Level 2.

The IN-D3464 has 2 bolt fixing provided on a hot dipped galvanised steel foot at both ends.

The porcelain finish is Munsell grey glaze.

c for additional Insulator technical details, please refer to the Insulator section, page 7/1 onwards.

Bases and bearersNL7 disconnector bases and bearers are of mild steel lipped channel section, hot dipped galvanised after fabrication.

The rocking insulator is hinged on a small diameter pivot pin for ‘seize free’ reliability.

The base assembly is securely bolted to the bearer channels to give maximum rigidity. When bolted tobearers phase centres may be selected from 915mm, 1065mm or 1100mm mountings. ‘J’-bolts areprovided with each switch for clamping the bearers to the pole top hardware (75-125mm grip).

Options

c Spar model disconnectors: galvanised mild steel RHS spars instead of channel bearers.

c ‘T’ type pole mounting brackets complete with suitable ‘J’-bolts.

c Dead end mounting straps to enable line termination directly onto switch base.

IRW-NL – 33kV disconnectors33kV rocking post type disconnectorsDesigned and built in accordance with IEC standardsAn economical light duty switch designed for single pole top mountingHowever, these disconnectors are also suitable for light duty rural substationsNote: The heavy duty, substation class, disconnectors are presented in later pages of this section.

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1 AssemblyDisconnector are supplied crated

c as phase assemblies, with bearers, etc. loose, for assembly and mounting on site.

Each phase is jig set and adjusted in our factory to minimise assembly time at site.

The phase assemblies are connected by a square section hollow tube axle which is easily slid into placewhen assembling. The clamp-on lever arm is adjustable along the axle.

The standard HV-B10 heavy duty operating handle (other options exist) provides a ‘pump’ type operation.The throw of the handle is adjustable.

Both the lever arm and handle provide for 25NB pipe operation.

Optional extras include: earthing, pipe guide, and insulating connection for the operating pipe.

PackingEach phase assembly is individually cartoned and the three cartons strapped together. The axle andbearers/spar are separately bundled.

The pipe guide(s) and operating handle(s) are also packed separately.

Please refer to the following pages for details of the models in our IRW-NL7 line disconnector series.

(For heavy duty 33kV disconnectors, please refer to the later pages in this section describing the NG, NNand other substation class rocking post type 33kV disconnectors).

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IRW-NL7 – 33kV disconnectors33kV, 800ADesigned and built in accordance with IEC standardsFlicker arc horns standard, or optionally with load break heads or wiping arc hornsReverse finger silver plated contacts and stainless steel fastenersOptions of multi-terminals, stainless steel or galvanised fasteners, insulated operatinglink, etcSECTION 1

Disconnectors and switchgear

1NL7 style – standard specification and featuresSpecification Description


Fault current Short time 900MVA for 3s ratings fault at 11kV 1400MVA for 1s

BS 5253, > 16kA for 3s40kA peak > 25kA for 1s


Creepage distance 630mm total 200mm protected

Phase centres Choose from 1100, 1065, or 915mm

NL77 – standardSupplied with flicker arc horns, silver plated contacts, stainless steel bolts in the current path, and twinbearer channels.


IRW-NL77 800A Ref. drg MA3515 00-03515-010

IRW-NL77 400A Complete with wiping arc horns 00-03515-010TLC

IRW-NL77 800A All stainless steel fasteners 00-03515-015

IRW-NL782 800A With load break 00-03515-050

IRW-NL782H 800A c/w Ezibreak and stainless steel 00-03515-065fasteners, w/o bearer channels

NL77R – spar modelSupplied with flicker arc horns, silver plated contacts, stainless steel bolts in the current path, and spar.


IRW-NL77R 800A All stainless steel fasteners 00-03515-035

AccessoriesPlease refer to the section “handles and operating accessories” for NL7 accessories such as

c ‘J’-bolts, stainless steel ‘J’-bolts, pipe guides, operating handles, handle mounting straps, and raisedfeet for use with spar mounted disconnectors.

Please also refer to other sections of this catalogue for multi-terminals, T-bracket assemblies, bi-metaltransition plates, etc.

NL7

IRW-N station class – 33kV disconnectors33kV substation class, rocking post type disconnectorsDesigned and built in accordance with IEC standardsHeavy duty substation class switch series – NG10, NN10, NH10, NJ10, NP10, S, W, Y,YN, and ZThe new heavy duty disconnectors use the new IN-P4592, 36kV, station post InsulatorNote The older style insulators are available for modifications to existing substations

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1 Reliability and versatilityThe IRW-N standard heavy duty station class series of disconnectors includes a range of designs forupright, underhung, and vertical mountings. Current ratings range up to 2400A, with dimension andinsulator variations for 24kV, 36kV, and 52kV.

The design emphasis is on simplicity and reliability.

The switch components are delivered to site in sub assembly kits for economy, with detailed dispatch listsand assembly instructions provided.

Current ratingsThese disconnectors are manufactured in general compliance with IEC standards.

A conservative temperature rise of 35°C has been used in the design (compared with an allowable 65°Crise) at their continuous rated current. The designs allow the switches to safely withstand the effects of ashort time (3 seconds) through current of:

Continuous Short time400A 13.1kA and 16kA for 3s630A 13.1kA and 16kA for 3s800A 16kA and 26.3kA for 3s1250A 26.3kA for 3s1800A 26.3kA for 3s2400A 26.3kA for 3s

Design features

Insulators and voltage ratingsThe insulators used in the phase assemblies of these disconnectors must have 76.2mm (3.0 inch) PCDmounting to suit the base and top gear components.

The choice of insulator affects the voltage rating of these disconnectors, and you are referred to thecatalogue section: “7 – Insulators and Bushings” for specific information on the 24kV to 52kV range.

The standard insulator previously used (and still available for existing substation maintenance) has381mm (15 inches) overall height with cap and pedestal metalwork cemented to a deep skirt porcelaingiving substantial protected surfaces.

The present 36kV station post insulator, IN-P4592 (replacement for the 4494), is a cylindrical post type,with one piece porcelain, with 5 sheds, and with the cap and pedestals cemented over the porcelain ends(refer to the view on the left extracted from NZI drawing D687-0547/C).

Within the height (381mm) of switch insulator there are a number of alternatives available to suit specific needs.

Alternative insulators are available, having a self washing profile on a solid cylindrical porcelain. The morepopular of these alternative insulators has an overall height of 560mm (22 inches), to suit 36kVapplications under coastal salt deposits or other heavy pollution conditions.

Current carrying partsThese rocking post disconnectors have one insulator per phase mounted on a high strength aluminiumcast pedestal clamped to a three-phase operating axle, with the moving contact swinging in a verticalplane of the phase assembly.

Pantographs provide the electrical connection to the moving contact, and are either stranded copperconductors or laminated tinned copper strip assemblies. Lateral support and stability under through-faultcurrent conditions is an important factor of our designs.

In out rocking post disconnectors, contact closure provides a strong wiping action, which removes alldeposits, ensuring good current transfer.

The moving contacts are silver plated LG2 gunmetal castings.

Fixed contacts of 35 mm wide copper laminations carrying silver plated cast LG2 gunmetal contacts, withphosphor bronze laminations providing pressure on the line contacts.

4 holes tapped M12

IN-P4592

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IRW-N station class – 33kV disconnectors33kV substation class, rocking post type disconnectorsDesigned and built in accordance with IEC standardsHeavy duty substation class switch series – NG10, NN10, NH10, NJ10, NP10, S, W, Y,YN, and ZThe new heavy duty disconnectors use the new IN-P4592, 36kV, station post InsulatorNote The older style insulators are available for modifications to existing substationsSECTION 1


1Design features cont…

TerminalsElectrical connections each side of the disconnector are made using flat terminal pads whose dimensionsvary to suit the disconnector current ratings – as defined elsewhere in this section 1 of the catalogue.

Copper to aluminium transition plates or aluminium terminal pads can be supplied where warranted.

Where appropriate, the pantograph can be terminate directly onto the busbar, to provide economicalexpansion facilities, with busbar sliding support on the “back insulator” of the disconnector phase assembly.

Arc horns or load breakingStandard disconnector designs are fitted with wiping arc horns, to protect the main contacts, and to act asguides for contact entry on the higher current ratings.

Flicker arc horns or load break interrupters may be fitted when required (see the section on load breakslater in this section 1 of the catalogue).

BasesEach phase assembly has a hot dipped galvanised channel base having a four point mounting to commonthree phase bearer channels.

FastenersStructural connections – hot dip galvanised hex. bolts and nuts.

Current carrying connections – stainless steel bolts and nuts.

All connections are fitted with spring washers.

OperationsPlease refer to the section describing three phase arrangements elsewhere in this section 1 of the catalogue.

IRW-N station class – 33kV disconnectors33kV substation class, rocking post type disconnectorsDesigned and built in accordance with IEC standardsHeavy duty substation class switch series – NG10, NN10, NH10, NJ10, NP10, S, W, Y,YN, and ZThe new heavy duty disconnectors use the new IN-P4592, 36kV, station post InsulatorNote The older style insulators are available for modifications to existing substations

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1 Direct connection to busbarAlternative termination for substation installations using tubular busbars.

Pantograph clamped directly to bus tube with support angle for bus mounted on the fixed “back” insulatorof the disconnector.

Advantagesc eliminates an electrical joint face,

c provides expansion joint very economically.

Sketch key1. Disconnector pantograph,

2. Pantograph clamp to busbar,

3. Angle bus support – fixed or sliding,

4. Disconnector base assembly.

Generally available for all rocking post disconnectors. Variation is indicated by a change in the final twodigits of the series reference e.g. Series IRW-NG20.

Terminal padsSwitchgear terminal pad proportions must vary in size to suit the range of continuous or short timethrough current ratings.

Other variations occur because of the need to cope with direct aluminium bus terminations, special rigidbus fittings, etc.

Keeping the number of terminal pad variations down to the minimum is essential if production costs are toremain economical.

When ordering we suggest that you keep in mind that:

c standard sizes shown may be in stock,

c undrilled castings of the sizes shown are also stocked, shortening delivery times,

c other pad sizes incur pattern charges and longer delivery periods.

400A 1-bolt pad

630A 2-bolt pad

800A pads

Undrilled forspecial factory or customer site drilling as required.

Standard NZEdrilling, used in100x50 pad.

ANSI (NEMA)drilling in padwhere required.

1/17

IRW-N station class – 33kV disconnectorsIRW-N design range


1The IRW-N design rangeThe following pages illustrate the range of phase assemblies available within the 33kV, IRW design serieswhich are particularly suited to substation installations.

The rocking post disconnectors with wedge contacts are all known as Series IRW.

The fourth letter varies with major design changes.

The fifth letter and two digit suffix vary with ratings or minor design changes, accessories, etc.

Sketch key1. Standard support bearer spacing. An alternative bearer system exists for a range of substation

combinations – see description of Series IRW-NP.

2. Four mounting bolts M12 for rigid support at 178x966 centres on each phase base.

3. Height with standard pedestal post insulators 381mm tall with 76mm PCD mounting.

4. Wiping arc horns.

5. Terminal pads – see previous page.

6. Open position of disconnector rocking insulator and pantograph.

IRW-NG10c Standard rocking post disconnector.c For horizontal mounting on steel channel bearers.c Wiping arc horns.c Rated 36kV,

v 400A continuous,v 13.1kA for 3s short time.

c Alternative 630A available.

IRW-NN10c same base and insulators as NG10.c Rated 800A continuous,

v 26.3kA for 3s short time.

IRW-NH10c IRW-NG disconnector fitted with earth switch.c Earth switch rated 13.1kA for 3s.c Arm (1) swings parallel to disconnector phase base centreline.c Radius (R) will vary with insulator height but for 381mm pedestal post insulators, R is 483mm to tip of

moving contact.c Each moving arm (1) is connected via a tinned flexible braid to the 3 phase operating axle (2).c Fixed contact (3) is directly mounted on the disconnector fixed contact terminal pad.

IRW-NJ10c Fitted with 44kV cylindrical post insulator to suit polluted or coastal atmospheres.c Insulators 76mm PCD mounting with self washing profile and increased overall length of 560mm.c Larger insulator increases disconnector dimensions as shown.c Larger insulators may be applied to each of the other design types illustrated.

IRW-NPc IRW-NN disconnector fitted with EVR-E earth switch.c Both disconnector and earth switch rated 26.3kA for 3s.c Arm (1) swings at right angles to base.c Extended ‘D’ loop (2) allows line termination direct to disconnector base.c Offset base mounting centres (3) are standard to NZ Electricity designs and always used when this

type of earth switch is required.

IRW-NH10

IRW-NJ10

IRW-NP


1/18


1

1/19



1IRW-SIRW-SG10400 A 13.1kA for 3s,IRW-SN10800 A 26.3kA for 3s.c Vertical mounted switch.c Requires counterbalance spring or weight to assist operation.c M16 mounting bolts required (1).c Arc horns (2) different to horizontal.c All other details as for horizontal types NG10 and NN10.

IRW-Wc Double upright bus section disconnectors.c Allows both disconnectors to be maintained without having to deaden the whole substation.c Can be used as a double bus selector by making a central dropper connection at (1).

IRW-W

IRW-S


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1 IRW-Yc Double underhung disconnectors rated 400A continuous and 13.1kA for 3s.c Incorporate vertical dropper terminals (1) for connection to circuit breaker or recloser, to provide

for maintenance.c Can be supplied with pantographs incorporating terminal clamps for connection to tubular busbars (2)

or stranded line conductors (3).c Use with extension bar of appropriate length to maintain distance (4) to pantograph clamp.c When fitted with horizontal terminals, disconnectors can be connected (5) for use as double underhung

bus section switch.c Allows dropper connections (6) to metering transformers.

IRW-Zc Double underhung disconnectors rated 26.3kA for 3s.c Base mounting centres as for IRW-NP, as shown on a previous page.

IRW-YN

Bus section option – IRW-YN

1/21

Index - DrawingsFor IRW disconnectors and switchgear


1IRW-DA – 11kV and 22kV, rocking post, line disconnectors

DA2 and DA2-R – general arrangement drawings Page 1/22

DA8 and DA8-R – general arrangement drawings Page 1/24

DA – pole mount layout drawings Page 1/27

DC2 – general arrangement drawings Page 1/30

LA – underhung layout drawings Page 1/31

IRW-NL – 33kV, rocking post, line disconnectors

NL7 – general arrangement drawings Page 1/33

NL7 – vertical layout drawings Page 1/35

NL7-R – vertical layout drawings for spar mounted NL7 Page 1/37

FI-NL7 – general arrangement drawings – fuse/disconnector combo Page 1/38

IRW-N – 33kV, rocking post, station disconnectors

NG10 Page 1/18

NN10 Page 1/18

NH10 Page 1/18

NJ10 Page 1/18

NP Page 1/18

SG Page 1/19

SN Page 1/19

W Page 1/19

YL7 Page 1/39

YN Page 1/20

Z Page 1/20

IRW-DA drawings

IRW-NL drawings

IRW-YL7 – underhung layout drawings Page 1/39IRW-YL7

IRW-N drawings

IRW-DA2 – drawingsGeneral arrangement drawings of DA2 and DA2-R, 11kV disconnectors

1/22


1 From drawing MA3542, showing typical DA2 twin bearer disconnector switch.

The general arrangement drawing MA3542 shows views and sections of an IRW-DA2 type, 11kV, 400Adisconnector.

This is the standard twin bearer type arrangement, using ‘J’-bolts for fixing the switch to the structure byclamping the bearers to the hardwood or steel cross-arms. The galvanised steel twin bearers are suppliedwith the switch. However, the optional ‘J’-bolts, pipe guides, operating handles and other accessories havetheir own product reference codes and prices, and are sold separately.

If a motor operator (HM-LA) is used, the operating handle is not required as the HM-LA has its ownmanual operating handle.

1/23



1

The general arrangement drawing, 4460:4, shows an IRW-DA2-R type, 11kV disconnector with line sparfor direct attachment to the pole top.

For this type of switch, the twin bearers are replaced by the single spar. The single spar is bolted directlyto the side of the pole, as shown in the illustration from the IRW-DA-R drawing 4455:2, below. (The poleand braces required for mounting the Spar switch are the customer’s supply). Alternatively, ‘feet’accessories are available for mounting the spar switch onto the top of conventional, customer supplied,crossarms. This is the method shown above.

The extract from drawing 4455:2, on the left shows themounting of a typical IRW-DA-R model, 11kV, spar mount,disconnector, the 00-HG-PB50 pipe guide, and the 00-HV-B10operating handle.

NoteThe table at the top of the illustration on the left containsreference to IRW-DA7 type disconnector switches. The DA711kV rated disconnector has been superseded by the DA8,22kV rated, disconnectors. Please refer elsewhere in thiscatalogue for their details).

From drawings 4460:4 and 4455:2, showing typical DA2-R spar disconnector switch.


1/24


1 From drawing 4400, showing typical DA8 twin bearer, 11kV disconnector switch.

The general arrangement drawing 4400 shows views and sections of an IRW-DA8 type, 11kV, 400A and800A disconnector series.

This is the standard twin bearer type arrangement, using ‘J’-bolts for fixing the switch to the structure byclamping the bearers to the hardwood or steel cross-arms. The galvanised steel twin bearers are suppliedwith the switch. However, the optional ‘J’-bolts, pipe guides, operating handles and other accessories havetheir own product reference codes and prices, and are sold separately.


1/25



1

The above extract from the general arrangement drawing, 4454:8, shows an IRW-DA8-R type, 11kVdisconnector with line spar for direct attachment to the pole top.

For this type of switch, the twin bearers of the standard switch are replaced by the single spar. The singlespar is bolted directly to the side of the pole. (The pole and braces required for mounting the spar switchare the customer’s supply).

Alternatively, ‘feet’ accessories are available for mounting the spar switch onto the top of conventional,customer supplied, crossarms.

The illustration, above, shows the mounting of the 00-HG-PB50 pipe guide, and the 00-HV-B10 operatinghandle.

From drawing 4454:8, showing typical DA8-R spar, 11kV disconnector switch.


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1

The above extract from the drawing 4485 Series, shows the mounting details of an IRW-DA8-R type, 11kVdisconnector with spar for direct attachment to the top flange of a substation equipment “tall stand”.

The “tall stand” is fabricated from galvanised mild steel RHS.

The “tall stand” is bolted to the foundations by its bottom flange.

The illustration, above, also shows the mounting of the 00-HV-B15 operating handle.

From drawing 4485 Series, the illustration below shows a typical DA7-R spar, 11kV disconnector switchused inside an outdoor switchyard and mounted on a galvanised steel stand. Please refer to section 5,“Structures and supports”, for details of our range of substation equipment stands.

1/27

IRW-DA – pole mount layout drawingsLayout drawings for DA-R spar mount, 11kV disconnectors


1From drawing 4455:2, showing typical pole mounting layout details for DA-R spar mounted, 11kVdisconnector switch.

The extract from the spar mount layout drawing 4455:2, above, shows pole mounting views for the IRW-DA-R spar mount type, 11kV, 400A and 800A disconnectors.

This is the standard spar type arrangement, with the spar bolted directly to the pole. (The pole and bracesare the customer’s supply).

The optional pipe guides, operating handles and other accessories have their own product referencecodes and prices, and are sold separately.



1/28


1

The above extract from the pole layout drawing, 4455:24, shows an IRW-DA-R type, 11kV disconnectorwith 2.4m spar for direct attachment to a mid-pole position.

The single spar is bolted directly to the side of the pole. (The pole and braces required for mounting thespar switch are the customer’s supply).

The illustration, above, also shows the mounting of the 00-HG-PB50 pipe guide, and the 00-HV-B10operating handle.

From drawing 4455:24, showing DA-R, 2.4m spar, 11kV disconnector switch.

1/29



1From drawing E775 Series, the illustration below shows a DA-R spar, 11kV disconnector switch beingused as a overhead tie switch in an outdoor substation.

The illustration above, extracted from the drawing E775 Series, shows the mounting details of an IRW-DA-R type, 11kV spar mounted disconnector for use in an 11kV substation as an overhead tie switch.

IRW-DC2 – drawingsGeneral arrangement drawings of DC2, 11kV disconnectors

1/30


1 From drawing MA3554, showing typical DC2 twin bearer disconnector switch.

The above extract from the general arrangement drawing MA3554 shows views and sections of an IRW-DC2 type, 11kV, 400A disconnector, with an 8kA for 3s fault rating.

The DC2 model has only 6 insulators and was designed as an economical light duty switch for use withlighter fault duties and rural reticulation.

This disconnector model uses the standard twin bearer type arrangement, using ‘J’-bolts for fixing theswitch to the structure by clamping the bearers to the hardwood or steel cross-arms.

The galvanised steel twin bearers are supplied with the switch.

However, the optional ‘J’-bolts, pipe guides, operating handles and other accessories have their ownproduct reference codes and prices, and are sold separately.


1/31

IRW-LA – underhung layout drawingsLayout drawings for LA8 twin bearer, 11kV underhung disconnectors


1From drawing 3976, showing typical pole mounting layout details for LA8 twin bearer mounted, 11kVunderhungs with a DA8 disconnector switch.

The extract from the 11-22kV underhung disconnector layout drawing 3976, above, shows a side view ofa 2-pole mounting for the IRW-LA8 twin bearer underhung switches with a DA8 disconnector.

We can supply the LA8 and DA8 disconnectors complete with twin bearers, and supports. (The two polesare the customer’s supply).

The optional pipe guides, operating handles and other accessories have their own product referencecodes and prices, and are sold separately.

IRW-LA – underhung layout drawingsLayout drawings for LA8, 11kV underhung disconnectors

1/32


1 From drawing 3976, showing LA, 11kV underhung and DA8 disconnector switches.

The extract from the 11-22kV underhung disconnector layout drawing 3976, above, shows one side of afront view of a 2-pole mounting for the IRW-LA8 twin bearer underhung switches with a DA8 disconnector.

1/33

IRW-NL7 – drawingsGeneral arrangement drawings of NL7 and NL7R, 33kV disconnectors


1From drawing MA3515, showing typical NL7 twin bearer disconnector switch.

The general arrangement drawing MA3515 shows views and sections of an IRW-NL type, 33kV, 400 or800A disconnector.

This is the standard twin bearer type arrangement, using ‘J’-bolts for fixing the the switch to the structureby clamping the bearers to the hardwood or steel cross-arms. The steel twin bearers are supplied with theswitch. However, the optional ‘J’-bolts, pipe guides, operating handles and other accessories have theirown product reference codes and prices, and are sold separately.


IRW-NL7 – drawingsGeneral arrangement drawings of NL7 and NL7R, 33kV disconnectors

1/34


1

The general arrangement drawing, 4488:3, shows an IRW-NL7R type, 33kV disconnector with line spar fordirect attachment to the pole top. For this type of switch, the twin bearers are replaced by the single spar.

The single spar is bolted directly to the side of the pole, as shown above. (The pole and braces are thecustomer’s supply).

Alternatively, ‘feet’ accessories are available for mounting the spar switch onto the top of conventional,customer supplied, crossarms.

From drawing 4488:3, showing typical NL7R spar disconnector switch.

1/35

IRW-NL7 – vertical layout drawingsGeneral arrangement drawings of NL7, 33kV vertically mounted disconnectors


1From drawing MA3561, showing an NL7, 33kV twin bearer disconnector switch mounted verticallybetween two poles with an outboard bearing assembly and a Series HS-A10 balance spring.

The general arrangement drawing MA3561 shows views of an IRW-NL type, 33kV, 800A vertically mounted disconnector.

IRW-NL7 – vertical layout drawingsGeneral arrangement drawings of NL7, 33kV vertically mounted disconnectors

1/36


1

The extract above from the general arrangement drawing, 3561:3, shows an IRW-NL7 type, 33kVdisconnector with twin bearers for direct attachment to the pole top.

From drawing 3561:3, showing an NL7, 33kV, 800A, twin bearer, vertically mounted disconnector, withdetails of the pipe guide and operating handle.

1/37

IRW-NL7-R – vertical spar layout drawingGeneral arrangement drawing of NL7R, 33kV vertically spar mounted disconnector


1From drawing 4488:6, showing an NL7-R, 33kV spar disconnector switch mounted vertically onto one polewith a special 127x63 channel “Tee” bracket supporting the spar and matching the pole holes.

The “Tee” also provides a mount for the cable support cleat.

Note the counter balance weights mounted on the extended axle in order to clear the 2.4 m spar ends.

The above extract from general arrangement drawing 4488:6 shows views of an IRW-NL7-R, 33kVvertical, spar mounted, disconnector.

This an example of a layout design provided to meet a particular customer’s specification.

Please contact us for assistance with your line and substation layouts, for both new sites and formodifications to existing structures.

FI-NL7 – drawingsGeneral arrangement drawings of FI-NL7, 33kV fuse/isolator combination

1/38


1 From drawing 4167:2, showing a FI-NL7, 400A, 33kV fuse/isolator combination phase assembly with DINstandard fuses.

The general arrangement drawing 4167:2 shows an FI-NL77, 400A, 33kV fuse/isolator combination.

Multi-terminals, and either stainless steel or galvanised terminal bolts, are optional extras that aresupplied only if requested.

For further details, please contact us.

1/39

IRW-YL7 – underhung layout drawingsGeneral arrangement drawings of YL7 double underhung, 33kV disconnectors


1From drawing MA3632-1, showing typical YL7 double underhung disconnector switches fitted beneath aNL7 disconnector and all mounted on twin bearers.

The above extract from the general arrangement drawing 3632-1 shows a side view of an IRW-NL7 type,33kV, 400 or 800A disconnector complete with a pair of IRW-YL7 double underhung disconnectors fittedbeneath. This is the standard twin bearer type arrangement.

The galvanised steel twin bearers and fasteners are supplied with the switch phase assemblies forassembly on site.

Two “Tee” type bearer support steel work items can be provided as well for assembling onto andsupporting the completed arrangement to the two support poles. The twin bearers are bolted to pre-drilledholes in the “Tees”.

The twin bearer style of phase assembly support ensures a very rigid overall switch assembly.

The twin bearers combine with the phase bearer channels of both the NL7 and two YL7s, and with thetwo “Tee” steel bearer supports that are bolted to the two poles, to give a very robust “space frame” typeof construction.

Notec “Tee” bearer supports are not shown in the above illustration but are similar to those shown in other

drawings in this catalogue;c Poles would be the customer’s supply unless modern low level substation steel support structures are

required instead of conventional poles. (Please refer to section 5 for details).

The following page shows the NL7 and YL7 arrangement complete with pipe guides and operating handles.These latter items are basic, but optional, accessories that are listed in later pages of this catalogue.

IRW-YL7 – underhung layout drawingsGeneral arrangement drawings of YL7 double underhung, 33kV disconnectors

1/40


1

1/41

IRW-YL7 – underhung layout drawingsGeneral arrangement drawings of NL7, 33kV disconnector and a pair of YL7double underhung, 33kV disconnectors on a two pole structure


1

The illustration on the above is an extract from drawing 3632-2. It shows an NL7 and a pair of YL7s fittedonto twin, galvanised steel channel, bearers and two galvanised steel “Tee” supports in a two pole supportarrangement.

IDW-A – centre rotating disconnectors22kV to 66kV, and 110kV; 400A, 630A, and 1000A; short time rating of 16kA for 3sDesigned and built in accordance with IEC standards

1/42


1 SimplicityThis design of disconnector uses direct entry contacts, at each end of an arm which rotates rigidly withthe centre insulator.

Because the moving arm rotates parallel to the base, it is easy to use a wide variety of insulators, withoutthe added expense of special manufacturing variations.

Delivery to site is in sub-assembly kits, supported by detailed dispatch lists, and assembly instructions.

Current ratingsCurrent ratings include 400A and 630A, with 1000A available for bus switch applications.

Insulators and voltage ratingsThe insulators used in the phase assemblies of these disconnectors must have 76.3mm (3 inches) PCDmounting to suit the base and top gear components (1)*.

The choice of insulator affects the insulation coordination and voltage ratings of these disconnectors. Youare referred to the catalogue section 8 – “Insulators and bushings” for specific information on the 22kV to110kV insulators.

The table of dimensions given in this section is intended as a guide, to show typical available insulators.

Current carrying partsThese centre rotating double break disconnectors have a high conductivity copper tube arm (2), securedby cast gunmetal clamps (3), to the top of the rotating insulator (4).

The moving contacts are formed from the silver plated ends of the copper tube, with dimensions whichmatch the fixed IDW-A contacts (5) manufactured from purpose designed castings and 35mm widecopper with phosphor bronze laminations providing pressure on the contacts.

Contact closure provides a strong wiping action, which removes all deposits thus ensuring good current transfer.

Plain contacts are used on this Series IDW-A disconnector with appropriate restricted temperature rises at rated through-currents.

Stainless steel bolts are standard on all current carrying parts.

* Please refer to the diagram on the following page for details corresponding to the (1),etc., note marksto be found in the text, above.

1/43



1

The diagram and table, above, have been extracted from an earlier Canterbury Engineering publication.Hence, some of the features are out of date, such as the large shed insulators and tapered contacts onthe moving arms. However, the general principles of operation still hold.

The numbers are referred to in the text of this section.

The data in the table should be used as a guide only.

Please contact us for precise information for your particular project.

OperationsThe rotating insulator is carried on a cast gunmetal bearing unit (6), and is controlled by a lever arm (7)having inter-phase coupling rods connected at 305mm radius, with a rotation of 43 degrees either side ofthe base centre-line (i.e. moving arm opens to a maximum of 86° from the phase base centre-line – with aminimum opening of 72° recommended, for optimum isolator open gap distances).

When the bases are mounted vertically, the three phases can be conveniently operated by a pump typemanual handle (Series HV-PC).

With horizontal bases, it is more usual to use a torque tube operation with horizontal folding “walk around”handle (Series HR-B).

Table of standard dimensions (see note)

Rated voltage

Insulator centres (P)

Half mounting centres (H)

Half base length (B)

Minimum phase-phase centres

Insulator

Typical insulator height (N)

Typical terminal pad height (N=148)

Impulse withstand kV

Surface creepage distance

IN-P3444

381

529

200

720

Special

508

656

200

1015

IN-P3447

381

529

250

813

44kV

535

305

610

1220

IN-T3448

560

708

250

1092

50kV

610

424

685

1372

2 xIN-P3444

762

910

1440

IN-T3445

762

910

350

1829

33kV

460

305

535

1067

66kV

765

424

840

1675

can

use

44kV

or 6

6kV

arra

ngem

ents

Note: Where insulation co-ordination is required, this must be specified; and agreement reached on the appropriate dimensionsbefore starting manufacture.


1/44


1 TerminalsElectrical connections each side of the isolator are made using flat terminal pads (8).

The cast LG2 gunmetal terminal pads are tin plated and flowed, for use on either copper or aluminiumconductors.

Copper to aluminium transition plates can be supplied as optional extras where warranted for extraprotection with the use of aluminium conductors.

Arc hornsThe standard Series IDW-A disconnector or isolator may be fitted with double arc horns (9) (10) to giveimproved performance in the control of low power factor excitation currents, and to reduce wear andburning to the main contacts.

Use of flicker type arc horns (as compared with wiping type) allow a quicker arc extension and thus areduction in arcing time which is beneficial in situations where currents are relatively heavy and contactburning may expected to be a problem. However flicker arc horns will not increase the current interruptingrating of the disconnector.

BasesEach phase assembly has a hot dipped galvanised steel channel base (11) with four point mounting tocommon three phase bearers.

On this design, an optional aluminium structural alloy channel base can be supplied, where quantitieswarrant, for optimum coordination with aluminium alloy support structures.

Galvanised bolts are standard for bases, supports, operations, etc.

Optional features(1) One bolt (400A) or two bolt (630A) terminal pads.

(2) Supply of copper-aluminium transition plates for use on the terminal pads.

(3) Omission of the arc horns.

(4) Aluminium alloy channel base instead of hot dip galvanised channel base.

Purchasing specification(a) Voltage and insulation ratings – type of insulator.

(b) Whether insulation coordination is required.

(c) Required dimensions from the table of alternatives.

(d) Whether phase-phase bearers are required, instead of the normal situation where they are an integralpart of the structure.

(e) Current rating required, as well as the terminal pad size.

(f) Required operation items including handle.

(g) Required optional extras.

(h) Required accessory items such as terminal connectors, earthing switch, interlocks, auxiliary switches, etc.

1 bolt terminal pad 2 bolt terminal pad

1/45

IDW-A – centre rotating disconnectorsIDW-A design range – examples of 66kV switches


1

The view is extracted from drawing MA3408:1.

The disconnector and earth switch may be mounted on a 2.5m to 4.5m stand.

The disconnector may be manually operated with a HV-D operating handle, or with a HM-LA motor driven handle.


The disconnector may be mounted on a 2.5m to 4.5m stand.

The disconnector may be manually operated with a HV-D operating handle, or with a HM-LA motor driven handle.

IDW-AF4066kV, 630A, upright centre rotating disconnector, Series IDW-AF, with 76mm PCD insulators,complete with earth switch.

IDW-AF10066kV, 1000A, upright centre rotating bus disconnector, Series IDW-AF, with 76mm PCD insulators,complete with earth switch.

IDW-A – centre rotating disconnectorsIDW-A design range – examples of 110kV switches

1/46


1


The disconnector and earth switch may be mounted on a 2.5m to 4.7m stand.

The disconnector and the earth switch are manually operated with HV-D operating handles.

IDW-AG40110kV, 630A, upright centre rotating disconnector, Series IDW-AG, with 127mm PCD insulators,complete with earth switch.

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IDW-AF – 22-66kV disconnectors22kV to 66kV, 400/630/1000A switchesDesigned and built to IEC standardsCentre rotating double break, double flicker arc horns, reverse finger contacts, moving bladeMay be supplied with EVR-CE earth switch fittedThe earth switch is a vertical at right angles typeMay be supplied with stainless steel fasteners throughoutAll equipment is of New Zealand manufacture, assembly and test


1IDW-AFPlease contact us for a budgetary price, or for a firm quote, to suit your specific line or substation project requirements.

Specification Description

Current rating Continuous 400/630/1000A

System voltages 22kV through to 66kV

Contact breaks Two per pole Total length of break per pole to suit voltage rating

Fixed main Reverse finger type Silver plated copper, with phosphor bronze springs to maintain contacts contact pressure. Stainless steel fasteners

Moving contact Arc of 80 degrees Flicker type, stainless steel materials and fasteners

Fault current Short time fault 16kA for 3sratings 40 kA peak > 16kA for 3s, > 25kA for 1s

Insulation level > 24kV to > 72kV

IDW-AF – 22-66kV disconnectors, centre rotating, rated 400A to630A continuous, 16.0kA for 3s1000A bus switch also available.


IDW-AF10 400A MA3408:1, Drg 3916:_

IDW-AF20 400A c/w earth switch

IDW-AF30 630A

IDW-AF40 630A c/w earth switch

IDW-AF100 1000A bus switch Drg MA3408:100

IDW-AF – accessories, such as operating handles, motorisedhandles, and auxiliary switchesModel Description Reference

HV-D610 Operating handle, May be supplied withmanual, vertical pump type HA-AG11 fitted

HA-AG11 Auxiliary switch May be fitted to HV-D610

HM-LA61 Motor operator 24Vdc (110Vdc andOperating handle, motor driven 48/50Vdc options available)

EVR-CE – earth switches, rated 16kA/3s.Model Description Reference

EVR-CE Earth switch Rated at 16kA for 3s

Insulators: cylindrical post type insulators supplied to suit the system voltage, in grey glaze.

System voltages 22kV 33kV 50kV 66kV

Creepage distances (mm)Total 660 850 1200 1600Protected 250 310 465 590

Phase centres (mm) 1500 1500

The table above gives typical values for creepage distances and phase centres for our IDW-AF range ofdisconnectors.

Please contact us for an offer to suit your particular technical and environmental requirements.

IDW-AG – 66-110kV disconnectors66kV to 110kV, 400/630A switchesDesigned and built to IEC standardsCentre rotating double break, double flicker arc horns, reverse finger contacts, moving bladeMay be supplied with EVR-CE earth switch fittedThe earth switch is a vertical at right angles typeMay be supplied with stainless steel fasteners throughoutAll equipment is of New Zealand manufacture, assembly and test

1/48


1 IDW-AGPlease contact us for a budgetary price, or for a firm quote, to suit your specific line or substation project requirements.

Specification Description

Current ratings Continuous 400/630A

System voltages 66kV through to 110kV

Contact breaks Two per pole Total length of break per pole to suit voltage rating

Fixed main Reverse finger type Silver plated copper, with phosphor bronze springscontacts to maintain contact pressure. Stainless steel fasteners

Moving contact Arc of 80 degrees Flicker type, stainless steel materials and fasteners

Fault current Short time fault 16 kA for 3sratings 40kA peak > 16kA for 3s, > 25kA for 1s

Insulation level > 72kV to > 110kV

IDW-AG – 66-110kV disconnectors, centre rotating, rated 400A to630A continuous, 16.0kA for 3sModel Description Reference

IDW-AG10 400A Drg 3905:_

IDW-AG20 400A c/w earth switch

IDW-AG30 630A

IDW-AG40 630A c/w earth switch

IDW-AG – accessories, such as operating handles, motorisedhandles, and auxiliary switchesModel Description Reference

HV-D610 Operating handle, manual, May be supplied withvertical pump type HA-AG11 fitted

HA-AG11 Auxiliary switch May be fitted to HV-D610

HM-LA61 Motor operator: operating 24Vdc (110Vdc andhandle, motor driven 48/50Vdc options available)

EVR-CE – earth switches, rated 16kA/3sModel Description Reference

EVR-CE Earth switch Rated at 16kA for 3s

Insulators: cylindrical post type insulators supplied to suit the system voltage, in grey glaze.

System voltages 50kV 66kV 110kV

Creepage distances (mm)Total 1200 1600 1600Protected 465 590 590

Phase centres (mm) 1500 1500 2100

The table above gives typical values for creepage distances and phase centres for our IDW-AG range ofdisconnectors.

Please contact us for an offer to suit your particular technical and environmental requirements.

1/49

IDW-AF – drawingsGeneral arrangement drawings of IDW-AF 66kV, 630A disconnectors


1From drawing MA3408:1, showing a typical phase assembly of the IDW-AF, 66kV, 630A, upright centrerotating disconnector series.

The above extract from the general arrangement drawing MA3408:1 shows phase assembly views of anIDW-AF type, 66kV, 630A, upright centre rotating disconnector.

The disconnector is supplied phase assembled and with all the components necessary for mounting,including bearers and supports.

Also shown is an earth switch, type EVR-CE, rated at 26.3kA for 3s.

The disconnector is available with or without the earth switch.

The disconnector may be mounted on a stand between 2.5m and 4.5m high, according to the layout andrequirements of your substation.

The disconnector may be supplied with either a manual handle, type HV-D, or with a motor operator, typeHM-LA.

All steel work is hot dip galvanised.


Terminals may be supplied if requested.

The disconnectors are supplied with flicker type arc horns whose double action draws an arc to place aresistance in the circuit before the second flicker interrupts the current.

Please contact us for more details of our disconnectors and to discuss your precise switching requirements.

IDW-AG – drawingsGeneral arrangement drawings of IDW-AG 110kV, 630A disconnectors

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1

The above extract from the general arrangement drawing MA3905:4 shows phase assembly views of anIDW-AG type, 110kV, 630A, upright centre rotating disconnector.

The disconnector is supplied phase assembled and with all the components necessary for mounting,including bearers and supports.

Also shown is an earth switch, type EVR-CE, rated at 26.3kA for 3s.

The disconnector is available with or without the earth switch.

The disconnector may be mounted on a stand between 2.5m and 4.7m high, according to the layout andrequirements of your substation.

The disconnector and the earth switch may each be supplied with a manual handle, type HV-D.

All steel work is hot dip galvanised.


Terminals may be supplied if requested.

The disconnectors are supplied with flicker type arc horns whose double action draws an arc to place aresistance in the circuit before the second flicker interrupts the current.

Please contact us for more details of our disconnectors and to discuss your precise switching requirements.

From drawing MA3905:4, showing a typical phase assembly of the IDW-AG, 110kV, 630A, upright centrerotating disconnector series.

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Imported disconnectorsTo complement our range of New Zealand manufactureddisconnectors, we are able to import disconnectors


1In addition to our New Zealand manufactured range of disconnectors, we are able to offer a number ofranges of imported indoor and outdoor air break switchgear with voltage ratings up to 420 kV and currentratings up to 12,000 Amps.

The products include ranges for standard electrical distribution and transmission systems, and for railtraction systems.

The outdoor disconnector range includes vertical break, side break, centre break, centre rotating andsemi pantograph designs. These can be supplied with or without integral earth switches, and a range ofboth manual and motor operators are available.

Please contact us with your project requirements and we shall be pleased to prepare an offer for your consideration.

A centre break disconnector,type SR 16200, 52kV, 4000A.

A centre break disconnector,type SR 16200, 36kV, 2500A,with earth switch.

A toggle knife switch, type SB 813,7.2kV to 36kV, 1250A to 6000A

A vertical break disconnector, type17997, 52kV to 72.5kV, 630A to 2000A

Imported disconnectorsTo complement our range of New Zealand manufactureddisconnectors, we are able to import disconnectors

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1 The items shown on these two pages are typical of some of the disconnectors and associated equipmentthat we have supplied to New Zealand customers from overseas manufacture.

Please contact us with your particular application requirements and let us prepare an offer for you thatmeets the needs of your project.

Two views of a vertical closingdisconnector (semi-pantograph):type SP 16506, 36kV to 100kV, 800A to 2000A

A manual operator, type 70, lever,for vertical operating pipe, 400 N-m.

A manual operator, type R77,rotary lever, for verticaloperating pipe, 400 N-m.

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E – earthing switchesEarthing switches are used where a permanently installed facility isrequired for applying a positive connection to earth into an electricalsupply line, busbar, or equipment connection


1E Series earthing switchesE Series earthing switches are generally ganged three phase units with manual operation.

They can be fitted with an automatic operating handle for solenoid tripping; or with a motor drive whereremote operation is required.

Optional accessories include mechanical and electrical interlocks, auxiliary switches, and insulatedoperating linkages.

We manufacture a wide range of earthing switches, covering voltages up to 250kV dc to earth, andratings up to 52kA for 3 seconds through current. These include designs suitable for independentmounting or for installation on a compatible disconnector.

An earthing switch usually has a voltage and short time current rating matching the design performancelevels of the disconnectors and busbars for specific installations.

The most frequent application for earth switches is at substations, where they are used for busbar andline earthing, to create safe working conditions for staff during inspection, maintenance or repair.

Typical arrangement for a Series EVF 33kV earthing switch mounted on a 33kV 400A disconnector.

E – earthing switches

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1

Typical installation of a Series EIR/B independently mounted 33kV earthing switch, rated 26.3kA for 3.0seconds through current.

Design features include:

Insulated pivots and operations to prevent current flow, with consequential problems and dangers.

Phase-to-phase shorting bar to provide a fully rated star point connection from the earth switch movingarms, with provision for earthing connections (which also need to be fully rated as for the earthing switch)to this shorting bar from the local earth mat installation.

Type test reports give formal certification of performance, where such testing has been warranted.

Phase-to-phase operating rods counter-balance the moving arms for the larger earth switches (e.g. 220kVvoltage rating or 52.5kA / 3 seconds current rating) and on the underhung designs (e.g. 110kV SeriesEUR/A).

Guaranteed integrity of operating conditions can be provided, by means of comprehensive interlockingschemes, which can extend to the control of access doors, to ensure that equipment is isolated andearthed before access is possible.

An inquiry for earth switches should include the following information:

A Voltage rating and type of insulator

B Type of mounting preferred – and if disconnector mounted, type of disconnector and position relative todisconnector fixed contacts.

C Type of operation and its location relative to the three phases of the earth switch.

D Short time through current and its duration (maximum design values should be considered, includingoperation of back up protection relay systems).

E Whether interlocks are needed, and their extent.

F Whether a three phase shorting bar is required.

G Special features, auxiliary switches, interlocks, etc.

Typical 110kV underhung earthswitch Series EUR/A

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EVF-J Series – 11kV earthing switchesGanged 3 phase earth switch, able to be fitted to both new andexisting 11kV Series IRW-DA2 and IRW-DA8 disconnectors.Also available are design variations allowing use as an independentearth switch and for use with our 33kV IRW-NL7 disconnectors


1

SpecificationRated voltage 12kV

Phases 3, ganged

Short time current rating 13.1kA for 3 seconds

Operation manual, by pump type handle

Phase centres adjustable from 450mm to 800mm

Standards designed for compliance with BS5253-1975

Optional extrasMulti terminals – not normally regarded as part of earth switch,

Pipe guides for higher mounting applications,

Heavy duty pump type operating handle (with or without earth strap),

Insulated operating link in operating down rods,

Interlock to disconnector handle,

Interlock to equipment access door or gate,

Higher through-fault short time ratings than 13.1kA if required.

ER-G – automatic earthing switchesSimple and economically controlled single phase earthing switches for33kV supply lines, usually used for remote tripping of a breaker, aspart of a transformer protection system

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1 ER-G10

33kV pole mounted type

The 33kV automatic earthing switch (Series ER) consists of a counter-weighted earthing blade held in theopen position by a toggle linkage.

A solenoid plunger is mechanically connected to the toggle linkage.

Livening the solenoid trips the linkage, allowing the earthing blade to slam into its fixed contact.

An auxiliary switch in series with the solenoid opens the coil circuit, as the main contacts close, allowingthe trip signal to be obtained from contacts which remain closed.

ER-G20

33kV flat base mounting type

(The description for the ER-G20 is generally the same as for the ER-G10, above).

Note

We can supply alternative insulators to those shown in the illustrations.Please contact us for further details.

Please supply the following information when ordering:

A Quantity required,

B Mounting type (pole or horizontal base),

C D.C. voltage for the solenoid coil,

D Insulator required,

E Terminal type and size,

F Any special features.

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ER-G – automatic earthing switchesSpecification


1Typical specification for the ER-G Series earthing switches

Insulatorc Normally factory fitted,

c Standard design uses heavy duty 33kV cap and post insulator Series IN-P3447 having 287kV BIL,height of 381mm and surface creepage of 813mm (total).

c Alternatives are available – please contact us for details.

Earthing armc Single pole of a standard earthing switch having a nominal rating of 13.1kA for 3 seconds.

Terminalsc Supplied complete with terminal for line conductor – size and type of conductor to be stated, as well

as whether straight or right angle type terminal is needed (I.e. horizontal or vertical conductor entry).

c Earthing conductor is to terminate onto an M8 bolt passing through the frame and the arm earthing flex.

Solenoid (trip coil) auxiliary switchc Designed for a nominal 290VA, the coils are wound to order over a range from 24V (12A) up to

110V (2.5A).

c One pair of changeover contacts is available for customer use, with the standard design. The solenoidcoil is factory wired to its series auxiliary switch contact, within protective conduit.

Control cablec The auxiliary switch is supplied complete with removable gland plate, and a cable gland suitable for a

cable up to 11.8mm diameter (under armour).

Mountingc An alternative mounting design is available, having a horizontal base suitable for girder or beam

support – instead of the standard column mounting.

ER-J – phase-to-phase fault thrower33kV and 66kVExtracts from a drawing

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1

ER-J – phase-to-phase fault throwerSpring operated manual reset

For further information concerning the ER-J Series of phase-to-phase fault throwers, please contact us.

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EVF-J30 – drawingsGeneral arrangement drawings of EVF-J30 33kV earth switch


1

The above illustration is extracted from general arrangement drawing MA4194. It shows views and typicalarrangements for an EVF-J30 Series 33kV earth switch.

The earth switch is shown fitted on one side of the IRW-NL7.

The earth switch manual handle and operating mechanism is also shown.

The following two pages contain layout drawings of a two pole structure fitted with an IRW-NL7 3kVdisconnector, a pair of IRW-YL7 33kV underhung switches and an EVF-J30 Series earth switch.

From drawing MA4194, showing detail of a EVF-J30 Series earth switch.

EVF-J30 – earthing switch layout drawingsGeneral arrangement drawings of EVF-J30 33kV earthing switch

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1 From drawing MA4250-1, showing a two pole structure layout for a EVF-J30 Series earth switch fitted toan IRW-NL7 disconnector, with a pair of IRW-YL7 underhungs.

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EVF-J30 – earthing switch layout drawingsGeneral arrangement drawings of EVF-J30 33kV earthing switch


1From drawing MA4250-2, showing a two pole structure layout for a EVF-J30 Series earth switch fitted toan IRW-NL7 disconnector, with a pair of IRW-YL7 underhungs.

F – fusegearFusegear for 11kV, 33kV and 66kV, indoor and outdoor, applications

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1 IntroductionThe current range of CEC fusegear for 11kV, 33kV, and 66kV fuse assemblies all include the MESA HRC 45mm diameter DIN fuse clip.

This is a simple design for use outdoors or in a cubicle.

ConstructionBase Hot dip galvanised mild steel lipped channel, or channel.

Clip Base tin plated copper.

Clip MESA clip assembly.

InsulatorsTo suit the system voltage: Creepage distance:

11kV IN-C2804 298mm,

33kV IN-D3464 673mm,

66kV IN-T4588 1600mm.

All solid type cores.

Assemblies with insulators suitable for 3.3kV and 6.6kV installations also available.

MountingThe unit may be installed in either the upright, vertical or under-hung position.

When mounted vertically, the backstop must be in the lower position.

For under-hung mounting, the insulator must be inverted compared with the position shown in theillustration on the left. Please specify the application’s required mounting position when ordering.

Base dimensions vary according to the voltage. Please refer to the table below.

FusesThe fuse clips are for HRC DIN 45mm diameter fuses.

TerminalsThe fuse clips have 35mm wide by 4mm thick copper terminal pads with a single 13mm diameter hole ineach pad. Multi terminal connectors may be supplied as extras.

Type Description of HRC DIN std fuse mounts Productionreference

FF-SD45 11kV

FF-VA45 11kV, mounted on IRW-DA disconnector

FF-KM10 33kV

FF-L 66kV

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FI-DC27SP – 11kV switch-fuse11kV switch-fuse, FI-DC27SP, for customer supplied drop-out fuses


1FI-DC27SP1. A two insulator switch with an extended base for drop-out fuse mounting.

The switch rating is the same as an IRW-DA27, i.e. 400A continuous, 8kA for 3 seconds, 12.5kA for 1 second.The insulator is the IN-D3130 15kV porcelain.Contacts are silver plated.

2. The lipped channel bearers may be fixed directly to pole scarf.

3. The pantograph cable is bolted directly to the drop-out terminal plate.

4. The 11kV drop-out – customer’s supply.

5. The phase base is drilled to suit the customer’s drop-out.

Please specify drop-out make and dimensions at time of ordering.

The top lever arm is positioned at the front of the switch.

The extended phase base.

HG-PB50 pipe guide.

With the top lever arm to the front, the operating handle is still pulled down to open, as standard.

FI-D44 – 11kV switch-fuse11kV switch-fuse, FI-D44, type 45, for HRC DIN fuses

1/64


1 The FI-D44, type 45, 11kV switch fuse is rated at 400A and 8kA for 3 seconds STR.

The MESA fuse clip is for a HRC DIN std with 45mm diameter fuse ferrules.

Insulators are our IN-D4130 as used in our IRW-DA87 disconnectors.

The contacts are silver plated with all stainless steel fasteners in the current path.

The switch fuses are delivered as phase assemblies only, for three phase assembly at site or in your depot.

The operation as shown in the illustration requires a non-standard upward movement of the pipe andoperating lever to open the switch.

This may be reversed if the lever is positioned forward, in front of the switch, instead of towards the poleas in the illustration.

This latter arrangement would allow the use of a standard HV-B10 operating handle.

The usual accessories include:‘J’-Bolts, if bearers are to be clamped to cross-arms,HG-PB50 pipe guide,HV-B10 operating handle,11kV HRC DIN fuses.

Below is a front view of the three phase assembled FI-D44, type 45, switch fuse that shows the position ofthe operating lever between two of the phase assemblies.

Operating leverwith extensionshown fitted

M16 bolts through the pole suppliedby the customer

1/65

FI-NL77 – 33kV switch-fuseFI-NL77


1FI-NL7 fuse-disconnector combination33kV type, based upon the IRW-NL7 disconnector, and combined with the MESA HRC 45mm diameter DIN fuse clip.

NL7 disconnectorFlicker arc horns,

400A main contacts,

1 pantograph conductors.

IN-D3464 Insulators,

Fuse assemblyAs per 33kV HRC DIN fuse details on page 1/67.

AccessoriesHG-PB50 pipe guide, required if switch height exceeds 4.0m.

HV-B10 operating handle.

Operation balance springAvailable if required.

Operating pipe20NB galvanised steel operating pipe supplied by customer.

Refer to page 1/38 for IRW-NL7 fuse-switch combination general arrangement drawings.

The illustration below is extracted from drg 3653, and shows the front view of an FI-NL7 fuse-disconnector combination.

FF-D – glass fuse tubesReplacement 11kV glass fuse tubes, for use in customers’ existing FF-D 11kV fuse mounts

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1

IntroductionThe Series FF-D 11kV fuse mounts with glass fuse tubes were originally developed as an economical lowcapacity 11kV fuse for rural use.

While we no longer sell the fuse mounts (illustrated on the above), the glass fuse tube assemblies are stillreadily available to replace blown tubes.

We therefore maintain good stocks of the glass fuse tube assemblies.

Glass fuse tubesThe standard CEC rewire-able glass fuse tube has 24mm diameter end ferrules.

The tubes are manufactured from high pressure tubular gauge glass with fired fused ends. The endferrules are sealed to the glass tube ends with sulphur.

The end plugs unscrew to permit replacement of the blown fuse wire which is attached to a lead washerat each end.

The lead washer and attached fuse wire ends are then secured in place by screwing in the end plugs.

The product reference for the standard glass fuse tube assembly is:

94-00868-010.

The various parts of the 11kV glass fuse tube assembly are:1. Glass fuse tube-320mm centres,2. Glass fuse tube-292mm centres,3. Fuse end ferrule,4. Tin plated fuse end ferrule,5. Ferrule plug,6. Tin plated ferrule plug,

1/67

MV HRC DIN 45 fusesMedium voltage HRC DIN 45 fuses for use with the MV outdoor fusegearGeneral guide for MV HRC fuse applicationPlease refer to the fuse manufacturer’s data and recommendationswhen selecting fuses


1IntroductionShort-circuits produce considerable currents. These currents are related to the value of the installed powersource available and the network impedance between that power source and the point of the short circuitwhere the energy available is concentrated. The electro-dynamic and thermal effects that are produced bythe fault currents are capable of causing serious accidents, by heating or explosion.

HRC fuses are important protection devices due to their characteristic of short circuit current limitation.

The main characteristics of these HRC fuses are:c high current breaking capacity

c high current limitation effects

c low switching over-voltage

c low values of I2t.

c low power dissipation

c free of maintenance and aging

c for use in both indoor and outdoor installations

c provision of indicating or tripping striker

c low values of minimum cut-off current.

ApplicationsProtection of:c HV equipment (transformers, motors, capacitors, etc…)

c distribution networks in electrical utilities and industries.

c HV short circuits produced in the high voltage and low voltage circuits of transformers.

HRC fuses may be used in conjunction with switchgear.

DefinitionsRated voltage (Un) – service voltage, phase to phase, in kV, corresponding to the maximum voltage of the network in which the fuse may be installed. The following MV rated voltages have been defined:3.6, 7.2, 12, 17.5, 24, and 36kV.

Rated current (In) – value of the current that the fuse can withstand continuously without anomalousheating (usually 65°C on the contacts).

Rated cut-off current (I1) – value of the breaking capacity specified for a fuse corresponding to themaximum testing value of the fuse.

Ensure that the short-circuit current of the network at the point of application of the fuse is equal to, or less than, the value of I1 of the fuse used.

Switching voltage – corresponds to the maximum instantaneous value of voltage appearing across theterminals of the fuse, during its operation.

Virtual time – value of the Joule integral divided by the square of the value of the prospective current.

Current producing the maximum arcing power in the fuse (I2) – value, depending upon the fuserange, varying between 20 x In and 100 x In, for which breaking of all currents between I3 and I1 isguaranteed.

Minimum cut-off current (I3) – minimum value of the prospective current that causes the melting and thebreaking of the fuse current.

Note

for breaking, the current needs to be greater than that which is required for just the melting of the fuse.For current values below I3, the fuse melts but without the breaking function. In this case, the arcing willcontinue until an external device interrupts the current.Thus, the use of a fuse must be avoided for the range of currents between In and I3.

MV HRC DIN 45 fusesMedium voltage HRC DIN 45 fuses for use with the MV fusegearGeneral guide for MV HRC fuse applicationPlease refer to the fuse manufacturer’s data and recommendationswhen selecting fuses

1/68


1 Time / current characteristics – consist of curves representing the virtual time as a function of thesymmetrical components of the current (see figure 3, below, typical values shown only).

Cut-off current – maximum value of current attained during the breaking operation of a fuse.

Installation alternativesc in the open air,

c inside a switchboard,

c in an SF6 Ring Main Unit (RMU).

Current limitationThe HRC fuse limits the short circuit current to a value which depends on its rated current, on theprospective short-circuit current, and on the angle of the voltage wave at the moment of the fault.

In the diagram in figure 2, below, is shown the lines corresponding to each fuse, which determine themaximum current, peak value, that can be reached on a circuit protected by HRC fuses. The intersectionof those lines with the one straight I max-symmetrical or I max-asymmetrical indicates the prospectiveshort-circuit current, below which the fuses have not limiting capacity.

For example, the diagram indicates that if a short-circuit occurs in an unprotected installation whoseprospective short-circuit current is 5kA, the maximum current, peak value that will be produced, will be approximately 7kA = (5 x 2) kA in a symmetrical fault and 13kA = (5 x 2 x 1.8) kA in theasymmetrical case. These values have been determined tracing a horizontal line by the point ofintersection of the line corresponding to the prospective short-circuit current, in this case 5kA, with the straight lines I max-symmetrical and I max-asymmetrical.

If, in the same circuit, there was a 6A fuse, the current would be limited to 0.5kA peak value. A fuse of 16A would limit it to 1.5kA.

1/69

MV HRC DIN 45 fusesMedium voltage HRC DIN 45 fuses for use with the MV fusegearGeneral guide for MV HRC fuse applicationPlease refer to the fuse manufacturer’s data and recommendationswhen selecting fuses


1Fuse selection for transformer protectionWhen choosing the rated current of a fuse to protect a transformer, the following should be taken into account:

Transformer characteristicsc Rated power Pn (kVA)

c Short-circuit voltage Ucc (%)

c Rated current Int

c Inrush current 12 x Int (standard upper value)

c Short-circuit current Icc = (100 x Int) / Ucc

c Current during overload usual values

c Max. time withstand under short-circuit conditions on the transformersv Standard values:

2 seconds for transformers up to 630kVA,3 seconds for transformers between 631 and 3150kVA.

Fuse characteristicsc Rated voltage Un

c Rated current In

c Time / current characteristics according to curves

c Melting current (0.1s.) If (0.1 sec.)

c Melting current (2 or 3s.) If (2 sec.) or If (3 sec.)

c Minimum cut-off current I3

c Maximum cut-off current I1

c Fuse must withstand, without melting, the inrush current of the transformer, that is:Transformer rated currentInt < ( If (0.1 sec.) ) / 12

c Fuse must withstand the rated current Int and the possible overloads, usually 1.3 to 1.4 x Int of the transformer.

c If the installation and working conditions are not well known, the fuse rated current chosen will be theone immediately above 1.5 x Int.

c To break the short-circuit current of the installation, that is I1 > Icc.

c To break the short-circuit current of the transformer Icc (fault in the secondary terminals), that is Icc >= I3.

c a transformer protection fuse must be chosen so as to avoid melt damage in service before a fault.This, so that for the short-circuit current Icc predicted for the transformer, the fuse will blow.v For transformers up to 630kVA: If (2 sec.) <= Icc.v For transformers from 631 to 3150kVA: If (3 sec.) <= Icc.

c The fuse’s rated voltage to be greater or equal to the line voltage.

Please refer to the manufacturer’s data and recommendations when choosing fuses.

Fuses vs circuit breakersThe following article is reprinted from a Schneider Medium VoltageNews and discusses the relative merits of HRC fuses and circuitbreakers for protection and discrimination of circuits

1/70


1 MANY PEOPLE like to install 11kV fuse-switches for protection. Allied with a load-break switch, they formcheap and reliable protection against a major fault. Fuses have the advantages of fast operation andlimiting the amount of current let through to down-stream circuits. On the other hand, circuit breakers canbe reset easily after operation, and the time of operation delayed, so that discrimination with otherprotection is possible. For these reasons, there is a steady movement towards circuit breaker technology.

Medium voltage fuses have one other drawback which is often not well understood by those who seekcheap protection: their inability to handle overloads, which can result in catastrophic failure.

11kV indoor fuses are generally made from a thin silver element wound helically around a ceramic former.This is encased in a glass-resin sheath which is filled with quartzite (fine sand). The end caps are made of metal, and a tungsten wire stretching along the centre of the ceramic former holds back aspring loaded striker pin mounted in the top cap. The method of operation is that when the minimumbreaking current passes through the element, the element melts and the current commutes to thetungsten wire. Being of high resistance, this also melts quickly, releasing the striker pin which hits a triggerbar and operates the load-break switch. The characteristics of the fuse are determined by notching thesilver element.

Medium voltage fuses are divided into two types: “full range”, or “back-up”. Full range fuses operate likelow voltage fuses: they have a rated current and, when the current passing through the fuse elementexceeds this value, the element melts. However the vast majority of medium voltage fuses supplied areback-up fuses, for which the rated current In is not the same as the minimum breaking current I3. TypicallyI3 is three times In, but varies according to the manufacturer. The point is that currents between In and I3cause the fuse element to melt, but only in spots. The full voltage of 11kV is then impressed across thesesmall gaps and micro-arcing takes place which is known as “candling” of the fuse. The current continuesto flow but unstable voltages are formed in the circuit, and arcing within the fuse can cause the fuse topuncture or explode. The top caps of medium voltage fuses have edges (some rounded, sometimessharp) which form a launching place for arcs external to the fuse. In addition, the overloading can heat thefuse and the fuse-holder, causing expansion and the creation of gaps between the holder and the fuse.Micro-arcing can occur in these gaps, leading to ionisation of the air and further major arcing.

Where a fuse has a glass reinforced resin sheath, the heat generated by the arcing can cause the resin toburn, releasing large quantities of fine soot.

It is obvious, therefore, why the operating region between In and I3 is known as the “forbidden region”! It is essential not to overload a medium voltage back-up fuse. For many installations, this is not a problem.The loads are well known and steady, and the correct fuse can be selected and used safely.It is generally recognised that if loads are added to the fuse-protected circuit, then the fuse rating needsto be re-evaluated.

What can be overlooked, though, are the effects of harmonics, which may not have been quantified, or theeffects of an undetected high resistance fault. Both of these can and have resulted in fuse failures due tooverloading.

Where a doubtful situation exists, there are some measures which can be taken.

c Merlin Gerin “Fusarc” fuses have a fibreglass sheath coloured green. As the fuse heats up throughoverloading, the varnish on the sheath oxidises, turning brown. This is a sure indication of overloading.

c A current transformer can be placed in the circuit and used to operate the load-break switch at overloadcurrents. Although technically the switch is only rated for load currents, in this situation it will be calledupon to break a higher current and this is recognised in IEC 420, which requires the switch to break 7In three times.

In Summary

Back-up fuses

These fuses are able to break all currents from rated breaking current down to the minimum breakingcurrent (I3). Currents below their minimum breaking current ranging between In and I3 cannot beinterrupted by back-up fuses.

General purpose fuses

These fuses are able to break all currents from rated breaking current down to the currents which causemelting of the fuse in 1 hour.

1/71

HM-LA motor operatorMotorised operators for 11kV, 22kV, 33kV and 66kV disconnectors:Some times known as a motor driven handle, hence the type code: HM.Designed and manufactured in New Zealand by Canterbury Engineeringfor the local or remote operation of CEC disconnectors. When connectedup to an existing disconnector, the HM-LA replaces the disconnector’sexisting manual handle.SECTION 1


1Description of the HM-LA motor operatorThe HM-LA (or Handle, Motor operated) is designed to enable CEC disconnectors, from 11kV up to 66kV,to be locally or remotely electrically operated.

The HM-LA includes an actuator powered by a 24Vdc motor (48Vdc, 110Vdc motor voltages available).

The design of the mechanism and controls is deliberately simple to avoid maintenance and operatingproblems that can occur with more complicated equipment in rural and remote environments.

The HM-LA controls do not contain any electronics for similar reasons.

However, many of our customers fit their own compact RTUs, communication and battery gear inside ourHM-LA’s stainless steel weather proof cabinet with considerable success. There is limited space on theright hand side, and at the bottom of, the cabinet for the customer’s gear if this latter is sufficientlycompact.

CabinetsThe standard stainless steel cabinet is 500mm wide, 700mm high, and 250mm deep (including door).

We can supply a second empty cabinet for mounting RTU and communications gear separate from theHM-L’s own cabinet.

Alternatively we have special cabinets with additional space provided for the housing of customerequipment, including either:

A) additional height with space at the bottom of the cabinet, or

B) A separate top compartment with divider between the HM-LA space and the customer’s space, or

C) Additional depth for mounting equipment on a door gear tray.

HM-LA controlsThe control circuit accepts fleeting ‘open’ and ‘close’ signals from the customer’s RTU or other remotecontrol system.

Auxiliary contacts on the selector switch (remote position indication) and limit switches (OPEN orCLOSED position indication) are provided for remote monitoring of the HM-LA’s status.

The customer’s remote controls and indications are wired to terminal blocks on the same DIN rail as theinternal connection terminal blocks.

The separate 24Vdc supplies for the motor circuit and control circuit are provided with their own fuses onboth the positive and negative legs.

A remote-OFF-local selector switch allows either local electrical control using the pushbuttons on thecontrol panel inside the cabinet, or remote control using the customer’s remote control cabling, or OFFcontrol that isolates all control signals to the contactors that initiate and hold on the power to theactuator’s motor.

In addition, a manual over-ride handle is provided which allows operation of the disconnector in the eventof loss of power supply and for setting up (please refer to page 1/74 for the manual operating procedure).An internal pin is easily removed to mechanically disable the power operation when the manual handle is used.

Anti-condensation heaterThere is a 230 Volt 40 Watt anti-condensation heater with thermostat and isolator in the cabinet as standard.

HM-LA motor operatorMotorised operators for 11kV, 22kV, 33kV and 66kV disconnectorsDescription continued…

1/72


1 Cabinet mountingThe operating mechanism and bearing/output shaft are mounted on a 10mm thick galvanised steel plateinside the cabinet. Galvanised steel mounting channels are fitted to the rear of the cabinet to allow theHM-LA cabinet to be mounted to the pole. These are attached to the internal chassis so that the operatingforces are carried directly to the pole and not by the cabinet shell.

Power supplyOur standard model is designed for 24 Volt dc supply from the customer’s system.

Other voltages may be catered for on request.

The motor actuator circuit and the control circuit are separated and arranged to have their own supplies via their own HRC fuses to both the positive and negative lines to the equipment. Effectively, wecan provide HM-LA’s with different voltages for the motor actuator and control circuit if so required.

Please refer to the schematic on the opposite page for typical details for 24V dc supplies.

The actuator has no dc standing current drain on the batteries while inactive.

The DC power supply and / or batteries are the customer’s supply.

Compatibility with disconnectorsThe HM-LA may be used with the following range of switchgear:

Actuator rating 2224 Newtons

Disconnectors

IRW-955 11kV Rocking post

IRW-DA2 11kV Rocking post



IRW-NL7 33kV Rocking post

IRW-NG10 33kV Rocking post

IRW-AF 33kV Centre rotating

Earth switches

EIR 33kV

Actuator rating 4448 Newtons

Disconnectors

IRW-NL7 33kV Rocking post – vertically mounted

IRW-NG10 33kV Rocking post – vertically mounted

IRW-NN10 33kV Rocking post

IDW-AF 66kV Centre rotating

EIR 66kV Earth switch

1/73

HM-LA motor operatorMotorised operators for 11kV, 22kV, 33kV and 66kV disconnectors

Motor actuator and control circuit electrical schematic


1

Notes

1. The condition shown is with the selector switch in the OFF position.2. The limit switches are shown with the disconnector open, with the actuator retracted.

Limit switch positions in this condition are:–LS1 and LS3 are in their normal condition (off the cam).LS2 and LS4 are depressed by the cam.

3. Components shown are for 24V DC power and control.Other voltages available.

4. Bond control cabinet to earth terminal.

The schematic and notes are extracted from drg 4587.

HM-LA motor operatorMotorised operators for 11kV, 22kV, 33kV and 66kV disconnectorsManual operating procedure

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1 WarningThese instructions should be used in conjunction with any applicable company procedures and safetyrules for operating air break switches.

Use of manual handleThe HM-LA’s mechanism is designed so that the disconnector may be easily manually operated both forsetting up and in case of emergency.

Manual operation1. Turn control panel selector switch to OFF (centre position). This prevents the unit from being

operated remotely.

2. Remove retaining clip A and withdraw drive pin B.

3. Pull actuator piston forward out of yoke. The cylinder will be held by the restraint.

4. The manual handle C is stored on the left side of the cabinet. Remove it from the clips (see figure 3).

5. Insert handle in tube as shown in figure 2 retain it with the split pin.

The disconnector may now be operated as a manual switch.

Automatic operationTo revert to automatic operation reverse the above procedure. Ensure that when finished that the controlselector is returned to the REMOTE position.

Local operationThe LOCAL position of the control selector permits local electrical control using the push buttons. Ensurethe control selector is returned to the REMOTE position when finished local operations.

PadlockingThe switch can be padlocked in either the open or closed position using the padlock facility on the mainshaft. Ensure the control selector is turned to OFF while padlocked.

Figure 2

Figure 1

Figure 3

1/75

LB – Load break interruptersSelection and application of load break interrupters


1IntroductionFormal definitions of a disconnector limit any switching performance to opening and closing a circuit when either negligible current is made or broken or when no significant change in voltage across theterminals occurs, i.e. Definitions in IEC 60694:

“DisconnectorMechanical switching device which provides, in the open position, an isolating distance in accordance withspecific requirements.

Note A disconnector is capable of opening and closing a circuit when either negligible current is broken ormade, or when no significant change in the voltage across the terminals of each of the poles of thedisconnector occurs. It is also capable of carrying currents under normal circuit conditions and carryingcurrents for a specific time under abnormal conditions such as those of short circuit”.

“Isolating distance (of the pole of a mechanical switching device):

The clearance between open contact meeting the safety requirements specified for disconnectors”.

Disconnectors however are generally understood to have some making and breaking performance.

In selecting disconnectors it is necessary to review the switching performance required for the particularapplication. What will the disconnector be expected to safely achieve as regards opening and closing theelectrical current path.

The choices vary from a simple isolator to disconnectors incorporating various degrees of interruptioncapacity.

Selection of interrupting attachments for disconnectors

1. Wiping arc hornsThe wiping arc horn is the simplest form of interrupting attachment and arc extinction is achieved bysimply stretching out the arc, until the critical arc length is reached, when the arc is extinguished and the current flow interrupted.

Phase spacing, earth clearances, maximum possible arc reach of the current to be broken and windconditions must all be carefully considered when using wiping arc horns for load switching.

Therefore this method of current breaking should be confined to:

(a) Charging currents of substation busbars or very short transmission lines.

(b) Small magnitudes of transformer magnetising currents.

(c) Limited levels of load current at normal power factors.

(Please refer to the section on “Load breaking using arc horns” on the next page).

2. Flicker or whip arc interruptersThe flicker arc horn consists of a spring loaded rod arranged with a latching hook such that it is subjectedto large deflections when the switch is opened.

In the opening operation, when a substantial air gap has been established between the main disconnectorcontacts, the flicker horn is released from the hook and its high speed of operation assists to “whip” outthe arc.

However, due to the “exposed arc” nature of the load breaking the application of these units should belimited to interrupting line charging currents or transformer magnetising currents.

Whip interrupters are a more sophisticated flicker and although working on the same principle control theflick action and establish a somewhat larger air gap with correspondingly improved performance.

(Please refer to the section on “Load breaking using arc horns”, below).

LB – load break interruptersSelection and application of load break interrupters

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1 3. CEbreak load-break interruptersCanterbury Engineering’s 11kV load break interrupter for converting a standard disconnector into a 400Aload break switch.

Details of the CEbreak are found on page 1/78.

4. Ezibreak Load-break InterruptersConverts disconnectors to load break switches. The Ezibreak may be used with 11kV, 22kV and 33kV disconnectors.

Details of the Ezibreak are found on page 1/79.

Load breaking using arc hornsGuaranteed performance data covering the interrupting capacity of arc horns cannot be given because ofthe numerous factors that influence the successful interruption of power arcs.

Each particular case should be analysed on its own merits, evaluating:

(a) Current and voltage.

(b) Atmospheric conditions: i.e. prevailing wind and weather.

(c) Installation conditions – phase spacing and surrounding equipment.

The following details are a summary of the findings of various overseas tests and papers on the subjectand are given as a guide to aid the personal evaluation of suitable limits by a qualified individual.

1. An arc formed on adequately separated electrodes will go out if it is free to expand to its critical length.

2. A disconnector will successfully interrupt a current if dimensions are sufficient to permit the arc to growto its critical length. However, wind blowing in line with the arc horns may help to sustain the arc, and isa question for review at the time of proposed switching application.

3. Horizontal break switchgear should not be required to interrupt any current without the aid of suitableinterrupter devices.

4. Arc reach for currents below 100 Amps depends upon both voltage and current. The maximum reachfor practical use in this range is:

0.005 metres per Amp per kV across the open gap.

5. The arc reach for currents from 100 to 300 Amps is proportional to voltage but independent of currentmagnitude. The maximum reach for practical use is:

0.50 metres per kV across the gap.

[The arc reach of currents above 300 Amps is considered as being only of academic interest.]

‘Arc reach’ is “defined” as the distance from a point midway between the arc extremities to the mostremote point of the arc at the time of its maximum length.

1/77

LB – load break interruptersSelection and application of load break interrupters


1The upper allowable limit for the arc reach determines the value of the maximum load that can be safelyopened by an air break sectionising switch.

A review of the references quoted below suggests that 50% of the phase/phase spacing of the switch beused, however consideration must also be given to phase earth clearances to ensure conservativebreaking.

For vertical break switches, and applying the 50% limit, the formula in the box below can be used forcalculating maximum currents that can be broken by vertical break of rocking post disconnectors.

Noteif the value of current obtained from expression (a) exceeds 100A then use expression (b).

Interrupted at line voltage

References

1. “Interrupting Ability of Horn Gap Switches” by Andres, James & Anderson, AIEE Transactions 1950, Vol.69.

2. “A Study of Transmission Line Power Arcs” by Paul Ackerman, Engineering Journal, May 1928, Vol. II.

3. “Switchgear Installation”, Kireyev & Kovarsky.

4. “Outdoor H.V. Switchgear”, Todd & Thompson.

5. B.S. 5253-1975.

6. AS.1025-1971 and AS.1306-1977.

7. ANSI C37-34 1970 and C37-30 1970.

LB-C24 – CEbreak load break interrupterThe CEbreak interrupter load break head may be simply fitted to CanterburyEngineering 11kV disconnectors to convert off-load disconnectors into reliable loadbreak switches capable of switching load currents up to 400AAn economic, New Zealand designed and manufactured, enclosed arc, load break deviceProvides reliable, life long load break performance, under all New Zealand climaticconditions

1/78


1 General descriptionThe addition of CEbreak load break heads to a standard 11kV disconnector converts the switch from an off load isolator to a reliable load break switch capable of switching load currents up to 400 Amps.

The interrupter carries no load current with the switch in the ‘closed’ position. During a load switchingoperation load current is transferred to the interrupter immediately prior to the opening of the main switch contacts.

The load current is then interrupted by the high speed separation of the contacts in the interrupter arcing chamber.

The resulting arc is effectively extinguished with the gases produced in the chamber.

ApplicationReadily fitted to IRW-DA27 and IRW-DA87 Canterbury Engineering rocking post disconnectors.

With suitable mounting brackets it may be adapted to other switch types.

RatingsBased on extensive HV laboratory tests and operational field trials, the assigned ratings are:

Service or system voltage 11kV

Active load breaking 400A

5% active load breaking 20A

Loop current 400A

0.15 pf capacitive 20A

FunctionThe interrupter has a tubular arcing chamber incorporating both a liner and moving shaft which produce arc suppressing gases. The arc and the resulting gases are compressed at high pressure into the annular area between the liner and the shaft. The arc is extinguished because the dielectricstrength of the non-carbonising gas builds up at a greater rate than the rise of the recovery voltagebreakdown strength.

1/79

LB – Ezibreak load break interrupterThe Ezibreak interrupter load break head may be simply fitted toCanterbury Engineering disconnectors, from 11kV up to 33kV, toconvert off-load disconnectors into load break switches capable ofswitching transformer full load currents up to 630A at 11kV and 22kV,and 200A at 33kV.


1General descriptionThe ‘Ezibreak’ interrupter has been designed to provide reliable load break operations and is for use inconjunction with air break disconnectors assigned to general purpose switching operations.

ConstructionThe ‘Ezibreak’ body is a moulded material which has been carefully selected for strength as well asresistance to prolonged UV exposure.

The operating mechanism is factory adjusted and enclosed in sealed compartment to prevent ingress ofmoisture and consequent deterioration of moving parts. All bearings are self lubricated to avoid thenecessity of maintenance during the service life of the interrupter.

The ‘Ezibreak’ arcing chamber features a liner which produces arc extinguishing gases during on-loadswitching operations. Load breaking contacts are manufactured from a silver tungsten alloy which resistexcessive erosion under arcing conditions. Emissions of exhaust gases through the exhaust port areminimal even under full load switching operations.

OperationWhen mounted on an airbreak switch disconnector, the interrupter carries no load current when the switchis in the ‘closed’ position. During a load breaking operation, load current is transferred to the interrupterimmediately prior to the separation of the switch main contacts. The load current is then interrupted by the high speed separation of the contacts in the interrupter arcing chamber.

When the switch disconnector reaches the fully open position, the operating arm of the interrupterautomatically returns to the reset position, and is ready for the next operation.

Field application

Breaking contacts

Service Transformer Transformer Linevoltage off load full load charging

P.F. < 0.15 (Max) P.F. < 0.15

12kV 25A 630A 25A

24kV 20A 630A 20A

36kV 15A 200A 15A

LB-Z5 – summary of arc horn typesThe following description is based on the CEC document “Technical Description LB-Z5”, 30 Nov. 1999:“Subject: Arcing horn types and performance benefits”

1/80


1 “Subject: arcing horn types and performance benefits”

1. Interrupting attachmentsInterrupting attachments, ranging from wiping arcing horns to confined arc loadbreak heads, aredescribed in the preceding pages (the ‘LB’ part) of this MV Catalogue.

2. Wiping arc hornsWiping arc horns have a long history and were invariably fitted to disconnectors from 11kV upwards longbefore flicker arc horns were introduced. Their objective was and still remains, to draw any induced arcingaway from the main switch contacts. Whether or not they actually manage to achieve that objectivedepends very much on a complex combination of factors, i.e.:

System load breaking type and its magnitude.

Climatic conditions at the time, particularly wind and its direction.

Disconnector design, e.g. vertical opening movement or side break.

Disconnector opening speed, e.g. geared operation or manual .

For some designs, wiping arc horns perform the addition function of contact closing guide (e.g. as with theturn over brackets on our 66 to 220kV IDB/J centre rotating type disconnectors).

3. Flicker arc hornsFlicker arc horns are now generally fitted to all of our 11kV to 33kV line disconnectors. Their substantialbenefits over wiping arc horns include:

The breaking point is positively moved away from the main contacts.

Breaking is delayed and then completed quickly within the same plane thusminimising the potential for wind distortion.

The ‘quick’ operation is independent of disconnector opening speed.

Flicker arc horns therefore increase the probability of breaking residual or induced system loads, with far less dependence on the weather conditions at the time.

4. Critical arc length, however, is still critical!

Neither flicker arc horns, and nor especially wiping arc horns, are able to enhance the load breakingability of a disconnector where it’s basic dimensions do not allow the arc to expand fully to its critical length.

5. In summary, our disconnectors are usually equipped as follows:–

11 to 33kV line disconnectors, e.g. IRW/DA2 to IRW/NL7 Flicker arc horns.Fitted regardless of application.

33kV ‘substation’ disconnectors, e.g. IRW/NG10 Flicker arc horns if line mounted.No arc horns if substation installation.

33 to 66kV centre rotating disc, e.g. IDW/AF Same as NG10 above, i.e.Flicker arc horns if line mounted (both ends) No arc horns if substation installation.

Substation switches may, of course, have arc horns fitted if the system requirements would be assisted by their presence.

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P Series – isolating links11kV, 22kV and 33kV isolating links


1IntroductionThe P Series of isolating links includes 11kV, 22kV, and 33kV ranges for both ‘flat face’ and cross-arm mounting.

They may be used in outdoor or indoor applications.

The eye for pull rod also releases the safety catch that keeps the blade closed during operation.

ConstructionBase – flat faced mounting: hot dipped galvanised mild steel lipped channel.

Base – cross-arm mounting: cast aluminium.

Current carrying parts: cast gunmetal, HDHC copper.

Fixed contacts (2): both contacts, at each end of link, are high pressure line contacts.

Moving contacts: copper blade.

InsulatorsChosen to suit system voltage and application. Please specify environment when ordering.

TerminalsTerminal pads and bolt hole sizes are chosen to suit the current rating of the link.

The single bolt terminal pad is 40mm x 40mm with 11mm dia. hole; the double bolt terminal pad is 40mm x 80mm with 14mm dia. holes with 45mm hole centres.

The P Series includes the following models of isolating link:

The short time current rating for all these isolating links is 21kA for 1s.

Link type Continuous Mounting Terminal pads Product ref.rating type

11kV isolating links

PL-E40 400A Flat face 1 bolt, 11mm dia. 00-PL-E40

PL-E50 500A Flat face 2 bolts, 14mm dia. 00-PL-E50

PL-H40 400A Cross-arm 1 bolt, 11mm dia. 00-PL-H40

PL-H50 500A Cross-arm 2 bolts, 14mm dia. 00-PL-H50


PL-F50 500A Flat face 2 bolts, 14mm dia. 00-PL-F50

PL-F60 630A Flat face 2 bolts, 14mm dia. 00-PL-F60


PL-J40 400A Flat face 1 bolt, 11mm dia. 00-PL-J40

PL-J60 630A Flat face 2 bolts, 14mm dia. 00-PL-J60

PL-K40 400A Cross-arm 1 bolt, 11mm dia. 00-PL-K40

PL-K60 630A Cross-arm 2 bolts, 14mm dia. 00-PL-K60


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1 Series PL-E__ – 11kV isolating link, flat face1. Optional fixed clamps supplied on request.

2. Insulator 95kV Impulse withstand, 298mm creepage.

3. All current carrying components copper or copper alloy. Contacts are high pressure line contact – NOTsilver button.

4. Large diameter pull stick eye.

Product ref. – 00-PL-E__

Drawing – 3577-__

1/83



1Series PL-H__ – 11kV isolating link, cross-arm1. Single bolt mounting M16 through cast aluminium base.

2. Insulator 95kV Impulse withstand, 298mm creepage.

3. Terminal pad dimensions same as PL-E.



6. P5000 bronze earth spigot – fit to either side.

Product ref. – 00-PL-H__

Drawing – 3578-__


1/84


1 Series PL-F__ – 22kV isolating link, flat face mounting1. Optional sliding clamp can be provided to adjust the mounting centres up to 365mm max.

2. Insulator IN-D4130 – 125kV Impulse withstand, 480mm creepage.


For 630A rating, link has silver plated contacts and all components tin plated in the current path.


Product ref. – 00-PL-F__

Drawing – 3662-__

1/85



1Series PL-J__ – 33kV isolating link, flat face mounting2. Insulator IN-D3464 – 200kV Impulse withstand, 673mm creepage.


For 630A rating, link has silver plated contacts and all components tin plated in the current path.


For cross-arm mounting, see PL-K, details on following page.

Product ref. – 00-PL-J__

Drawing – 3613-__


1/86


1 Series PL-K__ – 33kV isolating link, cross-arm mountingMounting brackets on base shown in the illustration, below:

All other details as per PL-J__ flat base option, detailed on the previous page.

Product ref. – 00-PL-K__

Drawing – 3651-__

1/87

H – accessories for disconnectorsAccessories for Canterbury Engineering disconnectors, continued...Auxiliary switches,Pipe guides and insulating links for operating pipes,Operating handles,Operating accessories


1HA – auxiliary switches

HA-AG – linear auxiliary switchesSuitable for use with Series HV vertical pump type operating handles and applications where indication ofvertical movement is required.Twin cable entry (15mm dia.) intended for use with jubilee clip as armour clamp with Denso tape bindingin lieu of proprietary cable gland.Terminal stud diameter is M5.Rated 230V 10A at 50Hz and 230V 1A at dc.


HA-AG11 4-way standard 2 n/o and 2 n/c contacts 00-02389-011

HA-AG21 6-way 3 n/o and 3 n/c contacts 00-02389-021

HA-AF11 – auxiliary switch kitFor use with HV-B (11kV) operating handles only.Uses Series HA-AG11, 4 way auxiliary switch, with 2 n/o and 2 n/c contacts.Includes all mounting hardware.


HA-AF11 Auxiliary switch kit 4 way auxiliary switch, with 2 00-02785-025n/o and 2 n/c contacts

HA-AJF11 – rotary auxiliary switchModel Description Reference Code

HA-AJ11 4-way Rotary auxiliary switch 00-02432-011

HA-AJ21 6-way Rotary auxiliary switch 00-02432-021

HA-AJF11 – Reyrolle auxiliary switch (refer to drg SA 2575)Model Description Reference Code

HA-A various-way Reyrolle auxiliary switches 91-02575-x-yyE.g. 8-way Auxiliary switch 91-02575-8-45

Please contact us for details of the options for auxiliary switches.


1/88


1 HA-AT-D – rotary auxiliary switch unit, singleModel Description Reference Code

HA-AT-20 D Less Reyrolle Single cab. assy s/s 00-03329-020auxiliary switch sealed type

HA-AR-D – rotary auxiliary switch unit, doubleModel Description Reference Code

HA-AR-20 D Less Reyrolle Double cab. assy s/s 00-03329-020auxiliary switch sealed type

Torsional operating handle Series HR-B, complete with Series HA-A( )D rotary auxiliary switch.

The illustration below is extracted from drawing 4430.

It shows a standard HR-B rotary operating handle complete with Series HA-A( ) rotary auxiliary switch.

The Type 10 (as shown) – Series HA-AT auxiliary switch contains a single Reyrolle switch unit from 4 upto 12 ways, ref. drg MA3329-10.

The Type 20-Series HA-AR auxiliary switch contains a double Reyrolle switch each from 4 up to 12 ways,ref. drg MA2797-20.

For assembly details of auxiliary switch and cabinet, ref. drg MA 3329-10. Special features are as shownon this drawing.

The rotary auxiliary switches are: HA-AT-D (label ‘3’), and HA-AR, (label ‘4’ on immediate left).

3 or 4

1/89



1HA-AU( )D – single auxiliary switch unit, with stainless steelcabinet and door(Refer drg 3336), for HV-G handles


HA-AU( )D Auxiliary switch 00-03978

HA-AU10 D double Auxiliary switch 00-03979

HA-AU( )D: double auxiliary switch unit, with stainless steelcabinet and door(Refer drg 3336), for HV-G handles


HA-AV( )D Auxiliary switch 00-03978

HA-AV10 D double Auxiliary switch 00-03979

Pump handle Series HV/G fitted with an auxiliary switch stainless steel cabinet, Series HA-AU ( ) D.

The illustration below has been extracted from drawing 3978.

It shows a Series HA-AU ( ) D stainless steel cabinet.

A Reyrolle auxiliary switch is also shown enclosed in the cabinet and fitted with a 20 tooth gear meshingwith a 10 tooth pinion that is attached to the handle arm.

The Reyrolle switch may be 4, 8 or 10 way.


1/90


1 HF – insulating linksFor insulating operating pipes


HF-120F 20NB, GRP, drg 4148 sh20 00-HF-120F

HF-125F 25NB, GRP, drg 4148 sh25 00-HF-125F

11kV insulating link assembly including fibreglass rod, Series HF-1( ).

HG – pipe guides

HG-L pipe guidesModel Description Reference Code

HG-L40 20NB, for wooden poles 00-HF-120F

HG-L60 20NB, for concrete poles 00-HF-125F

HG-PB pipe guidesFor 11kV to 33kV IRW-DA disconnectors (drg MA 1518)


HG-PB50 15-20NB, standard 00-HG-PB50

HG-PB55 15-20NB, with stainless steel fasteners 00-HG-PB55

HG-PB60 25NB, standard 00-HG-PB60

HG-PB65 25NB, with stainless steel fasteners 00-HG-PB65

1/91



1HG – PC pipe guidesFor 33kV to 110kV disconnectors (drg MA2029)


HG-PC50 25NB, standard without universal, R197 00-HG-PC50

HG-PC60 25NB, without universal, R279 00-02029-060

HG-PC60 25NB, without universal, R279 00-02029-060

HG-PC20 25NB, complete with universal, R197 00-02029-020

HG-PD pipe guidesFor 11kV to 33kV disconnectors (drg MA 4123)


HG-PD20F 20NB, with fibreglass insulating link 00-HG-PD20F

HG-PD25F 25NB, with fibreglass insulating link 00-HG-PD25F

Holding down centres for pipe guide in polemounted position are dia. 14mm x 76mm or inthe angle mounted position are dia. 14 x 44mm.

Also available with universal to allow movementin two different planes.

Note It is recommended that the distancebetween operating handle and pipe guide orswitch axle and pipe guide be less than threemetres (3000mm).


1/92


1 HG-PE eyebolt type pipe guideAlternative to HG-PB50 hinged pipe guide for 11kV disconnectors (drg 4570)


HG-PE12/380 Galvanised eyebolt, with 38mm dia. eye 00-HG-PE12/380Requires a 14mm dia. Hole through wooden or concrete poleShank has M12 thread, supplied with two M12 galv. nut and two square M12 x 50 x 50 x 3 galv.Washers

HJ-C mechanical interlock system for 110kV handles

HJ-C mechanical bar interlock system – Ref. drg 2226The HJ-C3 mechanical interlock system provides an interlock between two 110kV switch operatinghandles – that is, between an HV-G610 earthing switch handle and an HV-G910 disconnector switch.

Normally used with HA-AU-D auxiliary switch boxes – a standard box and a left hand box.

Reyrolle auxiliary switches may be fitted into the boxes.

With the addition of a locking plate, the Handles become:

HV-G940 Var and HV-G640 Var (LH).

Please contact us with your requirements and we shall prepare a detailed offer for your particular application.

1/93



1HS-A counter balance spring assembliesUsed to balance operating forces when a 33kV Series IRW disconnector is mounted in the vertical position


HS-A10 Counter balance spring assembly: for 25NB pipe 94-02804ref. P1201 and SA1022, pipe guide mounted

HS-A15 Counter balance spring assembly: for 20NB pipe 00-03562ref. P1201 and SA1052-22, pipe guide mounted

HS-A25 Counter balance spring assembly: for 25NB pipe 94-02866-025ref. P1198 and SA1052-10, channel mounted

Standard – pipe guide mounted,Series HS-A10

Used to balance operating forces when a 33kVSeries IRW disconnector is mounted in thevertical position.

Used in conjunction with Series HG-PC pipeguide where one end of balance spring isattached to the pipe guide hinge pin and theother end is clamped to the 25NB galvanisedoperating pipe.

All ferrous parts hot dip galvanised.

Spring epoxy coated (grey).

Alternative – channel mounted, Series HS-A25

Similar to Series HS-A10.

For use when one end of balance spring is mounteddirect to the switch bearer channel and the otherend is clamped to 32NB galvanised operating pipewhere no pipe guide is used.

To increase the stability of the operating pipe over alonger length, allow for the side force from thespring, a 32NB operating pipe is necessary.

A pipe reduction socket and short length of 25NBpipe is required at each end to allow the 32NB pipeto be fitted to the standard 25NB fittings.


1/94


1 HS-L trip mechanismsolenoid operated trip linkagemechanism, ref. drg 3908, sheet 1 and 2. Used with fault throwers, Series ER-L (33kV) and ER-M (66kV and 110kV).

Solenoid operated trip mechanism Series HS-L

The illustration on the left is extractedfrom drawing 3908.

The illustration left shows the HS-Lfitted to an ER-L fault thrower

Items 1 to 5 are the HS-L tripmechanism with control voltages 12V,24V, 50V, 110V, and 125Vdc,respectively.

Please contact us with yourrequirements and we shall prepare a detailed offer for your particularapplication.

1/95



1Operating handlesThe following pages feature operating handles and accessories for mounting operating handles to poles.

Universal operating handle mounting strap‘One size fits all’ universal mounting strap for mounting 11kV and 33kV disconnector operating handles toconcrete poles with recessed faces.c four straps required to mount one operating handle.


5555-6 Universal operating handle mounting strap 95-05555


1/96


1 Mounts, for operating handlesThese operating handle mounts consist of components fabricated from mild steel channel and flat that arehot dip galvanised after all cutting and drilling; and from galvanised stud; and supplied complete withgalvanised nuts, flat washers and spring washers.


Type 11 1 side, 1 handle: 2 short mounting channels and 2 P4981-xxxshort clamping flats, plus studs, nuts, and P3507-xxxwashers to suit P4983-yyy

Type 22 2 sides, 2 handles: 4 short mounting channels, P4981-xxxplus studs, nuts and washers to suit P4983-yyy

Type 12 1 side, 2 handles: 2 long mounting channels and P4982-zzz2 short clamping flats, plus studs, nuts, and P3507-xxxwashers to suit P4983-yyy

Type 23 2 sides, 3 handles: 2 long mounting channels and P4982-zzz2 short mounting channels, plus studs, nuts, P4981-xxxand washers to suit P4983-yyy

Type 24 2 sides, 4 handles: 4 long mounting channels, P4982-zzzplus studs, nuts and washers to suit P4983-yyy

1/97



1HR-1009, old style, rotary operating handleRotary handle complete with auxiliary switch link.Used with 66kV to 110kV switches.May be used with a HA-AJ11 rotary auxiliary switch.


HR-1009 Rotary handle, complete with auxiliary switch link 00-01009-060

HR-B rotary operating handleRotary handle complete with auxiliary switch link.Used with 66kV to 220kV switches.May be used with rotary auxiliary switch.


HR-B Rotary handle, complete without auxiliary switch link 00-02435-020

HR-B Rotary handle, complete with auxiliary switch link 00-02435-010

HR-E rotary operating handleRotary handle complete with auxiliary switch link.Used with 33kV to 110kV switches.May be used with rotary auxiliary switch.Provision for two deadlocks.


HR-E20 Rotary handle, standard to drg 3999 00-02435-020

HR-E10 Rotary handle, 90 degree rotation 00-02435-010

HR-M rotary manual driveUsed with 66kV to 220kV switches.


HR-M10 6 T.P.I. (turns per inch), double start (DS) 00-03252-010

HR-M20 6 T.P.I. (turns per inch) 00-03252-020

HR-M30 13 T.P.I. (turns per inch) 00-03252-030

HR-M50 6 T.P.I. (turns per inch), double start (DS) 00-03252-050

HR-M70 2.0mm pitch 00-03252-030

For all the above items, please contact us for more details.


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1 HV-B operating handlePump style handles. Used with 11kV switches.


HV-B10 20NB, drg 1656-10 00-HV-B10

HV-B10E 20NB, for earthing 00-HV-B10E

HV-B15 20NB, complete with all stainless steel fasteners 00-HV-B15

HV-B20 20NB, spade grip 00-HV-B20

HV-B30 25NB 00-HV-B30

HV-B35 25NB, complete with all stainless steel fasteners 00-HV-B35

HV-BR10 20NB, with reverse handle. Drg 3183:10 00-HV-BR10

HV-BR30 25NB, with reverse handle. Drg 3183:10 00-HV-BR30

HV-BU40 20NB, for wood pole. Drg 4213:40 00-HV-BU40

HV-BU42E 25NB, for wood pole. Drg 4213:40, + earth strap 00-HV-BU42E

HV-BU60 20NB, for concrete pole. Drg 4213:40 00-HV-BU60

HV-BU62E 25NB, for concrete pole. Drg 4213:60, + earth strap 00-HV-BU62E

HV-G operating handlesUsed with 11kV switches.


HV-G910 25NB, complete with HA-AV ( ) D 00-HV-G910

HV-G930 25NB, complete with HA-AV ( ) D, and 00-HV-G930catch release

HV-D operating handlesUsed with 33kV to 110kV switches. Ref. drawing MZ 1092 sheet 1.


HV-D610 25NB 00-HV-D610

HV-D615 25NB, complete with stainless steel fasteners 00-HV-D615

HV-D630 25NB, complete with release catch 00-HV-D630

HV-D640 25NB, complete with interlock fittings 00-HV-D640

HV-D910 25NB 00-HV-D910

HV-D930 25NB, complete with release catch 00-HV-D930

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HV-B – drawingsGeneral arrangement drawings of 11kV heavy duty operating handleSeries HV-B


1From drawing MA 1656, showing typical HV-B operating handle variants.

Handle types, for 11kV, 33kV disconnectors

00-HV-B10, standard tee.00-HV-B10E, same as B10, but with earth strap.00-HV-B20, spade grip.00-HV-B30, standard tee, 25NB operating pipe.00-HV-B40, spade grip, 25NB operating pipe.00-HV-B60, plain, less tee.

The handle’s pipe clamp accepts 15NB or 20NB operating pipe, except for those models indicated abovewith 25NB clamps.

Also available with all stainless steel fasteners – replace the last zero of the product reference with a five, e.g. 00-HV-B15, standard tee, with s/s fasteners.

For heavy duty station class operating handles, type HV-D, please refer to the facing page.

HV-D – drawingsGeneral arrangement drawings of heavy duty, pump type, stationclass, operating handle, Series HV-D

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Handle types, for station class disconnectors00-01092-410, (HV-D410), 4” radius, provision for auxiliary switch only.00-01092-610, (HV-D610), 6” radius, provision for auxiliary switch only.00-01092-630, (HV-D630), 6” radius, provision for auxiliary switch and00-01092-640, (HV-D640), 6” radius, provision for auxiliary switch and key deadlock.00-01092-910, (HV-D910), 9” radius, provision for auxiliary switch only.00-01092-930, (HV-D930), 9” radius, provision for auxiliary switch and

Also available with all stainless steel fasteners – replace the last zero of the product reference with a five, e.g. 00-01092-615 (i.e. HV-D615).

From drawing MA1092, showing typical HV-D operating handle, with optional type HA-AG auxiliary switchunits and key deadlocks fitted.Auxiliary switches and deadlocks only supplied when requested.

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HA-AU ( ) D – drawingsGeneral arrangement drawings of auxiliary switch cabinet Series HA-AU 8 D, fitted to a heavy duty operating handle, Series HV-G


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Auxiliary switch cabinets, for station class disconnectors00-03978, HA-AU 8 D, auxiliary switch cabinet, for HV-G operating handles.00-03979, HA-AU 10 D, auxiliary switch double cabinet.

From drawing 4500:610, showing type HA-AU8D auxiliary box assembly, fitted to a typical HV-G operatinghandle. A double switch cabinet is also available.Auxiliary switches and deadlocks combinations are also available.

HA-AT-D – drawingsgeneral arrangement drawings of rotary auxiliary switch unit SeriesHA-AT-D, for fitting to rotary disconnector switch handles

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Rotary auxiliary switch unit, for station class rotary type disconnectors00-03329-020, HA-AT-D, rotary auxiliary switch unit

From drawing 3329, showing type HA-AT-D auxiliary switch unit.

80251MV_HVsection1

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