sq d-elect aapp'n guide

Electrical application guide

Square D application guide general introduction

use the guide

Why

to use the guide

Where

The Square D Application Guide has been developed to assistanyone who has an interest in or takes part in designingelectrical distribution systems.

The guide starts with single phase distribution where the needfor discrimination within the system and requirement of back upprotection devices is limited. In this section the application andoperation of products which protect against overloads, shortcircuits, earth faults and system overvoltage protection areexplained.

When designing distribution systems for commercial andindustrial buildings much more consideration must be given tothe security of the supply within the system and understandinghow discrimination is achieved with the higher prospective faultlevels which exist in these systems.

The guide also explains the use of Control and Commandproducts and how to utilise them within the distribution systemfor more automatic cost savings and better use of the supply.

in the guide

WhatsSection 1 Residential solutions for single phase

distribution

Section 2 Commercial and Industrial solutions forthree phase distribution

Section 3 Control and Command for largecommercial applications

Section 4 Tabulation of tables and figures for all sections

Sec1 1

Residential solutions for single phase distribution 1

introduction

Section 1

section 1

Contents

Distribution within a residential application generally requires a single unit for the incoming supplyand protection of individual circuits, the need to discriminate with downstream devices other thanresidual current devices is not normally a requirement within residential applications. The correctunderstanding on the way miniature circuit breakers, residual current devices and surge protectionoperate can help to minimise costs and contribute towards a system that operates efficiently.

The consumer unit or A type single phase distribution board houses the protection devices and initself has a number of variations which correctly chosen can also help the designer produce asystem which meets the needs of the end user and installer.

Consumer units

Protection design and use

Miniature circuit breaker protection

Earth leakage protection

Surge protection

Control of the installation

Specifications

MCB

L

N

Switch

2 Sec1

Simple distribution for a single dwelling

Residential solutions for single phase distribution

1Safety in built asstandard

Everyone involved in theconstruction or maintenanceof residential premises,recognises the importance ofsafe and reliable electricalsystems. Square D is noexception and has ensuredthese requirements are inbuiltinto their products asstandard, safeguarding thosewho use electricity in andaround the home.

Exceeding expectationsfor quality andperformance

At Square D we take great pridein the quality of all our products.As a result weve ensured thatQwikline II meets therequirements of the followinglocal and in some casesinternational standards.

BS EN 60439-3 consumer unitsMeets all the designrequirements of this localstandard while additionallyhaving been subjected to 16kAconditional short circuit faults toprove the products effectivenesseven at extreme fault levels.

BS EN 60529 ingress protectionIP2XB protection ensures a highlevel of protection againstaccidental direct contact with live parts even with the covers removed.

In addition the following standards found within the Qwikline IIportfolio prove the performance of our devices under range ofarduous conditions.

BS EN 60947-3Switch disconnectors.

BS EN 60898Miniature circuit breakers (MCBs).

BS EN 61008Residual current circuit breakers (RCCBS)

BS EN 61009Residual current circuit breakers with overcurrent protection(RCBOs)

Solutions flexibleenough to meetcustomers changingneeds

Regardless of the type or sizeof dwelling, Square DsQwikline II consumer unit issuitable for single or multi-occupancy dwellings. Inaddition, Qwikline II consumerunits can accommodate arange of Square D controlproducts such as belltransformers or timed circuitsproviding the designer withunobtrusive, user friendlyapplications. These controlproducts can be installed inthe consumer unit before orafter occupancy.

Sec1 3Residential solutions for single phase distribution

Designs of consumer units 1They are available in an insulated or sheet steel. One of 3 types of consumer unit are normally installed.However, many variations can be offered including Multi-tariff, for single phase applications where theperformance required exceeds that of a consumer unit A type distribution boards may be used*.

Technical terms explained

MCB - Miniature Circuit Breaker. Page 6 Section 1

RCBO - Residual Current Circuit Breaker with overcurrent protection. Page 18 Section 1

RCCB - Residual Current Circuit Breaker. Page 17 Section 1

RCD - Residual Current Device. Page 16 Section 1

1 Standard

Will have a switch with a redhandle, or an RCCB on theleft and several MCBs /RCBOs to the right of it. Eachdevice should be clearlylabelled above it to say whichcircuit the device protects, i.e.Shower, Ground floor sockets,First floor lighting, etc.

2 Split load

As with a standard boardthese will be a switch orRCCB on the left but thebusbar will also feed an RCCBin the centre of the consumerunit. All devices to the right ofthis RCCB are provided with ahigher level of protectionagainst electric shock and willtypically be providing powerfor socket outlets in the home,garage and garden. Thecircuits supplied by the RCCBare designated as protectedcircuits, i.e. personnel or fireprotected. Those supplied bythe incomer are designated asnon-protected.

3 Dual incomer

A house converted into flatsor needing more than onemeter (e.g. a reduced tariff onelectric heating), may have aDual incomer board. This islike having two standardboards in one. The switch onthe left will isolate MCBsimmediately to the right of it,up to the next switch. Thesecond switch (in the centre)will isolate the remainingMCBs, also to the right i.e.supply two. A multi tariffconsumer unit works on thesame principle but will havethree or more separatesections. Each section shouldbe clearly marked to showsupply A or B etc. Thesections may also beprotected by an RCCB.

* See page 42 for A type distribution boards

4 Sec1

Protection design and use


1Switch disconnector(Switch)

This is the switch on the far left-handside and has a red toggle. When theswitch is in the OFF position (toggledown) all power to the house will beoff and the house will be totallyisolated.

The switch must be of thedisconnector type and isolate both thelive and neutral conductors.

How do these devices inside the consumer unit work?.

You may have up to five different types of device in the consumer unit.

Miniature circuit breaker(MCBs)

Each MCB in the consumer unit isresponsible for protecting differentcircuits against electrical faults. Thesecould happen by plugging in too manyappliances or short circuit by cuttingthrough a cable.

For example, one circuit breaker willprotect the ground floor lights, anotherthe immersion heater and another themains operated smoke alarm. Theconsumer unit should be clearlylabelled which MCB protects each areaof the electrical network, either bywriting in the space provided or byusing sticky labels.

Square D MCBs also fulfil thefunction of a switch disconnector forisolating the live outgoing circuit.

Residual current circuitbreakers withovercurrent protection(RCBOs)

An RCBO is the same width as anMCB but will have a test button underthe toggle. It combines the sametechnology as an MCB and an RCCBtherefore provide the highest levels ofprotection available on the markettoday.

It is recommended that RCBOs aretested monthly by pressing the testbutton. When the test button is pressedthe device should trip and go into theoff position. A label should be fixed tothe consumer unit to show that theinstallation or part of it is protected bya residual current device.

Square D RCBOs also fulfil thefunction of a switch disconnector forisolating the live outgoing circuit.

Residual current circuitbreaker (RCCBs)

An RCCB can easily be spotted in theconsumer unit. It will be the width oftwo MCBs with a black test buttonabove the toggle. If you have a splitload consumer unit then you will havean RCCB in the middle of yourconsumer unit. This will provideresidual current protection to all thecircuits to the right of the device.Most probably this will be sockets,garage, shower or electric oven.

Residual current protection meansthat you are protected against thedangers of electric shock and havingan RCCB or RCBO installed meansthat the home is potentially protectedagainst the outbreak of fire throughelectrical fault. A label should be fixedto the consumer unit to show that theinstallation or part of it is protected bya residual current device.

The RCCB must be of the disconnectortype and isolate both the live andneutral conductors.

Surge protection

The use of a surge protection deviceis recommended where a riskassessment has been carried out andthe probable cost of lightning strike ishigh.


Protection design and use 1Circuit diagram for a split-load consumer unit.

RCCBN L

MCB MCB MCB MCB MCB MCB MCB MCB

Additional controlproducts may befitted as required

Fig. 1

Table 2Maximum fault loop impedance in Ohms for circuits protectedby types B, C and D MCBs

MCB rating Type of MCBAmps B C D

Ohms Ohms Ohms3 15 7.7 3.86 7.7 3.8 1.910 4.6 2.3 1.1516 2.9 1.4 0.7220 2.3 1.15 0.5725 1.84 0.92 0.4632 1.4 0.72 0.3640 1.15 0.57 0.2850 0.92 0.46 0.2363 0.72 0.36 0.1880 0.58 0.29 0.14

6 Sec1

MCB tripping curves


1For each rating of MCB (10amp, 20 amp, 40 amp etc)three distinctly different typesof MCB are specified in BS EN60898 - types B, C and D. Thedifference between these typesrelates to the instantaneoustripping characteristics.

The levels of overcurrentrequired for instantaneoustripping for the three maintypes of MCB are shown inTable 1.Table 2 lists the fault loopimpedance values thatcorrespond with the currentrequired to ensure tripping ofMCBs within the requirementsspecified in Chapter 41Protection Against ElectricShock in the Wiring Rules.As will be seen from thetripping curves, MCBs aredesigned to trip within 0.1seconds in short circuitconditions and it is not,therefore, necessary todifferentiate between the twocategories of tripping times(0.4 sec and 5 secs).Consequently, unlike tables ofmax. loop impedance for fuseswhich quote different figuresfor 0.4 sec and 5 sec tripping,tables for MCBs such as Table2 can apply to bothsocket/portable appliancecircuits (0.4 sec tripping) andfixed equipment circuits (5 sectripping). Check theperformance figures for exactdetails.

Another feature evident fromthe tripping curves is that thedifference between B, C and Dcharacteristics relate only tothe magnetic/solenoidcomponent of these devices,i.e. the component thatprotects against short circuit.The portion of the trippingcurve relating to overloads(influenced by the thermalcomponent) is virtually thesame for B, C and D devices.The selection of a suitable typeof MCB is an important factorin the design of a circuit toensure protection againstelectric shock, i.e. to ensurethat the protective device tripswithin the required time in theevent of a fault to earth. Therequired conditions will be metif the circuit loop impedance iswithin the maximum permittedlevel, as shown in Table 2.

Table 1Current required for instantaneous tripping to BS EN 60898

MCB type Multiple of rated currentB 3 - 5 timesC 5 - 10 timesD 10 - 20 times

Curve type B is the onenormally chosen forresidential use with type Cand D generally used forcommercial or industrialpremises

MCBs for residential usewould normally have abreaking capacity of notless than 6,000A and notless than 10,000A forcommercial or industrialuse

Note: Where the earth loop impedance is too high for the MCB to meet tripping times, an RCBO is recommended.


MCBs - definition of curves (BS EN 60898) 1Curve BProtection of generators, longcables, heating loads,tungsten lighting and persons(on TN and IT neutralsystems), residential.

OverloadsStandard thermal protection.

Short circuitsFixed magnetic curve B (Im between 3 and 5 In).

Curve CProtection of cables supplyingloads with relatively highswitching surges e.g.discharge lamps and somemotors.


Short circuits Fixed magnetic curve C (Im between 5 and 10 In).

Curve DProtection of cables supplyingloads with high switch onsurges.


Short circuitsFixed magnetic curve D (Im between 10 and 20 In).

External overloadprotection using a bi-metallic elementprovides close overloadprotection for cables.

Magnetic protectionusing a solenoid meansa fast operation during aphase/neutral orphase/earth short circuit.It reduces electricalstress in the system andhelps meet thedisconnection times forelectric shockprotection.

t

In3 5 10 20

Curve BCurve C

Curve D

2

11. Thermal: Overload

2. Magnetic: Short circuit (Im)

2

Fig. 2

Fig. 3

1

8 Sec1

SQO residential MCB performance figures


1Type B MCBs

Rating (A) Zs ohm @ 230V ac R25s 0.4s ohms

3 15 15 3.336 8 8 1.6710 5 5 1.0016 3 3 0.6320 2.3 2.3 0.5025 1.8 1.8 0.4032 1.4 1.4 0.3140 1.2 1.2 0.2550 0.9 0.9 0.2063 0.76 0.76 0.18

Type C MCBsRating (A) Zs ohm @ 240V ac R2

5s 0.4s ohms3 15 8 3.336 8 3.8 1.6710 5 2.3 1.0016 3 1.4 0.6320 2.3 1.2 0.5025 1.8 0.9 0.4032 1.4 0.7 0.3140 1.2 0.6 0.2550 0.9 0.5 0.2063 0.38 0.76 0.08

Earth loop impedance values.

Table 3


SQO residential MCB performance figures 1

Type C MCBs

3060100160200250320400500630

3060100160200250320400500630

3060100160200250320400500630

203966105132165211263329517

15.831.55384105131168210263410

1225416682103131164205315

10.721.536577290115143179265

9.41931506379100126157221

7.5152540506380100125173

6.513223544557087109151

612203240506480100139

5.41118293645587290126

4.89.616263240516480110

4.38.614.323293646577295

3.981321263342526585

3.87.612.620.225.23240506383

3.77.412.419.824.83139.749.66282

3.671219243038486081.3

0.005 0.6 1 2 3 5 7 10 20 30 40 60 100 200 500 1000 2000 10000Disconnection time in seconds (s)

Disconnection current (A)

SQO103EC6SQO106EC6SQO110EC6SQO116EC6SQO120EC6SQO125EC6SQO132EC6SQO140EC6SQO150EC6SQO163EB6

Disconnection times.

Table 4

Type B MCBs

15305080100125160200250315

15305080100125160200250315

15305080100125160200250315

15305080100125160200250315

15305080100125160200250315

12.325416682103131164205315

10.721.536577290115143179265

9.41931506379100126157221

7.5152540506380100125173

6.513.1223544557087109151

612203240506480100139

5.410.818293645587290126

4.89.616263240516480110

4.38.614.323293646577295

3.97.81321263342526585

3.87.612.620.225.23240506383

3.77.412.419.824.83139.749.66282

3.67.212192430384860213

0.005 0.6 1 2 3 5 7 10 20 30 40 60 100 200 500 1000 2000 10000Disconnection time in seconds (s)


SQO103EB6SQO106EB6SQO110EB6SQO116EB6SQO120EB6SQO125EB6SQO132EB6SQO140EB6SQO150EB6SQO163EB6

10 Sec1

SQO residential MCB performance figures


1Type B MCBsRating (A) Short circuit level

(kA)2 6I2t (x1000)

3 4 96 4 910 6 1716 7 2320 7 2325 7 2332 10 32.540 10 3550 13 3563 13 35

Type C MCBsRating (A) Short circuit level

(kA)2 6I2t (x1000)

3 4 96 4 910 6 1716 7 2320 7 2325 7 2332 10 32.540 10 32.550 13 3563 13 35

Short circuit levels.

Table 5


SQOR residential RCBO performance figures 1Type B RCBOsRating (A) Zs ohm @ 230V ac R2

5s 0.4s ohms6 1667 1667 166710 1667 1667 166716 1667 1667 166720 1667 1667 166732 1667 1667 166745 1667 1667 1667

Table 6

Table 8

Table 7

Earth loop impedance values. Short circuit levels.

Type B RCBOsRating (A) Short circuit level

(kA)2 6I2t (x1000)

6 4 910 6 1716 7 2320 7 2332 10 32.545 10 32.5

Type B RCBOs

305080100160225

305080100160225

305080100160225

305080100160225

305080100160225

305080100160225

25426784134189

21355670112158

16.528445588124

14.424384877108

13.22235447099

122032406490

10.517.528355679

91524304868

8.113.521.6274361

7.81320.82641.658.5

7.712.920.625.841.358.1

0.005 0.6 1 2 3 5 7 10 20 30 40 60 100 200 500 2000 10000Disconnection time in seconds (s)


Cataloguereference

SQOR106B03SQOR110B03SQOR116B03SQOR120B03SQOR132B03SQOR145B03

Disconnection times.

12 Sec1

Square D circuit breaker application data


1Fixed equipment, disconnection occurs within 5 seconds @ Vac = 230Socket outlets, disconnection occurs within 0.4 of a second

Circuit breaker instantaneous trip type C ( In )Item Catalogue Current Disconnection Time in seconds ( S ) Zs ohm@ R2 Short Circuit level (kA)

Number Rating 0.005 0.6 1.5 2 3 5 7 10 20 30 40 60 100 200 500 1000 2000 10000 230 Vac 2 4 6

A Disconnection Current ( A ) 5s 0.4s Ohms I2t(x1000 )

1 DOM06C6 6 60 60 60 49 39 30 25 21 16.5 14.4 13.2 12 10.5 9.0 8.1 7.9 7.8 7.7 7.67 3.8 1.67 4 7 9

2 DOM10C6 10 100 100 100 82 65 50 42 35 28 24 22 20 17.5 15 13.5 13.2 13 12.9 4.60 2.3 1.00 6 12 17

3 DOM16C6 16 160 160 160 131 104 80 67 56 44 38 35 32 28 24 21.6 21.1 20.8 20.6 2.88 1.4 0.63 7 16 23

Circuit breaker instantaneous trip type B ( In )Item Catalogue Current Disconnection Time in seconds ( S ) Zs ohm@ R2 Short Circuit level (kA)

Number Rating 0.005 0.6 1.5 2 3 5 7 10 20 30 40 60 100 200 500 1000 2000 10000 230 Vac 2 4 6

A Disconnection Current ( A ) 5s 0.4s Ohms I2t(x1000 )

1 DOM03B6 3 15 15 15 15 15 15 12.6 10.8 8.3 7.2 6.6 6 5.3 4.5 4.1 4.0 3.9 3.9 15 15 3.33 4 7 9

2 DOM06B6 6 30 30 30 30 30 30 25 22 16.5 14.4 13.2 12 10.5 9 8.1 7.9 7.8 7.7 7.7 7.7 1.67 4 7 9

3 DOM10B6 10 50 50 50 50 50 50 42 36 28 24 22 20 17.5 15 13.5 13.2 13 12.9 4.6 4.6 1.00 6 12 17

4 DOM16B6 16 80 80 80 80 80 80 67 58 44 38 35 32 28 24 21.6 21.1 20.8 20.6 2.9 2.9 0.63 7 16 23

5 DOM20B6 20 100 100 100 100 100 100 84 72 55 48 44 40 35 30 27 26.4 26 25.8 2.3 2.3 0.50 7 16 23

6 DOM32B6 32 160 160 160 160 160 160 134 115 88 77 70 64 56 48 43 42 41.6 41.3 1.44 1.44 0.31 10 23 32.5

7 DOM45B6 45 225 225 225 225 225 225 189 162 124 108 99 90 79 68 61 59 59 58.1 1.02 1.02 0.22 10 23 32.5

8 DOM50B6 50 250 250 250 250 250 250 210 180 138 120 110 100 88 75 68 66 65 64.5 0.92 0.92 0.20 13 28 35

Table 9

Table 10


Earth leakage - the risks and their consequences 1Electrocution

A few milliamps is suffice toseriously harm the humanbody. Electrocution canoccur either by direct contactwith an electric cable or a livedevice, or by indirect contact,if the person touches anaccidentally energised metalpart.

All electrical installations produce current flow. Even small current flow presents risks which can cause serious damage.

The physiological reaction

Depends on:

The contact voltage

The type and duration ofthe contact

The age and vulnerabilityof the subject

Fire

30% of fires in industrial anddomestic buildings are theresult of an electrical fault, themain cause of which isdeterioration of cableinsulation due to overheatingor accidental damage.

Load destruction

Some electrical devicesdeteriorate over time and maypresent insulation faults.Insulation faults have manycauses:

Heat generated by deviceoperation

Overcurrent

Aggressiveness of theenvironment

Material wear and loss oftightness

Apart from load destruction,there is a risk of electrocutionand fire.

300mA Cardiac arrest75mA Irreversible cardiac

fibrillation threshold30mA Respiratory paralysis

threshold10mA Muscular contraction0.5mA Very slight sensation

Fig. 4

14 Sec1

How to protect people and equipment from earth leakage


11. Prevention: Prevent the fault fromoccurring

The approach concernsprimarily new electricalinstallations. Technicalprogress and application ofstrict standards are a majorasset for the commissioningof efficient, reliableinstallations.

Installations should complywith BS 7671 (wiringregulations) and have thecorrect selection of devicessuch that in the event of anearth fault, sufficient currentwill flow to trip the devicewithin the stated time period.

2. Action: Detect and neutralise faults

The solution: The Square Drange of earth leakageprotection products.

RCCB

2 poles

Rating: 63 - 100A

Voltage rating: 230Vac

Sensitivity: 30 - 300mAInstantaneous/selective

AC class

When confronted with the risk of electrocution, destruction of loads and fire, twodifferent but complementary approaches provide effective protection.

RCBO

1 pole

Rating: 16 - 45A

B curve

Voltage rating: 230Vac

Sensitivity: 30mAinstantaneous

AC class


How does earth leakage protection work 1The principle of Square D earth leakage protection is based on a system performing three successive functionsvirtually instantaneously: detection of a leakage current, measurement of this current and trip opening of thefaulty circuit.

Detection

A current transformer is usedwhose primary windings arethe phase(s) and the neutral ofthe circuit to be protected.The winding direction is suchthat the load and neutralcurrents cancel one anotherout. The appearance of aleakage current destroys thisbalance and generates acurrent at the secondarywinding known as a residualcurrent.

Measurement

An electromechanical relay isused which compares theelectric signal to a pre-setlimit: the tripping threshold,also known as sensitivity.

A permanent magnet holdsin the closed position aswivel plate connected to atripping mechanism

Opposite this, anelectromagnet supplied bythe residual current, and ataut spring have a jointeffect on plate opening

As long as the strength of thepermanent magnet (definedaccording to required systemsensitivity) is greater than thatof the spring and theelectromagnet, the circuit isclosed.

Tripping

As soon as the residualcurrent is high enough tocancel the effect of thepermanent magnet, the springcauses the plate to swivelwhich then strikes the tripopening mechanism of thefaulty circuit.

Leakage current risks

An occasional earth leakagecurrent greater than merely500 mA can generate asufficient overcurrent for theinsulator to heat, melt andstart stripping the conductor.

The leakage current flowingthrough the damagedinsulator creates an electricarc the intense heat of whichignites the insulator and maystart a fire.

Returncurrent

Outgoingcurrent

Current variation = 0

Detection

S N

Measurement

Current variation = 0

S N

Tripping

Returncurrent

Outgoingcurrent

Current variation 0

Fig. 5

Detection Measurement Tripping

16 Sec1

An electromechanical trip or an electronic trip


1 A residual current device

with electromechanical relayfor unmonitored distribution(domestic applications andequivalent)

A residual current devicewith electronic relay formonitored distribution(applications benefiting from a maintenance service,i.e. residential homes)

1. The residual currentdevice withelectromechanical relay(Fig. 6)

This device operates withoutany auxiliary source of supply.The energy supplied by thetoroid energises anelectromagnet whose movingpart is maintained in theclosed position by apermanent magnet.

Fault current energy is thedirect cause of tripping.This is the most reliabletechnology as it worksregardless of fault origin

User safety is top priority,and should not bedependent on quality ofthe network(public/private), installationage, the neutral systemchosen or the mechanismreset

Useful for protectinggroups of circuits in asingle installation

S N

Tripping

Returncurrent

Outgoingcurrent

Current variation 0 N L

S N

Tripping

Electronicrelay

Leakagecurrent

N L

2. The residual currentdevice with electronicrelay (Fig. 7)

This device operates with anauxiliary source of supply. Theelectrical energy supplied bythe toroid is amplified by theelectronic board, in turnsupplied by a sourcedependent on networkvoltage.Fault detection causes thebreaking device to trip. Thesedevices may be completelyindependent, built into ormounted on the breakingdevice.

High setting dynamicsensuring continuity ofsupply

A solution that can be usedon all feeder typesirrespective of their rating

Useful for outgoing devicesas it is the same width asan MCB and may beinterchanged

Fig. 7

Fig. 6

RCCB

RCBO

B

A

Square D utilises two technologies:electromechanical and electronic. The technologicalchoice depends on the specific features of yourinstallation.In compliance with the standard, Square D uses:


Residual current circuit breakers - RCCB 1Operating principle

In addition to leakage currentdetection, the residual currentcircuit breaker can be used toswitch or isolate a circuit.

It has no short circuit oroverload protection, and assuch must be protected by anupstream circuit breaker. Itsmain function is to protect aset of feeders, each equippedwith circuit breakers. Use ofthe residual current circuitbreaker is recommended toprovide earth leakageprotection of an installationequipped with circuitbreakers.

Consequently, particularlyused for domestic,commercial and smallindustrial applications, itsadvantage is that it canprovide complete safety ofsensitive circuits at a low cost,for example in a kitchen orbathroom, a shop where thereare risks for customers, dampworking premises andpremises with an aggressiveenvironment.

They may also be use toprovide individual protectionto existing circuits either onthe outgoing or incomingcircuits of a consumer unit.

Technical data

Unwanted tripping

All the Square D residualcurrent circuit breakers areimmunised by an interferencesuppression device whichremoves the risk of nuisancetripping caused by:

Sudden voltage variations(atmospheric overvoltages,device switchings)

Current variations (Highlycapacitive circuits)

The residual current circuitbreakers meet currentstandards:

BS EN 61008

Fuse cutout

Consumer unit incomer

RCCB fitted externallyor replacing incomer

MCB MCB MCB MCB MCB

Fig. 8

18 Sec1

Residual current breaker with overload protection - RCBO


1

Switchdisconnector

RCBO RCBO RCBO RCBO

Operating principle

The RCBO combines thecircuit breaker and residualcurrent circuit breakerfunctions in the same device.

It thus provides completeprotection against shortcircuits, overloads andinsulation faults. Suchversatility means it canadvantageously be used in allapplication types. The mainapplication of this device isthe protection of faults andthus to guarantee increasedcontinuity of supply to non-effected circuits.

Consequently, for specialcircuits and to ensure healthycircuits are not effected by afault for instant on a socket.Each level can be protectedby a suitable residual currentdevice according to itsposition and degree of risk.

Technical data

The RCBO one piece deviceprovides:

Complete protection offinal circuits (over currentsand insulation faults)

Protection of personsagainst indirect contact(30mA) or direct contact

With the 30mA sensitivity,total vertical discriminationif they are installeddownstream of a 300mA Sselective residual currentdevice

Square D RCBOs may beused to disconnect the lineside and isolate the circuit

The Square D RCBO meetscurrent standards:

BS EN 61009

Fig. 9


Protecting LV installations against lightning overvoltages 1A surge arrestor is a devicethat limits transient voltagesurges and runs currentwaves to ground to reduce thestrength of the voltage surgeand make it safe for electricalinstallations and equipment.

The surge arrestor eliminatesvoltage surges:

In common mode: betweenphase or neutral and earth

In differential mode:between phases andneutral

The unit consists of a zincoxide varistor having a veryfast response time, in theorder of one nanosecond (10-9 s) with high energydissipation. Immediately afterthe surge the device revertsback to its normal highimpedance state.

The surge arrestor has aninternal thermal protectiondevice which guards againstburn out at the end of its life.Gradually over normal use,after withstanding a number ofvoltage surges, the surgearrestor degrades into aconductive device. Anindicator on the front warns ofthis approach of end-of-life.When new this indicator iswhite; at end of life itbecomes red. The protectingMCB operates to disconnectthe device from the supply.

The decision to fit surgesuppression to an electricaldistribution system should bebased on a risk assessmentand the type of equipmentinstalled on site which may beeffected. The increased use ofelectronic equipment withinthe home may make the useof surge protection advisable.

The following is a method ofassessing the need for surgesuppression.

20 Sec1

Surge protection - applications


1How to choose surge arrestors.

To protect loads againstatmospheric overvoltages, thefollowing must be taken intoaccount:

The impulse withstandvoltage of the equipmentto be protected (Uchoc)

The maximum voltage (Uc)of the supply network andof the earthing system

The lightning stroke densityThe surge arrestors level ofprotection (Up) must thereforebe:

Uc (network) < Up (surgearrestor) < Uchoc (load)

Based on the above the surgearrestor and its associatedcircuit breaker can beselected

Impulse withstand (wave 8/20) table for equipment to be protected in a three phase network under230/440V as in standard IEC 60364-4Impulse withstand Category I Category II Category III Category IVVoltage category Reduced Normal High Very highType Electronic circuit Household Industrial Industrial

device appliances devices devicesTelevision, alarm, Dishwasher, Motor, Electric meter, remote Hi-Fi, oven, refrigerator, distribution cabinet, measurement devicevideo recorder, hand tools current sockets,computer and transformertelecommunicationequipment

Uchoc (Impulse withstand voltage)Examples 1.5kV 2.5kV 4kV 6kV

Earthing system maximum voltageType of earthing system TT TN-S TN-C

Uc (network) maximum voltage 345/360V 253/264V 253/264V

Please contact us forinformation on the latest rangeof surge arrestors for lowvoltage networks.

Table 11


Surge protection - operational information 1Surge arrestor installation rules.

Must be installed as nearas possible to the mainincoming device

Must be protected by asuitable circuit breaker

Cable length from breakerto surge arrestor and toearth bar must be less than500mm for maximum effect

MCB Surge Arrester

L1 N

Fig. 10

22 Sec1

Control and Command - lighting control


1

Manual control

This circuit shows thesimplest form of control. A manual switch controls thelighting. This arrangement isadequate if the load is small,the cable runs are short andpeople can be relied upon toturn the lights out when theyare not needed.

(Fig. 11)

Automatic control

The introduction of some formof automatic control canreduce electricity costs andsimplify the total electricalinstallation. Whilst automationin some form may add to theinitial installation costs, thishas to be balanced againstthe electricity consumptioncosts over the life of theelectrical installation.

Products that may be used toautomate the installation, inpart or fully, are

Time switches

Passive infra red detectors

Presence detectors

Contactors

Light sensitive switches

Bi-stable relays

All these devices may be usedindividually or in combinationto provide the best possibleinstallation to suit the needs ofthe occupants.

(Fig. 12 and 13)

MCB

L

N

Switch

MCB Time Switch

L

N

ON/OFF

ON/Timed

Time SwitchMCB

L

N

Since the introduction of the Climate Change Levy, wasting energy is not just bad for the environment: it now carries a heavy financialpenalty, with electricity the most heavily taxed fuel of all. But with a Square D consumer unit or distribution board, you have access toa unique range of Control and Command devices designed to make savings in every area of consumption and ensure comfort for theuser.

Fig. 11

Fig. 12

Fig. 13


Control and Command - lighting control 1Time switches

Typical applications are retailtrading areas where the mainlighting is required to beswitched at set times eachday without the need formanual intervention.

The type of time switch to beused depends upon the levelof sophistication required.

Simple 24 hour time switch,repeating the same pre-setswitching sequence each day.Battery back up is included toeliminate the need to reset thedevice every time there is apower cut.

Digital time switch, 7 daytype. These are available with1 or 2 programmablecontacts.

The program can be set tohave different switching timeseach day or day omission ifrequired. e.g. no switching atweekends. The two contactsof the 2-channel version canbe programmed completelyindependently. Battery backup stores the switchingprogramme for at least 5years.

(Fig. 12)

Presence and PIRdetectors

Both of these devices can beused to control lighting buttheir functions are verydifferent.

Presence detectors are usedto turn lights ON when peopleare present in the room and toturn them OFF when the room is unoccupied.Normally ceiling mounted theydetect human presence. Theiruse saves energyconsumption. They areintended for use in offices,corridors or where areas arenot permanently occupied.

PIR detectors most obvioususe is for security purposes toswitch external lighting ONwhen movement is detectedwithin the sensing area. Thisarea is an arc of up to 180with a radius of 12 metres.

Multi function time switch,having 4 independentlyprogrammable time contacts.Each contact can have aconditional input associatedwith it. In addition ON delaysand OFF delays, hourscounters and switchingcounters can be incorporated.The programme is stored in acartridge which enables theprogramme to be copied toanother device.

Control by light sensitiveswitch, this device enableslighting to be switched, notaccording to time butaccording to the level ofdaylight. The threshold can beadjusted to determine the light level below which thelighting is switched ON. Thismay be used with external orinternal lighting.

An ON / OFF override facilityexists on the time switches.On the digital devices thisoverride can be temporary,until the next switch operationor permanent. To preventunauthorised access to thetime switch and possibletampering it may be preferredto have external ON / Timed /OFF control.

This switching arrangementcan be achieved by using astandard 2-gang single poleone way light switch. Thesupply to the time switchmotor is maintained. On loss of supply the timeswitch will continue to keeptime but the contacts will notswitch.

(Fig. 13)

24 Sec1



1Larger lighting schemes

The previous lighting schemesare very effective in the smallenvironment but as thelighting load increases and thefloor area to be lit increasesso does the electrical load. Inaddition, the longer cable runsintroduce greater voltagedrops making the need forlarger cables more likely.Whilst it may seem a paradoxto introduce morecomponents to simplify thearrangement, the use ofcontactors in the lightingcircuits makes the installationeasier to install and simpler tocalculate. Voltage dropcalculations are greatlysimplified as the switchingcircuit is not part of the maincircuit. This main circuit isdirect from the distributionboard to the luminaries. Theswitching circuit only carriesthe load of the contactor coil,which at switch on is of theorder of 0.2A.

A separate control circuit mcbis required if the main mcb isof such a rating that it doesnot protect the control circuitcable against overcurrent.

(Fig. 14)

Contactor control is essentialwhen the lighting is controlledby BMS system. The controlcircuits are run from thedistribution boards to theBMS controller that may bepositioned whereverconvenient for the operationof the building.

Time switches, presencedetectors and PIR detectorscan all be used with contactorcontrolled circuits. Thesecontrolling devices are allconnected in the switch circuitso only carry and switch thecontactor coil current givinglonger contact life.

Controlling devices can becombined to provide moresophisticated control. Thesecombinations are much easierwith contactor control.

e.g. Combine light sensitiveswitch & time switch: withtheir contacts connected inseries they ensure that lightsare only on during permittedhours and when the naturallight level is below the setthreshold, i.e. carparks.

Whether the main lighting loadis single or 3 phase, only oneset of control devices isrequired.

Apart from the light sensitiveswitch sensor, all thecomponents and wiring iscontained in the distributionboard.

(Fig. 15)

MCB

Main

Control

L

N

Contactor

MCB

L

NSwitch

ControlMCB

LightSensitiveSwitch

Time Switch Contactor

L

N

Fig. 14

Fig. 15


Control and Command - lighting control 1Stairwells

Stairwells and hallways needto be well lit whilst people arepresent but as the areas areonly occasionally occupiedenergy is wasted by leavingthe lights on permanently.

Use a timer relay to switch thelights ON when required andthen to switch OFFautomatically after a timedelay.

With the location of switchesat every point that peoplewould use to enter thestairwell it is easy for users toswitch the lights ON.

The period that the lights stayON can be set between 1 and7 minutes. The switches needto be pushbutton (retractive)types. If required they may befitted with a neon indicator,wired across the contacts, toaid location in the dark.

(Fig. 16)

Installation costsGenerally the extra cost of theadditional components in theelectrical distributionequipment will be recoveredmany times over by thereduction in electricityconsumption over the life ofthe installation.

Control and commandproducts may be fitted atunused ways in the consumerunit.

For stand alone controlapplications or where there isinsufficient space within theunit a range of insulated andmetal enclosures are available.

Run on timer

The circuit is designed toswitch lights and anassociated ventilation fan. Onclosing the switch the lightsand the ventilation fan areswitched ON. When theswitch is opened the lights goout but the fan continues torun for a period of time,adjustable between 1 and 7minutes.

(Fig. 17)

L

Timed

Pushbutton

Additional pushbuttons may be connected in parallel

MCB

N

L

Switch

Timer

MCB

Fig. 16

Fig. 17

26 Sec1



1This circuit provides lighting for a short time so that electricity is not wasted byaccidentally leaving the lights on permanently.

The lights are switched ON bya pushbutton suitably located

either inside or outside thepremises. The lighting remainsON for a period of time andthen switches OFFautomatically. This time canbe set for any time up to 7minutes.

More than one light switchcan be used: the normallyopen

contacts on each switchshould be wired in parallel.Because the switches onlycarry control current they canbe located as far from thepremises as necessary e.g.either end of a drive, withoutvoltage drop problems.

Note: Standard light switchesmust not be used.

The circuit to the luminairesmust be sized and designed inaccordance with BS7671.

The function is achieved byfitting a delay OFF timer in theconsumer unit. It occupies thesame amount of space as asingle pole MCB. Themaximum load is 2000W at240V, 50Hz.

Note: The switch on the sideof the timer unit must be setto position 4.

3P

N 4

Delay off timer

6A MCB

N

L

To otherluminaires(non timedoptional)

To timercontrolledluminaire

Pushbuttonswitches

Fig. 18

Delay off timer

Electronic control fluorescent lamps HFR, HFP with PF correction @ Vac = 230Lamp Circuit Number of lamps in circuitwattage current(W) (A) Circuit breaker type C & D trip


Table for lamps - type C & D trip MCB 11 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

14/18 0.09 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 614 x2 0.15 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 614 x3 0.23 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 10 10 1014 x4 0.29 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 10 10 10 1018 x2 0.18 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 618 x4 0.36 6 6 6 6 6 6 6 6 6 6 6 6 6 10 10 10 10 10 10 1021/24 0.12 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 621/24 x2 0.24 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 628 0.16 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 628 x2 0.28 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 10 10 1035/36/39 0.19 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 635/36 x2 0.34 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 10 10 10 10 1038/39 x2 0.38 6 6 6 6 6 6 6 6 6 6 6 6 10 10 10 10 10 10 10 1040/42 0.21 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 642 x2 0.41 6 6 6 6 6 6 6 6 6 6 6 10 10 10 10 10 10 10 10 1649/50 0.24 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 649/50 x2 0.48 6 6 6 6 6 6 6 6 6 6 10 10 10 10 10 10 16 16 16 1654/55 0.27 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 10 1054/55 x2 0.54 6 6 6 6 6 6 6 6 10 10 10 10 10 10 16 16 16 16 16 1660 0.3 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 10 10 10 10

Electronic control fluorescent lamps non integrated PL-LLamp Circuit Number of lamps in circuitwattage current(W) (A) Circuit breaker type C & D trip

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

18 0.09 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 618 x2 0.16 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 621/24 0.11 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 621/24 x2 0.22 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 636 0.16 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 636 x2 0.31 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 10 10 10 10 1040 0.2 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 640 x2 0.4 6 6 6 6 6 6 6 6 6 6 6 6 10 10 10 10 10 10 10 1055 0.25 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 10 1055 x2 0.5 6 6 6 6 6 6 6 6 6 10 10 10 10 10 10 10 16 16 16 16Table 12

28 Sec1

Control and Command - heating control


1Manual control

The circuit below shows thesimplest form of control. A manual switch controls theheating.

This arrangement is adequateif the load is small and peoplecan be relied upon to turn theheaters off when they are notneeded.

For water heaters the switchmust be within easy reach ofthe heater.

(Fig. 19)

Automatic control

The introduction of some formof automatic control canreduce electricity costs byensuring that heating is onlyswitched on when required.Whilst automation in someform may add to the initialinstallation costs, this has tobe balanced against thereduced electricityconsumption costs over thelife of the electricalinstallation.

Time switches andthermostats are examples ofproducts that may be used toautomate the installation. Theyare installed in the heatercircuit to directly switch theload.

For larger loads the contactrating of these control devicesis not adequate and so it isnecessary to switch the loadusing an interposingcontactor. The controllingdevices switch the controlcircuit of the contactor whichin turn switches the load.

These control devices may beused individually or incombination to provide thebest possible installation tosuit the needs of the end user.

Time switches

Typical applications areresidential areas where theheating is required to beswitched at set times eachday without the need formanual intervention.

The type of time switch to beused depends upon the levelof sophistication required.

(Fig. 20)

Simple 24 hour time switch,repeating the same pre-setswitching sequence each day.Battery back up is included toeliminate the need to reset thedevice every time there is apower cut.

Digital time switch, 7 daytype. These are available with1 or 2 programmablecontacts.

The programme can be set tohave different switching timeseach day or day omission ifrequired. e.g. no switching atweekends. The two contactsof the 2-channel version areprogrammed completelyindependently. Battery backup stores the switchingprogramme for at least 5years.

An ON / OFF override facilityexists on all the time switchesbut it may be preferred tohave external ON / Timed /OFF control.

This allows control withoutgiving access to the timeswitch settings. When theheater is controlled by acontactor this can beachieved by using a standard2-gang single pole one waylight switch. The supply to thetime switch motor ismaintained. On loss of supplythe time switch will continueto keep time but the contactswill not switch.

(Fig. 21)

Contactor control is essentialwhen the heating is controlledby a BMS system. The controlcircuits are run from thedistribution board to the BMScontroller positioned whereverconvenient for the operationof the building.

(Fig. 22)

Generally the extra cost of theadditional components in theelectrical distributionequipment will be recoveredmany times over by thereduction in electricityconsumption over the life ofthe installation if suitablecontrolling products are used.


Control and Command - heating control 1MCB

L

N

Two Pole Switch

Time SwitchMCB

N

L

Two Pole Switch

ON/OFF

ON/Timed

Contactor

Contactor

Time SwitchMCB

L

N

MCBMain Circuit

Control Circuit

L

N

Two Pole Switch

ContactorMCB BMS

L

N

ContactorMCBMain Circuit

L

N

Two Pole Switch

Fig. 19 Fig. 20

Fig. 22

Fig. 21

30 Sec1

Control and Command - time switch for immersion heater


1Having the immersion heater running all day is wasteful of energy, but it can beinconvenient to remember to turn it on and off when needed.

In most households hot wateris required in the morningsfrom 7am to 9am and then inthe evening from 5pm until8pm.

The addition of a time switchin the consumer unit allowsthe heater circuit to beswitched on or off to suit theoccupiers specificrequirements.

The time switch is easilyprogrammed and, being a 7day device, the times set canbe different at the weekends ifrequired.

Time setting interval: 1 minute.

Note: The circuit cable mustbe sized and installed inaccordance with BS7671 ofthe Wiring Regulations.

2 6N 4

Time switch16A MCB

N

L

To heaterN

L

Fig. 23 CPT11


Control and Command - audible services 1Many domestic bells are battery operated but in a commercial situation this is not practical nor economic.

It is preferable to operate bellcircuits as separated extra-low voltage circuits where thecircuit is isolated from earth insuch a way that a single faultcannot give rise to a risk ofelectric shock. The voltagesource is derived from asafety transformer complyingwith BS3535 and having asecondary voltage of 8V.

The transformer may bemounted in the consumer unitboard or in an individualenclosure along with theaudible device.

L

N

240v 8v

Bell

Bell Pushes

TransformerMCB

Fig. 24

32 Sec1

Control and Command - performance figures


1Analogue time switchesDescription 24 hour programmable timer

Time base Quartz

Time accuracy One second per day, not accumulative

Programming Mechanical sliders, minimum interval 15 minutes

Maximum 48 switchings per day

Manual control 3 position switch under front cover: ON Automatic OFF

Motor supply 230V +/- 10% 5060Hz Load 2VA

Back up 100 hour capacitor type battery

Contact 1 changeover, rated 250V 5060 Hz 16A resistive. 4A at 0.6 pf

Operating temp. -10C to +50C

Terminals Tunnel type, up to 6mm2

Cover Clear plastic, sealable

Mounting On symmetrical DIN rail in LoadCentre KQ boards, Qwikline II units or individual

enclosures

Dimensions mm Width 18 (1 module)

Height 90

Depth 66

L

N

1

2

1

2

3

4

(L) Live

(N) Neutral

Off

P

N

1

2

Table 13

CTS24

CTS24


Control and Command - performance figures 1

L 1 3 5

(L) Live

(N) Neutral

N 2 4 6

L 1 3 5

1 2 3 4 5 6 7

N 2 4 6

auto

off31 03 01

11:02

Digital time switchesDescription 7 day programmable digital time switch

Time base Quartz

Time accuracy One second per day, not accumulative

Display Time, day, date, contact status and mode

Programming Multi lingual menu driven programming

Languages English, French, Italian, Spanish, Portuguese or German

Manual control Override, temporary or permanent

Min. switch time One minute

Switching operations 1 channel: 28, 2 channel: 42

Summer/winter Manual or automatic control for UK, Europe or USA

Cover Clear plastic, sealable

Motor supply 230V +/- 10% 50-60Hz Load 6VA

Back up Battery: 1 channel 3 years, 2 channel 5 years

Contacts 1 changeover, rated 250V 50-60 Hz 16A resistive. 10A at 0.6 pfMotor load: 2300 VA


Mounting On symmetrical DIN rail in LoadCentre KQ boards, Qwikline II units or individual enclosures

Terminals Tunnel type, up to 6mm2

Dimensions mm Width 45 (2.5 module)Height 90Depth 66

Table 14

CPT11

34 Sec1



1Presence detectorDescription Infra red sensor for lighting control

Lighting is switched if persons are detected and the lighting level is belowthe pre set threshold

Location Ceiling mounted 2.5 to 3 m above floor level

Supply 230V 50Hz

Detection zone 360C horizontally 180C vertically

Contact rating 2000W incandescent lamps,1000W LV halogen lamps1000VA fluorescent tubes with standard control gear16x(1x36W), 12x(2x36), 12x(1x58W) or 8x(2x58W) fluorescents with electronic control gearFor higher ratings use contactor to switch the load

Maximum reach High resolution close range 4m dia, safe distance range 24m dia

Switching threshold 20 1300 lux

Switch off delay 4 15 minutes adjustable

Enclosure IP20


A

12m 2m 1m 0 1m

1m

2m 12m

Close range (radius of 2m)

B

Distant range (radius of 12m)

A: SensorB: Sitting position

Table 15

CPD360


Control and Command - performance figures 1PIR detectorDescription Passive infra red detector for sensing movement within the specified

detection zone. A built in cell ensures that the lighting is only switched when the ambient light level is below that set on the device.

Function For switching security or safety lighting

Detection zone 12 metres and 180C. The angular range may be reduced by using the shroud supplied.

Ambient light level Adjustable 3 80 lux

Switch off delay After movement detection the contacts stay closed for an adjustable timeperiod of 4 seconds to 15 minutes.

Contact rating 250V ac 10A resistive , 6A at 0.6 pf*, halogen lamps 500w, incandescent 1000W

Supply 230V +/- 10% 50Hz


Protection IP54

Mounting Wall mounted positioned to cover the area to be secured

Room thermostatDescription Room thermostat

Function Simple room thermostat for the control of room heating

Mounting Wall mounting onto flat vertical surface

Temperature range +5C to +30C

Differential 0.5K

Range limitation The setting range can be restricted by using adjusting rings inside the adjustment dial

Supply 230V +/-10% 50Hz

Contact Normally closed contact, opens on rising temperature

Contact rating 10A resistive, 4A at 0.6 pf

Protection IP40

Terminals Tunnel terminals accept up to 2.5mm2

Table 16

Table 17

* Incandescent 1000W, Halogen 500W Fluorescent lamps must be switched via a relay.

CPIR

CRT1

36 Sec1



1Audible alarmsDescription Audible alarmsSupply 8V ac for use with SQD bell transformer reference CBX8Load 3.6VASound level 70dBMounting On symmetrical DIN rail in LoadCentre KQ boards, Qwikline II units or individual

enclosuresTerminals Tunnel terminals for cables up to 4mm2Dimensions mm Width 18 (1 module)

Height 82Depth 63

Bell transformerDescription Double insulated bell transformerStandards Designed and tested to BS3535 Pt 1, BSEN 60742, BSEN 61558Supply Primary 240V 50Hz

Secondary 8V 8VAMounting On symmetrical DIN rail in LoadCentre KQ boards, Qwikline II units or individual

enclosuresTerminals Tunnel terminals for cables up to 4mm2Dimensions mm Width 36 (2 modules)

Height 80Depth 74

230Vac

8Vac

CBX8 Transformer

8Vac

CBZ8 Buzzer

8Vac

CBL8 Bell

(L) Live

(N) Neutral

Push button

230Vac

8Vac

8Vac

8Vac

Table 18

Table 19

CBZ8, CBL8 & CBX8


Control and Command - performance figures 1Light sensitive switchDescription Light sensitive switchFunction Monitors the ambient light level to switch on lighting when this falls below

the preset threshold. Sensor The switch is supplied with a photo cell for remote mountingLight levels 2 ranges are selectable: 2 35 lux or 35 - 2000 luxTime delay 80 seconds to prevent inadvertent operation due to sudden light level changesStatus LED indicator on front face of switchSupply 220 / 240 V 50HzBurden 2.2VAContact 1 changeover, rated 250V 10A resistive, 1100W lighting,

For larger loads use a suitable contactor to switch the loadTerminal capacity Main terminals 0.5 6mm2, control terminals 0.5 2.5mm2


Dimensions mm Width 63 (3.5 modules)Height 81Depth 65

L 3 5

N 2 4 62 4 6off

Lamp supply Lamp

on

(L) Live

Photo Cell

(N) Neutral

Photo Cell

35 to 2000 lux2 to 35 lux

L

N

3 5

Brightness adjustment

Brightness adjustment

5 lux - Night

20 lux

35 lux

200 lux

1000 lux

2000 lux

Table 20 * For fluorescent and halogen lamps a relay must be used.

CLS110

38 Sec1



1

Time delay ON relayDescription Time delay ON relay. After coil energisation the contacts close at the end

of the set time delay. Function Use to delay the switching of a circuit. In large lighting schemes they can

be used to stagger the lighting switchon to limit the inrush current.Time range 0.1 seconds to 10 hours in 7 ranges. Accuracy +/- 10% of full scaleAdjustment 2 adjustment knobs on the front face, under a transparent sealable coverIndication Green indicator on front face. Flashes during timing periodContact 1 changeover contact Contact rating 250V ac. 8A resistive, 3A at 0.6 pfSupply 220 / 240 V 50Hz, 24Vdc 10%Mounting On symmetrical DIN rail in LoadCentre KQ boards, Qwikline II units or individual

enclosuresTerminals Tunnel type, 0.5 6mm2 or 2x2.5mm2Dimensions mm Width 18 (1 module)

Height 81Depth 60

1

A1

A2

5

4

2

6

1 A1

(L) Live

Switch

(N) Neutral

A2

5

2 4 6

250v 50Hz

Control MCB Load MCB

CS

Load

Switch

A1

N

15

18 16 A2

Load

tT

ControlSwitch

Table 22

CCR110

Control relayDescription Control relayFunction General purpose relay for control circuit uses.Contacts One changeover contact and one normally open contact, rated 250V ac

10A resistive.Manual control The relay has a pushbutton on the front for testing purposes which also

acts as an indicator, showing red when the coil is energised.Supply 230 / 240 V 50 HzConsumption 4VA inrush and holdMounting On symmetrical DIN rail in LoadCentre KQ boards, Qwikline II units or individual

enclosuresTerminals Main Tunnel type, 0.5 6mm2

Coil Tunnel type, 0.5 2.5mm2Dimensions mm Width 18 (1 module)

Height 81Depth 69

Table 21

CTR1


Control and Command - performance figures 1Control Time delay OFF relayDescription Time delay relay, relay de-energises after preset time, adjustable

1 7 minutes

Function Relay is intended for use in lighting circuits. On energisation of the relay the lighting is switched on. After the preset time period the lighting is switched off. This ensures that lighting is not left on unnecessarily and so is ideal for areas such as hallways, stairways etc where persons are not continually present. The relay may also be used to control a ventilation fan so that it runs on after the lights have been switched off (option 1).

Time range 1 to 7 minutes in 15 second steps

Manual control Override switch on front face allows lighting to be switched on permanently

Contact 1 normally open contact

Note The switch on the side of the device must be in position 4 if the control switches are placed in the live side (normal practice)

Contact rating 250V ac. 16A resistive, 2000W maximum lighting load, Incandescent only, 540W fluorescent

Supply 220 / 240 V 50Hz

Consumption 200VA inrush, 1.1VA hold


Terminals Main Tunnel type, 0.5 6mm2

Coil Tunnel type, 0.5 2.5mm2

Dimensions mm Width 18 (1 module)Height 87Depth 70

3

N

P

4

(L) Live

Switch

(N) Neutral Lamp Fan

3P

4N

M

(L) Live

Push Button

(N) NeutralDelay off Timer setting

Time

Option 2

Delay off Timer setting

Lamp Load

Push Button

Option 1

Fan Load

Lamp Load

Switch

Lamp

3P

4N

Table 23

CDT116

40 Sec1

Specification for consumer units


11.1 All MCB consumer units

shall be manufacturedto BSEN60439 parts 1and 3 and shall havebeen subjected to a16kA (CM16) throughfault.

1.2 All MCB consumer unitsshall incorporate a fullyshrouded main busbarassembly, which shallprovide protection byinsulating barriers to aminimum of IP2X (asdefined in BSEN60529),with the front coverremoved. The removalof any incoming oroutgoing device shallnot reduce the level ofprotection provided.

1.3 Busbar insulatingbarriers shall be factoryfitted, permanently fixedand non-removable. Itshould not benecessary to removeany part of theinsulating barriers toconnect any incomingor outgoing device aslisted in items 2.1 and2.2.

1.4 Busbar insulatingbarriers shall beconstructed so as toremain unaffected byremoval of circuitprotection devices andsystem changes, i.e.IP2X must bemaintained at all timesin all ways, populatedor spare. It shall not benecessary to fitinsulating boots or otherremovable accessoriesto achieve and maintainthe IP2X status on thebusbar-insulatingbarrier.

1.5 Where spare outgoingways are available, itshall be possible tomount any DIN controlproduct in thoseoutgoing ways withoutmodification of theassembly.

1.6 All MCB consumer unitsshall be IP30 with coverfitted.

1.7 Consumer unitenclosures may bemanufactured fromsheet steel or be of allinsulated construction.

1.8 To allow for allinstallation requirementsto be met, and forconsistent levels ofbusbar insulationthroughout, themanufacturer shallprovide a completerange of consumer unitsincluding:- Standard,Dual supply, Multi tariff,Split load.

1.9 Provision shall be madefor flush mounting ofmetal enclosureconsumer units.

1.10 Metal enclosures shallinclude cable entryknockouts suitable fordouble insulated cablesor conduit entry.Insulated enclosuresshall incorporate pre-formed cable entrypoints.

1.11 All MCB consumer unitsshall include numberedlabelling to allconnection pointsincluding earth andneutral terminals.

1.12 To allow fasterinstallation andguarantee connectionintegrity, all incomingand outgoing devicesintended for protectionor isolation will be ofthe plug on type.

1.13 Earth bars will allow forbonding connections.

1.14 All consumer units mustbe able to accept onthe outgoing side amixture of MCBs,RCBOs and RCCBswith control andcommand deviceswithout anymodification to the unit.

Specification for consumer units.


Specification for devices to be used in consumer units 12.1 The following incoming

devices will be availablefor use in both insulatedand metal cladconsumer units.RCCBs may be usedas a main incomer or inthe intermediaryposition in a split loadunit.

100A switchdisconnection to BSEN60947-3.

100A terminal block.

100A - 30mA, 100mAor 100mATD or 300mARCCB to BSEN 61008.

63A - 30mA or 100mARCCB to BSEN 61008.

2.2 In order to providegreater on site flexibility,as standard allconsumer units will beavailable withoutincoming devices fitted.On request, theconsumer unitmanufacturer shall beable to supplyconsumer units fittedwith both incoming andoutgoing devices. Themanufacturer shall alsobe able to pre-wireinternal control circuitswhere applicable.

2.3 To allow for allinstallation circuitprotection requirementsto be met, and makeprovision for futuresystems upgrades, allconsumer Units willaccept the followingoutgoing devices in anymix or combination:-

Miniature circuitbreakers (MCBs)having the followingcharacteristics:

Plug on connectiontype.

B or C curve.

Manufactured andtested to BSEN60898,and BSEN60947-2.

Have an energy letthrough level class 3.

RCBOs having thefollowingcharacteristics:

Manufactured andtested to BSEN61009.

A breaking capacity of6kA to BSEN60898.

B curve.

Permanent nonadjustable and nonremovable earth faultprotection.

A width of no more thanone outgoing way.

Automatic protectionagainst reverse polarity.

Automaticdisconnection of the livecircuit in the event of alost neutral.

Plug-on connectiontype have a let throughenergy level Class 3.

2.4 For the purpose ofenergy managementand control and energymanagement, theconsumer unitmanufacturer shall beable to supply thefollowing productsloose or pre-wiredwithin the consumerunit.

Contactors from 25A to63A.

Impulse relays.

Single and dual channeltime switches.

ELV transformer andcompatible bell/buzzer.

Specification for devices to be used in consumer units.

42 Sec1

A type single phase distribution boards


1LoadCentre KQ a range overview. A type distribution boards have a higher performance level than consumerunits, incoming devices up to 125A with outgoing LoadCentre KQ MCBs at 10kA.

Standard

For small commercialapplications.

Metal - from 2 to 24outgoing ways

Split load

For small commercialapplications requiring partialRCD protection.

Metal - a range of splitswith up to 12 outgoingways

Specialised

For specific applications

Higher IP rating

A range of colours

Multi tariff units

A type standard A type split load


A type single phase distribution boards 1Incoming devices

For incoming isolation, controland protection.

Switch disconnector -125A

Terminal block - 125A fordirect cable connection

RCCBs - 63A or 100A,with sensitivities of 30, 100or 300mA

Miniature circuitbreakers (MCBs)

For outgoing isolation, controland protection.

B, C or D curve

3 to 63A current ratings

10kA rated to BS EN60898

15kA rated to BS EN 60947-2

Residual current circuitbreakers withovercurrent protection(RCBOs)

For outgoing isolation, controland protection.

Only 1 single pole waywide

6 to 45A current ratings

30mA

C curve

Surge protection controldevices

The same products are usedin an A type board as areused in the consumer unit.

Protection is via a 20A 10kALoadCentre KQ MCB.

Control and command

For automated control of arange of electrical loads.

Contactors up to 40Asingle phase

Bell transformer andcompatible bells/buzzers

Light sensitive switches

44 Sec1

A type single phase distribution boards


1LoadCentre KQ - a step by step guide to the benefits as you install, A type single phase or B type three phase.

Step 1

loadCentre KQ is suppliedwithout devices as standard,offering the flexibility tochoose from distributors shelfwhat incomers to fit.Alternatively we can assembleand pre-wire the unit ifrequired.

Step 2

KQs unique fixing systemprovides a common platformfor both devices and controldevices. This means noadaptation or separate wallspace is required for itemssuch as bell transformers ortime switches for gardenlighting.

Step 3

The unique fully encapsulatedbusbar system provides muchhigher levels of protectionagainst direct contact with liveparts during testing.

Step 4

All devices plug on soconnections are guaranteedand installation time isconsiderably reduced.


Specification for LoadCentre KQ distribution boards 11.1 All MCB single phase

distribution boards shallbe manufactured to BSEN60439 parts 1 and3 and shall have beensubjected to a 16kA(CM16) through fault.

1.2 All MCB distributionboards shall incorporatea fully shrouded mainbusbar assembly, whichshall provide protectionby insulating barriers toa minimum of IP2X (asdefined in BSEN60529),with the front coverremoved. The removalof any incoming oroutgoing device shallnot reduce the level ofprotection provided.

1.3 Busbar insulatingbarriers shall be factoryfitted, permanently fixedand non-removable. Itshould not benecessary to removeany part of theinsulating barriers toconnect any incomingor outgoing device aslisted in items 2.1 and2.2.

1.4 Busbar insulatingbarriers shall beconstructed so as toremain unaffected byremoval of circuitprotection devices andsystem changes, i.e.IP2X must bemaintained at all timesin all ways, populatedor spare. It shall not benecessary to fitinsulating boots or otherremovable accessoriesto achieve and maintainthe IP2X status on thebusbar-insulatingbarrier.

1.5 Where spare outgoingways are available, itshall be possible tomount any DIN controlproduct in thoseoutgoing ways withoutmodification of theassembly.

1.6 All MCB distributionboards shall be IP30with cover fitted.

1.7 Distribution boardenclosures may bemanufactured fromsheet steel.

1.8 To allow for allinstallation requirementsto be met, and forconsistent levels ofbusbar insulationthroughout, themanufacturer shallprovide a completerange of distributionboards including:-Standard, Dual supply.

1.9 Provision shall be madefor flush mounting ofmetal enclosure.

1.10 Metal enclosures shallinclude cable entryknockouts suitable fordouble insulated cablesor conduit entry.Insulated enclosuresshall incorporate pre-formed cable entrypoints.

1.11 All MCB distribution

boards shall includenumbered labelling to all connection pointsincluding earth andneutral terminals.

1.12 To allow fasterinstallation andguarantee connectionintegrity, all outgoingdevices intended forprotection or isolationwill be of the plug ontype.

1.13 Earth bars will allow forbonding connections.

1.14 All distribution boardsmust be able to accepton the outgoing side amixture of MCBs,RCBOs and RCCBswith control andcommand deviceswithout anymodification to the unit.

Specification for LoadCentre KQ distribution boards.

46 Sec1

Specification for devices to be used in LoadCentre KQ distribution boards


12.1 The following incoming

devices will be availablefor use. RCCBs may beused as a main incomeror in the intermediaryposition in a split loadunit.

125/250A SwitchDisconnection to BS EN 60947-3.

125A terminal block.

100A - 30mA, 100mAor 100mATD or 300mARCCB to BSEN 61008.

63A - 30mA or 100mARCCB to BSEN 61008.

2.2 In order to providegreater on site flexibility,as standard alldistribution boards willbe available withoutincoming devices fitted.On request, thedistribution boardmanufacturer shall beable to supply unitsfitted with bothincoming and outgoingdevices. Themanufacturer shall alsobe able to pre-wireinternal control circuitswhere applicable.

2.3 To allow for allinstallation circuitprotection requirementsto be met, and makeprovision for futuresystems upgrades, alldistribution boards willaccept the followingoutgoing devices in anymix or combination:-

Miniature circuitbreakers (MCBs) havingthe followingcharacteristics:

Plug on connectiontype.

B, C or D curve.

Manufactured andtested to BSEN60898,and BSEN60947-2.

Have an energy letthrough level class 3.

RCBOs having thefollowingcharacteristics:

Manufactured andtested to BSEN61009.

A breaking capacity of10kA to BSEN60898.

C curve.

Permanent nonadjustable and nonremovable earth faultprotection.

A width of no more thanone outgoing way.

Automatic protectionagainst reverse polarity.

Automaticdisconnection of the livecircuit in the event of alost neutral.

Plug-on connectiontype have a let throughenergy level Class 3.

2.4 For the purpose ofenergy managementand control and energymanagement, thedistribution boardmanufacturer shall beable to supply thefollowing productsloose or pre-wiredwithin the consumerunit.

Contactors from 25A to100A.

Impulse relays.

Single and dual channeltime switches.

ELV transformer andcompatible bell/buzzer.

Specification for devices to be used in LoadCentre KQ distribution boards.

Sec2 1

Commercial and industrial solutions for 3 phase distribution 2

introduction

Section 2

section 2

Contents

When designing a three phase system for commercial or industrial use different criteria has to betaken into consideration; this section leads the designer through from transformer to final loadprotection. It describes the type of protection required at different levels within the system and theway in which the protection devices operate.

Discrimination is preferred within this type of system as the loss of supply to a part of the buildingcan have serious consequences; the guide will lead the designer through choice of device andincludes tabulated information on which device to use. Cascading is also explained in this section,which can lead to reduced costs while maintaining the performance of the system.Information on motor control and protection are also detailed within this section.

The requirements of electrical power distribution

Earthing systems

MV/LV transformers and selection of devices

Determination of short circuit current

Discrimination using circuit breakers

Discrimination using residual current devices

Energy let through levels and cables sizes

Cascading using circuit breakers

Moulded case circuit breaker performance figures

Miniature circuit breakers for industrial applications

Surge protection

Protection of motor circuits

Busbar trunking

Health

Public building & Public housing

Emergency services

Leisure services

Education

2 Sec2

Benefit of Square Ds expertise

Commercial and industrial solutions for 3 phase distribution

2Established in the UK in 1955,Square D has developed anexpertise which ensures it iswell positioned to serve thepublic sector buildings marketwith cost effective solutions inelectrical distribution,protection and control.

With this expertise brings awealth of experiencerepresented by Square Dsinvolvement in a broadspectrum of public sectorbuilding projects includingthose related to the sectorsof:

Cost effectiveness

To ensure best value isattained from capital andoperational investment ofpublic funds.

Safety

To ensure the highest level ofprotection is afforded topublic building stock and thepeople who use them.

Quality

To meet expectationsregarding reliability andservice life of installedequipment.

Continuity

To ensure the integrity ofelectrical networks guaranteethe continuous operation ofcritical installations.

Flexibility

To help accommodate thechanges of use and themodifications that publicbuildings may require.

Sec2 3Commercial and industrial solutions for 3 phase distribution

The requirements of electrical power distribution 2The design of LV installations leads to protection devices being fitted for four types of faults:

Overloads

Short circuits

Insulation faults

Overvoltages

Safety and availability of energyare the operators primerequirements.

Coordination of protectiondevices ensures these needs aremet at optimised cost.

Operation of these protectiondevices must allow for:

The statutory aspects,particularly relating tosafety of people

Technical and economicrequirements

The chosen protection must:

Withstand and eliminatefaults at optimised costwith respect to thenecessary performance

Limit the effect of a fault tothe smallest part possibleof the installation in orderto ensure continuity ofsupply

Achievement of theseobjectives requirescoordination of protectiondevice performance,necessary for:

Managing safety andincreasing durability of theinstallation by limitingstresses

Managing availability soeliminating the fault bymeans of the protectiondevices immediatelyupstream

The circuit breakercoordination means are:

Cascading

Discrimination

If the insulation fault isspecifically dealt with by earthfault protection devices,discrimination of the residualcurrent devices (RCD's) mustalso be guaranteed.

Overvoltage protection

Risk assessment of the siteand equipment will definethe level of surgeprotection required to dealwith overvoltages. Highrisk areas must alsorespect initialdiscrimination

4 Sec2



2Structure of LV electrical power distribution

1000 kVA

1000 A

M M

100 A400 A

100 A 160 A

75 kW

16 A

20 kV/400 V1000 kVA

1600 A

15 kA

20 kA

40 kA

23 kA45 kA

Mainswitchboard

Building utilities

Lighting, heating, etc.

Distributionboard

Sub-distributionswitchboard

Power distributionswitchboard -industrial/commercial

Non-priorityfeeders

Priority feeders

Distribution

Distributionenclosure

Distributionworkshop 1

The various levels of an LVelectrical installation

Each of the three levels of theinstallation has specificavailability and safety needs.

Simplified diagram of a standard installation covering most of the cases observed in practice.

Protection devices and theircoordination must be suited tothe specific features of theinstallation.

At the main switchboard, theneed for energy availability isgreatest

At the sub-distributionswitchboards, limitation ofstresses in event of a fault isimportant

At final distribution, operationof the device in the shortesttime relative to the type offault

Fig. 25


The requirements of electrical power distribution 2Circuit breaker functions

This connection device is ableto close and break a circuitregardless of current up to itsbreaking capacity.

The functions to beperformed are:

Close the circuit

Conduct current

Open the circuit and breakthe current

Guarantee isolation

The requirements concerninginstallation, cost optimisation,management of availabilityand safety generate differingtechnological choicesconcerning the circuit breaker.

Main data of thesecircuit breakers

Of industrial type, meetingstandard BS EN 60947-2

With a high ultimatebreaking capacity (lcu)from 65 to 150 kA

With a nominal rating of1000 to more than 5000 A

Category B to BS EN60947-2:

With a high withstandvalue from 65 kA to 100 kA- 1 s

With a high electrodynamicwithstand (EDW)

With a stored energyoperating mechanismallowing quick changeoverto standby supplies

Level A: the mainswitchboard

This unit is the key to theentire electrical powerdistribution: availability ofsupply is essential in this partof the installation.

Short circuit currents arehigh due to:

The close proximity of theHV/LV transformer

Large sized busbars forconveying high currents

This is the area of the powercircuit breakers

These circuit breakers aredesigned for high currentelectrical distribution:

They are normally installedin the main switchboard toprotect high currentincomers and feeders

They must remain closed inevent of short circuits soas to let the downstreamcircuit breaker eliminatethe faults. Their operationis normally time-delayed

ElectroDynamic Withstand(EDW) and high thermalwithstand characterised by ashort time withstand current(lcw) are essential i.e. 65kA/1 sec.

Continuity of supply isensured by totaldiscrimination:

Upstream with theprotection fuses or circuitbreakers of the HV/LVtransformer (*)

Downstream with all thefeeders (timediscrimination)

(*) The benefit of HV/LV discrimination

lies above all in the fact that

resumption of operation has fewer

constraints in LV (accessibility,

padlocking). This offers

considerable advantages for

continuity of supply.

6 Sec2



2These boards belong to theintermediate part of theinstallation:

Distribution is via correctlysized busbar trunking orcables

Sources are still relativelyclose: short circuit currentscan reach 100 kA

The need for continuity ofsupply is still very great

Protection devices mustconsequently limit stressesand be perfectly coordinatedwith upstream anddownstream LV distribution.

Main data of the mouldedcase circuit breakers:

Of industrial type, meetingstandard BS EN 60947-2

With a high breakingcapacity (25 to 50 kA)

With a nominal rating from100 A to 1600 A

Category B for high ratingcircuit breakers (> 630 A)

Category A for lower ratingcircuit breakers (< 630 A)

With fast closing andopening and with threeoperating positions(ON/OFF/Tripped)

This is the area of themoulded case circuitbreakers

These circuit breakers mustopen and break the current asquickly as possible. The mainneed is to avoid as far aspossible stresses at cable andconnection level and even atload level. For this purpose,repulsion at contact level mustbe encouraged in order toeliminate the fault even as thecurrent is rising.

The repulsion effects can beenhanced by the inclusion ofmagnetic circuits on the maincontacts.

Continuity of supply isensured by discrimination:

Total for downstreamdistribution - priority feedersolutions

Partial, possibly, to supplynon-priority feeders

Level B: the sub distribution board


The requirements of electrical power distribution 2The protection devices areplaced directly upstream ofthe loads: discrimination withthe higher level protectiondevices must be provided.

A lower level of short circuitcurrent characterises thislevel, due to the length ofcables in the system.

This is the area of theminiature circuit breaker

These circuit breakers aredesigned to protect finalloads. The purpose is to limitstresses on cables,connections and loads.

The technologies for theminiature circuit breakers,mainly used at this installationlevel, prevent such stressesfrom occurring.

In miniature circuit breakers,limitation partly depends onthe magnetic actuator. Oncethe mechanism has beenreleased, it will strike themoving contact making itmove at a high speed veryearly on. Arc voltage thusdevelops very quickly at avery early stage. For smallrating circuit breakers, specificpole impedance contributes tolimitation.

The miniature circuit breaker isideal for domestic use and forthe protection of auxiliaries; itthen conforms to standard BS EN 60898.

On the other hand, if it isinstalled for industrial use, itmust meet standard BS EN 60947-2.

Main data of these circuitbreakers:

A breaking capacity tomatch needs (i.e. Below 10kA on average)

A nominal rating of 1.5 to125 A according to theloads to be supplied

Intended for domesticapplications: must conformto standard BS EN 60898*

The protection devicesinstalled must provide:

Current limitation

Operating convenience

Absolute safety

Disconnectors

(*) If the MCBs are to be operated byunskilled users they must meet thedomestic or similar standard.

Level C: final distribution

8 Sec2



2Changes in user needs andtechnologies have led to amarked increase in standardsrequirements for industrialcircuit breakers. Conformitywith standard EN 60947-2 andBS EN 60947-2 can beconsidered as an all-riskinsurance for use of circuitbreakers. This standard hasbeen approved by allcountries.

The principles

Standard BS EN 60947-2 ispart of a series of standardsdefining the specifications forLV electrical switchgear:

The general rules BS EN 60947-1, that groupthe definitions,specifications and testscommon to all LV industrialswitchgear

The product standards BS EN 60947-2 to 7, thatdeal with specificationsand tests specific to theproduct concerned

Standard BS EN 60947-2applies to circuit breakers andtheir associated trip units.Circuit breaker operating datadepend on the trip units orrelays that control theiropening in specific conditions.

Standard BS EN 60947-2, circuit breakers for industrial use

This standard defines themain data of industrial circuitbreakers:

Their classification:utilisation category,suitability for isolation, etc

The electrical setting data

The information useful foroperation

The design measures

Coordination of protectiondevices

Fig. 26

Relevant British standards.

BS EN 60439-3

Specifications for low voltage switchgear and control gear assemblies.

Particular requirements for low voltage switchgear and control gearassemblies intended to be installed in places where unskilled persons haveaccess to their use - distribution boards.

BS EN 60898

Circuit breakers for overcurrent protection for household and similarinstallations. Circuit breakers for AC and DC operation.

BS EN 61009

Specification for residual current operated circuit breakers with integralovercurrent protection for household or similar uses (RCBOs). Applicability ofthe general rules to RCBOs functionally independent of line voltage.

BS EN 61008

Specification for residual current operated circuit breakers without integralovercurrent protection for households or similar uses (RCCBs). Applicabilityof the general rules to RCCBs functionality independent of line voltages.

BS EN 60439-1

Specification for low voltage switchgear and control gear assemblies typetested and partially type tested assemblies.

BS EN 60497-2

Specification for low voltage switchgear and control gear - circuit breakers.


The requirements of electrical power distribution 2Table of main data to BS EN 60947-1Voltage Ue Rated operational voltage data Ui Rated

sq d-elect aapp'n guide

Documents

single unit

distribution systemfor

use of control

downstream devices

upprotection devices

residential applications

thanresidual current

products asstandard