Bsi bs en 60439 3 1991 (2010)

Specification forLow-voltage switchgear and controlgear assemblies — Part 3: Particular requirements for low-voltage switchgear and controlgear assemblies intended to be installed in pl

Specification for

Low-voltage switchgear

and controlgear

assemblies —

Part 3: Particular requirements for

low-voltage switchgear and controlgear

assemblies intended to be installed in

places where unskilled persons have

access to their use — Distribution

boards

This British Standard is the UK implementation of

EN 60439-3:1991+A2:2001, incorporating corrigenda April 1994, December 2005 and November 2009 It was derived by CENELEC from IEC 60439-3:1990 incorporating amendments 1:1993 and 2:2001

It supersedes BS EN 60439-3:1991 which is withdrawn

The CENELEC common modifications have been implemented at the appropriate places in the text The start and finish of each common modification is indicated in the text by tags }~ Where a common modification has been introduced by amendment, the tags carry the number of the amendment For example, the common modifications introduced by CENELEC amendment A11 are indicated by hi

The start and finish of text introduced or altered by amendment is indicated in the text by tags !" Tags indicating changes to IEC text carry the number of the IEC amendment For example, text altered by IEC amendment 1 isindicated by !"

The UK participation in its preparation was entrusted by Technical Committee PEL/17, Switchgear, controlgear, and HV-LV co-ordination, to Subcommittee PEL/17/3, Low voltage switchgear and controlgear

assemblies

A list of organizations represented on this subcommittee can be obtained

on request to its secretary

The foreword and preface of IEC 439-3:1990 which do not form part of the text of EN 60439-3 have been quoted in National annex NA The deleted parts of the original IEC text are quoted in National annex NA

The foreword of the EN makes reference to “date of withdrawal (dow) of conflicting national standards” as “1994-12-01” In this case the relevant national standard is BS EN 60439-3 but the date of withdrawal relates only to those parts of the British Standard subject to amendment A1 Certificates and marks will not be awarded after this date with respect to the British Standard not incorporating amendment A1 They will be awarded only to the amended British Standard However, such certificates and marks already awarded with respect to the British Standard not incorporating amendment A1 may continue to apply for production until 1999-12-01

This publication does not purport to include all the necessary provisions of

a contract Users are responsible for its correct application

Compliance with a British Standard cannot confer immunity from legal obligations

This British Standard was

published under the authority

of the Standards Board and

comes into effect on

28 June 1991

© BSI 2010

Amendments/corrigenda issued since publication

Amd No Date Comments

8302 August 1994 Implementation of IEC amendment 1:1993

with CENELEC endorsement A1:1994

13466 1 May 2002 Implementation of IEC amendment 2:2001

with CENELEC endorsement A2:2001

UDC 621.316.54:621.3.027.2:620.1:614.8 Incorporating corrigenda April 1994

Descriptors: Low voltage switchgear, assemblies, unskilled persons

English versionLow-voltage switchgear and controlgear assemblies — Part 3: Particular requirements for low-voltage switchgear and controlgear assemblies intended to be installed in places where unskilled persons have access for their

use — Distribution boards

(IEC 60439-3:1990, modified)

Ensembles d’appareillage à basse tension —

Troisième partie: Régles particulières pour

ensembles d’appareillage BT destinés à être installés

en des lieux accessibles à des personnes non

qualifiées pendant leur utilisation —

Tableaux de répartition

(CEI 60439-3:1990, modifiée)

Niederspannung-Schaltgeräte-kombinationen —Teil 3: Besondere Anforderungen an

Niederspannung-Schaltgeräte-kombinationen, zu deren Bedienung Laien Zutritt haben

Installationsverteiler(IEC 60439-3:1990, modifiziert)

This European Standard was approved by CENELEC on 10 December 1990

CENELEC members are bound to comply with the CEN/CENELEC Internal

Regulations which stipulate the conditions for giving this European Standard

the status of a national standard without any alteration

Up-to-date lists and bibliographical references concerning such national

standards may be obtained on application to the Central Secretariat or to any

CENELEC member

This European Standard exists in three official versions (English, French,

German) A version in any other language made by translation under the

responsibility of a CENELEC member into its own language and notified to the

Central Secretariat has the same status as the official versions

CENELEC members are the national electrotechnical committees of Austria,

Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy,

Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and

United Kingdom

CENELEC

European Committee for Electrotechnical StandardizationComité Européen de Normalisation ElectrotechniqueEuropäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B-1050 Brussels

, December 2005 and November 2009

June 2001

© BSI 2010

2

Foreword

Following the decision taken by CENELEC

Technical Committee TC 17D at their Brussels

meeting in October 1989, the International

Standard IEC 60439-3:1990, together with the

common modifications prepared by CLC/TC 17D,

was submitted to the CENELEC Unique Acceptance

Procedure (UAP) in April 1990 for acceptance as a

European Standard

The text of the draft was approved by CENELEC as

EN 60439-3 on 10 December 1990

The following dates were fixed:

For products which have complied with the relevant

national standard before 1991-12-01, as shown by

the manufacturer or by a certification body, this

previous standard may continue to apply for

production until 1996-12-01

Endorsement notice

The text of the International Standard

IEC 439-3: 1990 was approved by CENELEC as a

European Standard with agreed common

modifications as given below

Common modifications

Foreword to amendment A1

The text of document 17D(CO)53, as prepared by Sub-Committee 17D: Low voltage switchgear and controlgear assemblies, of IEC Technical

Committee 17: Switchgear and controlgear, was submitted to the IEC-CENELEC parallel vote in September 1992

The reference document was approved by CENELEC as amendment A1 to EN 60439-3

on 8 December 1993

The following dates were fixed:

For products which have complied with

EN 60439-3:1991 before 1994-12-01, as shown by the manufacturer or by a certification body, this previous standard may continue to apply for production until 1999-12-01

7.6.1 Replace the text by:

Fuses for outgoing circuits shall

comply with the general requirements

of IEC 60269-3 or with a relevant

national standard where it is an

established practice for such use

— latest date of publication of

— latest date by which the national standards conflicting with the amendment have to be

4 Electrical characteristics of assemblies 5

5 Information to be given regarding

Table 7 — List of type tests to be performed 9

Table 7b — List of routine tests to be performed 10

Table 13 — Tightening torques for the

17Table 102 — Requirements for final circuit

protective devices: Semi-enclosed fuses

complying with BS 3036 and cartridge fuses

Table 103 — Cross sections of copper

conductors on load side of protective device

Figure 1 — Ball pressure test apparatus 13

Figure 101 — Test circuit to prove

Table 101 — Requirements for final circuit

protective devices: Circuit-breakers complying

with BS EN 60898 and RCBOs complying with

BS EN 61009

4 © BSI 2010

1 General

1.1 Scope

Replace the second note by:

This standard gives supplementary requirements for such enclosed distribution boards (DBU), which are stationary, type tested assemblies (TTA) for indoor use, containing protective devices and intended for use either in domestic (household) applications or in other places where unskilled persons have access for their use Control and/or signalling devices may also be included They are for use on a.c., with a nominal voltage

to earth not exceeding 300 V The outgoing circuits contain short-circuit protective devices, each having a rated current not exceeding 125 A with a total incoming load current not exceeding 250 A

NOTE The nominal voltage to earth in an IT system is taken as the nominal voltage of the system.

Unskilled persons normally have access to these assemblies, e.g for switching operations and for replacing fuse-links

of isolation may be included in the board or may be provided separately

2.2 Definitions concerning constructional units of assemblies

parts for aesthetic purposes

parts which are provided only to improve the appearance of an assembly and are not intended to give any electrical or mechanical protection

2.5 Definitions concerning the conditions of installation of assemblies

— the conditions of installation with respect to mobility (see 2.5.3 and 2.5.4);

#— the form of internal separation (see 7.7);

— the types of electrical connections of functional units (see 7.11).$

4 Electrical characteristics of assemblies

4.2 Rated current (of a circuit of an assembly)

Renumber existing 4.2 to read 4.2.1.

Add a new sub-clause:

4.2.2 Rated current of a distribution board

The rated current of a distribution board is that stated by the manufacturer as the rated current of the incoming circuit or circuits If there is more than one incoming circuit the rated current of a distribution board is the arithmetic sum of the rated currents of all incoming circuits that are intended to be used simultaneously This current or currents shall be carried without the temperature rise of the several parts

exceeding the limits specified in 7.3 when tested according to 8.2.1.

# 4.7 $ Rated diversity factor

Replace the note and Table 1 by the following:

For the purpose of this standard the number of main circuits is the number of outgoing circuits connected

to each supply phase In the absence of information concerning the actual currents, the conventional values given in Table 1 may be used

6 © BSI 2010

5 Information to be given regarding the assembly

5.1 Nameplates

Add as second sentence:

The nameplates may be mounted behind a door or removable cover

In c) replace 60439-1 by 60439-3.

Replace the text of l) by:

l) degree of protection (see 7.4.2.2.1), if greater than IP2XC according to IEC 60529;

#Add after item l)

r) Not applicable.

s) Not applicable.

u) rated current of distribution board The rated current of the distribution board shall be marked on the

ASSEMBLY or the nameplate.$

Replace the last paragraph by:

“Standard pollution degree for an ASSEMBLY to IEC 60439-3:

ASSEMBLIES to this standard are generally for use in a pollution degree 2 environment Other pollution degrees may apply, depending upon particular applications or the mirco-environment

NOTE The pollution degree of the micro-environment may be influenced by installation in an enclosure.”

6.2.9 Delete the examples.

Add:

For flush-type assemblies recessing into a wall is not considered to be a special condition

7 Design and construction

7.1.1 General

Add the following at the beginning of the first paragraph:

Assemblies intended for use by unskilled persons shall be designed as type-tested LV switchgear and controlgear assemblies (TTA)

Add at the end of the first paragraph:

For parts of distribution boards which are made of insulating materials the resistance to heat shall be

verified according to #8.2.12$ The resistance of insulating materials to abnormal heat and to fire due

to internal electric effects shall be verified according to #8.2.13$.

Add a second sentence to the second paragraph:

Ferrous structural parts of distribution boards, including enclosures, shall have adequate resistance to

rusting when tested in accordance with #8.2.11$.

Text deleted

Text deleted

Add a second sentence and note to the third paragraph:

Enclosures of distribution boards shall, in addition, withstand an impact strength test in accordance

with #8.2.10$.

NOTE Parts for aesthetic purposes and individual components need not be subjected to the impact tests.

Add to the end of the clause:

Any cover which has to be removed during installation or maintenance shall not be used to support components to which conductors are connected if such conductors are subject to any stress when the cover

is removed In this case, a hinged door shall be used instead

Doors and the like provided with hinges shall allow free access and ease of operation of built-in components

as their respective phase conductor terminals

Terminals shall also be provided for the protective conductors of the incoming and outgoing circuits, which shall be similarly located or identified, and for any bonding conductors that may be required (e.g as appropriate to the system)

7.2.1.1 Delete reference to IP00.

#7.2.1.2 Replace IP2X by IP2XC.

7.2.1.3 Not applicable.

7.2.1.6 Not applicable.$

7.4.2 Add after the title:

NOTE Open type assemblies are not covered by this Part 3.

Delete the second paragraph.

7.4.2.2.1 Replace first sentence by:

All !accessible" surfaces shall provide a degree of protection of at least IP2XC according to IEC 60529

a) Removal or opening shall necessitate the use of a key or a tool

Where any parts inside the ASSEMBLY need occasional handling (such as replacement of a lamp or a fuse-link), an obstacle shall be provided so as to prevent persons from coming unintentionally into contact with live parts not protected by another protective measure However, this obstacle need not prevent persons from coming intentionally into contact by bypassing this obstacle with the hand It shall not be possible to remove the obstacle, except through the use of a key or tool.$

8 © BSI 20

Live parts, the voltage of which fulfills the condition for SELV (safety extra-low voltage), need not be covered

Add:

7.4.2.2.3 c) and 7.4.2.2.3 d) are not applicable.

7.4.3.2.2 Protection by total insulation

Replace the existing text of 7.4.3.2.2 d) by the following new text:

7.4.3.2.2 d) Delete in the first paragraph the words “The enclosure shall give at least the degree of

protection of IP3XD*.” and the corresponding footnote.$

7.4.5 Operating and maintenance gangways within assemblies

Not applicable

7.5.2.3 Not applicable.

7.6.1 Selection of components

Add at the end of the first paragraph:

ŽFuses for outgoing circuits shall comply with the general requirements of IEC 60269-3 or with the relevant national standards where it is an established practice for such use.

7.6.4 Replace title by: Removable parts.

Add at the beginning:

Withdrawable parts are not permitted in assemblies intended to be installed in places where unskilled persons have access for their use

7.7 Internal separation of assemblies by barriers or partitions

Add:

The barriers may be omitted if circuits at lower voltages are wired in cables insulated according to the phase-to-earth voltage of the main circuits

Safety extra-low voltage circuit conductors shall be in separate compartments, or separated from

conductors of circuits at different voltages by a metal screen or sheath connected to the protective

conductor, unless they are insulated for the highest voltage present, either individually, or collectively in multicore cables or other grouping of conductors

7.8.3.6 Not applicable.

10

#

a) Temperature rise limits 8.2.1 Verification of temperature rise limits 3a

Effective connection between

the exposed conductive parts

of the ASSEMBLY and the

protective circuit

8.2.4.1 Verification of the effective connection

between the exposed conductive parts of the ASSEMBLY and the protective circuit by inspection or by resistance measurementShort-circuit withstand

strength of the protective

circuit

8.2.4.2 Verification of short-circuit withstand

strength of the protective circuite) Clearances and creepage

a

h) Construction and marking 8.2.9 Verification of construction and marking 1a

j) Resistance to rusting and to

humidity 8.2.11 8.2.14 Verification of resistance to rusting and to humidity 4k) Resistance of insulating

materials to heat 8.2.12 Verification of resistance of insulating materials to heat 3l) Resistance of insulating

materials to abnormal heat

and to fire

8.2.13 Verification of resistance of insulating

materials to abnormal heat and fire due to internal electrical effects

5

m) Mechanical strength of

fastening means of enclosures 8.2.15 Verification of mechanical strength of fastening means of enclosures 2

a No failures by any samples.

10 © BSI 2010

!8.1.1 Type tests (see 8.2)

Type tests are intended to verify compliance with the requirements laid down in this standard for a given type of ASSEMBLY

Type tests shall be carried out on a sample of such an ASSEMBLY or on parts of ASSEMBLIES

manufactured to the same or similar design They shall be carried out on the initiative of the

manufacturers

The type tests are arranged in three separate sequences as detailed in Table 7a A sample selected for testing to a given sequence shall complete all the tests in that sequence in the order stated

Table 7a — Sequence of type tests

Table 7b — List of routine tests to be performed

# $ There shall be no failures by any samples during any of the tests a), c), d), e), g) or h) If the first sample submitted to a test sequence completes the sequence satisfactorily no further testing to that sequence is required If, however, a sample submitted to a test according to b), f), i), j), k), l) or m) fails,

#then the relevant test sequence shall be repeated on three additional$ samples and there shall be no failure."

#If modifications are made to components of the ASSEMBLY, new type tests have to be carried out only

in so far as such modifications are likely to adversely affect the results of these tests.$

Type tests include:

d) Verification of the continuity of the protective circuit 8.2.4

e) Verification of clearances and creepage distances 8.2.5

j) Verification of resistance to rusting and to humidity #8.2.11, 8.2.14$

k) Verification of resistance of insulating materials to

l) Verification of resistance to abnormal heat and to fire #8.2.13$

m) Verification of mechanical strength of fastening

Characteristics to be checked Subclauses Routine test according to 8.1.2

a) Wiring, electrical operation 8.3.1 Inspection of the assembly including inspection of

wiring and, if necessary, electrical operation test

c) Protective measures 8.3.3 Checking of protective measures and of the electrical

continuity of the protective circuits

Text deleted

8.1.2 Routine tests (see 8.3)

Replace b) by:

b) dielectric test (see 8.3.2);

A dielectric test is not required on distribution boards containing busbars and/or prefabricated main circuit wiring only, nor on simple constructions where an inspection under a) is sufficient

8.2.1.3 Temperature-rise test

Replace second paragraph by:

For this test the distribution board is loaded with its rated current (see 4.2) This current shall be

distributed amongst the smallest possible number of outgoing circuits so that each of these circuits is

loaded with its rated current multiplied by the rated diversity factor, as stated in #4.7$ If the exact

total load cannot be obtained by a number of devices loaded to this current, one circuit only may be loaded

to a lower value to give the correct total Fuses or miniature circuit-breakers shall be fitted as specified by the manufacturer and the power losses of fuse-links shall be stated in the report (Tests may be carried out using dummy fuse-links having the maximum power loss as specified in the relevant specification)

NOTE The appropriate diversity factor should be stated by the manufacturer in the type-test report.

#8.2.9 $ Verification of construction and marking

Compliance with Clause 5, 7.1.3, 7.4, 7.6, 7.7 and 7.8 shall be checked by inspection.

!# 8.2.10 $ Verification of impact strength

Compliance is checked on those exposed parts of the DBU which may be subjected to mechanical impact when mounted as in normal use

# 8.2.10.1 $ The test shall be carried out by means of a spring hammer test apparatus as described in

IEC 60068-2-63:1991, Test Eg: Impact, spring hammer The test is made after the sample has been for 2 h

at a temperature of –5 °C ± 1 K and each blow shall have an impact of 0,7 J

# 8.2.10.2 $ The sample with cover, or the enclosure, if any, shall be fixed as in normal use or placed

against a rigid support

Three blows shall be applied on separate places of each of the five accessible faces and door (if provided) They shall not be applied to knock-outs, built-in components complying with other standards, or other fastening means which are recessed below the surface so as not to be subject to impact

Cable entries which are not provided with knock-outs shall be left open If they are provided with

knock-outs, two of them shall be opened

Before applying the blows, fixing screws of bases, covers and the like shall be tightened with a torque equal

to that specified in Table 13."