IEC 61439-2 pdf download – Low-voltage switchgear and controlgear assemblies – Part 2: Power switchgear and controlgear assemblies

IEC 61439-2 pdf download – Low-voltage switchgear and controlgear assemblies – Part 2: Power switchgear and controlgear assemblies
8.4.3.2.2 Requirements for earth continuity providing protection against the
consequences of faults within the AsSEMBLY
Replacement of last paragraph:
When removable or withdrawable parts are equipped with a metal supporting surface,thesesurfaces shall be considered sufficient for ensuring earth continuity of protective circuitsprovided that the pressure exerted on them is sufficiently high. The continuity of the protectivecircuit of a withdrawable part shall remain effective from the connected position to the isolatedposition inclusively.
8.4.5.1 Devices to be operated or components to be replaced by ordinary personsThis subclause of Part 1 is not applicable.
8.4.5.2 Requirements related to accessibility in service by authorized personsAdditional subclause:
8.4.5.2.101 Operating and maintenance gangways within a PsC-ASSEMBLY
Operating and maintenance gangways (see 3.102.1 and 3.102.2) within an ASSEMBLY shallcomply with the requirements for basic protection as specified in IEC 61140. The design andconstruction of such gangways shall be agreed upon between ASSEMBLY Manufacturer and User.
Recesses within a PsC-ASSEMBLY of limited depth, in the order of 1 m, are not considered tobe gangways.
8.5.2 Removable parts
Replacement of the title:
8.5.2Removable and withdrawable partsAdditional subclauses:.
8.5.2.101General
The removable and withdrawable parts shall be so constructed that their electrical equipmentcan be safely isolated from or connected to the main circuit whilst this circuit is live. Theremovable and withdrawable parts may be provided with an insertion interlock (see 3.2.5 ofPart 1). Minimum clearances and creepage distances (see 8.3 of Part 1 and 8.3.2 above)shall be complied with in the different positions as well as during transfer from one position toanother.
NOTE lt may be necessary to ensure that these operations are not performed under load.8.5.2.102Removable parts
Removable parts shall have a connected position (see 3.2.3 of Part 1) and a removed position(see 3.2.4 of Part 1y.
8.5.2.103withdrawable parts
Withdrawable parts shall have in addition an isolated position (see 3.2.103) and may have atest position (see 3.2.102), or a test situation (see 3.1.102).They shall be distinctly located inthese positions.These positions shall be clearly discernible.
In Psc-ASSEMBLIEs with withdrawable parts all live parts shall be protected in such a mannerthat they cannot unintentionally be touched when the door,if any,is open and thewithdrawable part is withdrawn from the connected position or removed.Where an obstacle orshutter is used they shall meet the requirements of 8.4.5.2.5 of Part 1,and warning labelsshall be provided.
For the electrical conditions associated with the different positions of withdrawable parts, seeTable 103.
8.5.2.104 Interlocking and padlocking of withdrawable parts
Unless otherwise specified,withdrawable parts shall be fitted with a device，which ensuresthat the apparatus can only be withdrawn and/or re-inserted after its main circuit has beeninterrupted.
ln order to prevent unauthorized operation， withdrawable parts may be provided with meansfor a padlock or lock to secure them in one or more of their positions.
Addition:
8.5.101 Description of the types of electrical connections of functional units
The types of electrical connections of functional units within PSC-ASSEMBLIES or parts of psc-ASSEMBLIEs can be denoted by a three-letter code;
– the first letter denotes the type of electrical connection of the main incoming circuit;- the second letter denotes the type of electrical connection of the main outgoing circuit;- the third letter denotes the type of electrical connection of the auxiliary circuits.
The following letters shall be used:
– F for fixed connections (see 3.101.1);
– Dfor disconnectable connections (see 3.101.2);- w for withdrawable connections (see 3.101.3).Addition:
8.101lnternal separation of Psc-ASSEMBLIES
Typical arrangements of internal separation by barriers or partitions are described in Table104 and are classified as forms (for examples, see Annex AA).
The form of separation and higher degrees of protection shall be the subject of an agreementbetween ASSEMBLY Manufacturer and User.
PSC-ASSEMBLIEs can be divided to attain one or more of the following conditions betweenfunctional units,separate compartments or enclosed protected spaces:
protection against contact with hazardous parts. The degree of protection shall be at leastiP XXB;
protection against the passage of solid foreign bodies.The degree of protection shall be atieast lP 2×.
NOTE The degree of protection IP 2x covers the degree of protection lP XXB.
Separation may be achieved by means of partitions or barriers (metallic or non-metallic),insulation of live parts or the integral housing of a device e.g. a mouided case circuit breaker,
See 8.4.2.3 of Part 1 with regard to stability and durability of barriers and partitions.