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Insulated tails used to supply flats

Former Community Member over 5 years ago

We have a block of flats completed in 2017 that have supplies to individual flats in insulated twin and earth.

These cables are fed from a switch fuse and then into a ceiling disappearing into the building fabric.

I no longer carry electrical regs books (Approved sparks but fire specialist) but I did flag up the poor way these cables were installed and questioned if they required a RCD as they were not in metal conduit of armoured cables as I normally see.

Was it not a requirement in a 2015 amendment that all cables such as this were protected/RCD?

Many thanks for taking the time to read.

Paul.

Parents

0 mapj1 over 5 years ago

OK, I'm now near a copy of the 18th, and of course the actual thing is a bit wordy, so apologies for the block quote but '202 is clearly only for cables less than 50mm from surface, anything more than 50mm deep is out of scope and can be routed how you like -

however '203 which is for partition walls made with metal framework, sensibly does not have thick walls as a protection, as the wall will bring any voltage from a buried fault to the surface,and such partitions often have sharp metal edges internally that can snag a cable.

Hope this helps.

522.6.201 A cable installed under a floor or above a ceiling shall be run in such a position that it is not liable to

be damaged by contact with the floor or ceiling or their fixings.

A cable passing through a joist within a floor or ceiling construction or through a ceiling support (e.g. under

floorboards), shall:

(i) be installed at least 50 mm measured vertically from the top, or bottom as appropriate, of the joist or batten,or

(ii) comply with Regulation 522.6.204.

522.6.202 A cable installed in a wall or partition at a depth of less than 50 mm from a surface of the wall or partition shall:

(i) be installed in a zone within ISO mm from the top of the wall or partition or within ISO mm of an angle formed

by two adjoining walls or partitions. Where the cable is connected to a point, accessory or switchgear on any

surface of the wall or partition, the cable may be installed in a zone either horizontally or vertically, to the

point, accessory or switchgear. Where the location of the accessory, point or switchgear can be determined

from the reverse side, a zone formed on one side of a wall of l 00 mm thickness or less or partition of

l00 mm thickness or less extends to the reverse side, or

(ii) comply with Regulation 522.6.204.

Where indent (i) but not indent (ii) applies, the cable shall be provided with additional protection by means of an RCD having the characteristics specified in Regulation 415 .1.1.139
522.6.203

Irrespective of its buried depth, a cable concealed in a wall or partition, the internal construction of which includes metallic parts, other than metallic fixings such as nails, screws and the like, shall:

(i)

be provided with additional protection by means of an RCD havi ng the characteristics specified in Regulation 415.1.1,or

(ii) comply with Regulation 522.6.204.

For a cable installed at a depth of less than 50 mm from the surface of a wall or partition the requirements of Regulation 522.6.202(i) shall also apply.
522.6.204

For the purposes of Regulation 522.6.20 I (ii), Regulation 522.6.202(ii) and Regulation 522.6.203(ii), a cable shall:

(i) incorporate an earthed metallic covering which complies with the requirements of these Regulations for

a protective conductor of the circuit concerned, the cable complying with BS 5467, BS 6724, BS 7846, BS 8436 orBS EN 60702-1 , or

(ii) be installed in earthed conduit complyng with BS EN 61386-2 1 and satisfying the requirements of these

Regulations for a protective conductor, or

(iii) be enclosed in earthed trunking or ducting complying with BS EN 50085-2- 1 and satisfyi ng the requirements of these Regulations for a protective conductor, o r

(iv) be provided with mechanical protection against damage sufficient to prevent penetration of the cable bynails, screws and the like, or

(v) form part of a SELV or PELV circuit...
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0 mapj1 over 5 years ago

OK, I'm now near a copy of the 18th, and of course the actual thing is a bit wordy, so apologies for the block quote but '202 is clearly only for cables less than 50mm from surface, anything more than 50mm deep is out of scope and can be routed how you like -

however '203 which is for partition walls made with metal framework, sensibly does not have thick walls as a protection, as the wall will bring any voltage from a buried fault to the surface,and such partitions often have sharp metal edges internally that can snag a cable.

Hope this helps.

522.6.201 A cable installed under a floor or above a ceiling shall be run in such a position that it is not liable to

be damaged by contact with the floor or ceiling or their fixings.

A cable passing through a joist within a floor or ceiling construction or through a ceiling support (e.g. under

floorboards), shall:

(i) be installed at least 50 mm measured vertically from the top, or bottom as appropriate, of the joist or batten,or

(ii) comply with Regulation 522.6.204.

522.6.202 A cable installed in a wall or partition at a depth of less than 50 mm from a surface of the wall or partition shall:

(i) be installed in a zone within ISO mm from the top of the wall or partition or within ISO mm of an angle formed

by two adjoining walls or partitions. Where the cable is connected to a point, accessory or switchgear on any

surface of the wall or partition, the cable may be installed in a zone either horizontally or vertically, to the

point, accessory or switchgear. Where the location of the accessory, point or switchgear can be determined

from the reverse side, a zone formed on one side of a wall of l 00 mm thickness or less or partition of

l00 mm thickness or less extends to the reverse side, or

(ii) comply with Regulation 522.6.204.

Where indent (i) but not indent (ii) applies, the cable shall be provided with additional protection by means of an RCD having the characteristics specified in Regulation 415 .1.1.139
522.6.203

Irrespective of its buried depth, a cable concealed in a wall or partition, the internal construction of which includes metallic parts, other than metallic fixings such as nails, screws and the like, shall:

(i)

be provided with additional protection by means of an RCD havi ng the characteristics specified in Regulation 415.1.1,or

(ii) comply with Regulation 522.6.204.

For a cable installed at a depth of less than 50 mm from the surface of a wall or partition the requirements of Regulation 522.6.202(i) shall also apply.
522.6.204

For the purposes of Regulation 522.6.20 I (ii), Regulation 522.6.202(ii) and Regulation 522.6.203(ii), a cable shall:

(i) incorporate an earthed metallic covering which complies with the requirements of these Regulations for

a protective conductor of the circuit concerned, the cable complying with BS 5467, BS 6724, BS 7846, BS 8436 orBS EN 60702-1 , or

(ii) be installed in earthed conduit complyng with BS EN 61386-2 1 and satisfying the requirements of these

Regulations for a protective conductor, or

(iii) be enclosed in earthed trunking or ducting complying with BS EN 50085-2- 1 and satisfyi ng the requirements of these Regulations for a protective conductor, o r

(iv) be provided with mechanical protection against damage sufficient to prevent penetration of the cable bynails, screws and the like, or

(v) form part of a SELV or PELV circuit...
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Vote Up 0 Vote Down

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Insulated tails used to supply flats

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