Departures from regs

[nrbspark]

I have been asked by a local authority to bring an installation in line (within reason) with the 17th edition with no disturbance, so my questions are as follows guys: Bearing in mind it is a TN-S supply and all insulation resistance and live tests are well within current limits.

1 Tails 16mm and approximately 5m in length (no DP isolator at electric board incomer).
2 Main earth is 6mm.
3 There is only 1 ring main at the property with 11 outlets.
4 Gas earth is 6mm.
5 Water earth is 2.5mm.

I spoke to the NICEIC tech helpline and was not entirely happy with the advice I was given, so I would be grateful if some further opinions on the items listed above could be given.

Just to point out that the local authority would rather that a re-wire was carried out, but because of the objections from the tenant due to health reasons an upgrade is being carried out.

Cheers Guys

 

[diditrain]

Why dont you get someone from the local authority round to see what the tenant will agree to have done, then get them to specify in writing the upgrade that they want you to do. Cover your own ---

 

[Davey101]

Good point, I should think the local authority would have their own M+E engineer or clerk of works who could decide what they wanted. I cant see how its up to you to decide what work they want carried out. I guess the easiest thing to do would be to tell them what doesnt comply, and then detail the disruption each item would cause, its up to them then what work they want carried out.

 

[Sintra]

I have been asked by a local authority to bring an installation in line (within reason) with the 17th edition with no disturbance, so my questions are as follows guys: Bearing in mind it is a TN-S supply and all insulation resistance and live tests are well within current limits.

1 Tails 16mm and approximately 5m in length (no DP isolator at electric board incomer).
2 Main earth is 6mm.
3 There is only 1 ring main at the property with 11 outlets.
4 Gas earth is 6mm.
5 Water earth is 2.5mm.

I spoke to the NICEIC tech helpline and was not entirely happy with the advice I was given, so I would be grateful if some further opinions on the items listed above could be given.

Just to point out that the local authority would rather that a re-wire was carried out, but because of the objections from the tenant due to health reasons an upgrade is being carried out.

Cheers Guys

A main switch must be provided to cut off the voltage to an installation. 132.15.1

The minimum csa of the main earthing conductor must be determined by the adibiatic equation or selected from Table 54.7 543.1.1. If the adibiatic equation is used, the minimum csa of the main earthing conductor may be 6mm 544.1.1. Table 54.7 suggests a 16mm main earthing conductor for phase conductors with a csa of up to 35mm.


For TN-S or TT systems the csa of main protective bonding conductors must be a minimum of 6mm and not be less than half the csa of the main earthing conductor. 544.1.1

A ring final circuit must not serve a floor area greater than 100m2. p362

Also RCD protection as required.

 

[ian3012]

check onsite guide 2.2.3 ..if you're looking for extra work....the maximum length of the tails allowed is dictated by the distributor... if they say 5m is too long...the jobs a duffer anyway.... the housing authority will have to move the tenant while you rewire!