EICR failed. Old installation, lighting circuit on 1 mm2

[Cooper_day]

Hello everyone,

An EICR failed due no RCD protection at all(only 3036 fuse), no bonding on gas and water, small csa earthing conductor. All will need to be bring to BS7671 standards.

The lighting circuit is on 1 mm2, does it need to be increase to 1.5 mm2 to meet the standards(e.g. lighting circuit need to be rewired)?

Thank you

 

[Lister1987]

Hello everyone,

An EICR failed due no RCD protection at all(only 3036 fuse), no bonding on gas and water, small csa earthing conductor. All will need to be bring to BS7671 standards.

The lighting circuit is on 1 mm2, does it need to be increase to 1.5 mm2 to meet the standards(e.g. lighting circuit need to be rewired)?

Thank you

What does your engineering judgement say? Have you attempted to calculate the expected load?

OSG Chapter 7, Table 7.1(I) and 7.1(ii) should help you in determining of it is compliant

 

[brianmoooore]

No 'normal' domestic property needs its lighting circuits wired in anything other than 1mm2.
A 3036 board does not contravene regulations per se, but my personal opinion is that the only place these should still be is as museum exhibits.
The RCD bit is open to debate, but again, my personal opinion is that they should be present, which, of course, they will be, if the 3036 board is replaced.
Water and gas may not need bonding, dependant on the circumstances, and earthing conductors often turn out to be big enough if calculated, rather than going by convention.

 

[Cooper_day]

What does your engineering judgement say? Have you attempted to calculate the expected load?

OSG Chapter 7, Table 7.1(I) and 7.1(ii) should help you in determining of it is compliant

He put C2 on bonding, absence of RCD and small CSA on main earth. Load calculation has not been carried out yet.

If I look at the OSG you can use 1 mm2 within a max length of 68mt but the installation method used in the property(B) is not present on the table.

 

[Lister1987]

He put C2 on bonding, absence of RCD and small CSA on main earth. Load calculation has not been carried out yet.

If I look at the OSG you can use 1 mm2 within a max length of 68mt but the installation method used in the property(B) is not present on the table.

Are you sure? B is trunking or conduit. Method A however (enclosed in conduit in an insulated wall) which IS permitted so the table should still help you

 

[MJPD29]

If 1mm is calculated to be capable of carrying the current required then no jt does not need to be rewired.

 

[brianmoooore]

With LED lamps, it'll be a large and very bright house that puts 1mm2 anywhere near its current limit.

 

[naylorpd]

My 2016 new-build house, 5 bedrooms over 3 floors (i.e. must be more than 68m of cable per circuit) is on 1mm cable for the lighting circuits. Since you'd struggle these days to find a light bulb over about 7W that used to be 40-60W it seems unlikely that you'd need to rewire back up to 1.5mm

 

[pc1966]

The OSG length is for the max MCB rating of 6A uniformly distributed on a radial and 3% voltage drop. That is worst-case for a home with filament lamps. Basically in practice you won't see that on LEDs, and most homes won't have 68m end-end in use, as the "radial" for lights is more like a tree in practice.

C2 for no RCD and no (adequate) supplementary bonding in a bathroom or kitchen is reasonable in in line with the BPG#4.

Lack of main bonding to service pipes is always a worry and potential C2 on TN-C-S as an open PEN could start a fire if only a boiler's 0.75mm CPC is there to carry the current, etc. Obviously if service pipes are plastic then not an issue, but if in doubt they ought to be adequately bonded.