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shocksmith222

Hi All,

I am a newbie to the forum so please be gentle! :eek:

Today I have come across a recently rewired house and I noticed that the installing sparky has indicated on the Install Certificate that the lighting circuit is T&E 2 core 1.5mm and CPC 1.5mm. However, I have noticed that in fact there appears to be several runs where T&E 2 core 1.5mm and CPC 1.0mm has been used instead.

From a testing point of view it is fine and Max Zs is well within the Regs guidelines. I am just wondering 2 things and despite checking my regs cant find any 100% answer.

1. For the certificate - should it actually have been issued stating the smaller T&E 2 core 1.5mm and CPC 1.0mm rather than as it is now T&E 2 core 1.5mm and CPC 1.5mm?

2a) Am I obliged to advise the client that the T&E 2 core 1.5mm and CPC 1.0mm should now be replaced with the same cable as used in the majority of the lighting circuit, that is T&E 2 core 1.5mm and CPC 1.5mm
OR
2b) Can I simply leave it as it is and just advise the client that there is a mix of CPC size on the lighting circuit. Afterall the safety disconnect of the circuit is fine anyway.

Thanks to all in advance for your views.
 
Hi All,

I am a newbie to the forum so please be gentle! :eek:

Today I have come across a recently rewired house and I noticed that the installing sparky has indicated on the Install Certificate that the lighting circuit is T&E 2 core 1.5mm and CPC 1.5mm. However, I have noticed that in fact there appears to be several runs where T&E 2 core 1.5mm and CPC 1.0mm has been used instead.



From a testing point of view it is fine and Max Zs is well within the Regs guidelines. I am just wondering 2 things and despite checking my regs cant find any 100% answer.

1. For the certificate - should it actually have been issued stating the smaller T&E 2 core 1.5mm and CPC 1.0mm rather than as it is now T&E 2 core 1.5mm and CPC 1.5mm?

2a) Am I obliged to advise the client that the T&E 2 core 1.5mm and CPC 1.0mm should now be replaced with the same cable as used in the majority of the lighting circuit, that is T&E 2 core 1.5mm and CPC 1.5mm
OR
2b) Can I simply leave it as it is and just advise the client that there is a mix of CPC size on the lighting circuit. Afterall the safety disconnect of the circuit is fine anyway.

Thanks to all in advance for your views.

I didn't know that you could get 1.5mm T&E with a 1.5mm cpc I thought all 1.5mm T&E had a 1mm cpc.
 
I didn't know that you could get 1.5mm T&E with a 1.5mm cpc I thought all 1.5mm T&E had a 1mm cpc.

Same here.

But in answer to the hypothetical question, I would list the smallest csa present for the cpc.
 
As pennywise said, record the smallest value. it's quite common to see mixed conductor sizes. One common practice was to wire the circuit in 1.5 and use 1.0 f or the switch drops.
 
Hi - I've got the same issue at the moment: I'm, doing a pvc conduit installation using 1.5mm single core cpc on the lighting circuits in conduit (no supplier could get me 1mm single core), however there are places where I am going over to 1.5mm/1mm twin & earth outside conduit, where it seems sensible to do so.:) Is this OK?
(First post! - whew)
 
Hi - I've got the same issue at the moment: I'm, doing a pvc conduit installation using 1.5mm single core cpc on the lighting circuits in conduit (no supplier could get me 1mm single core), however there are places where I am going over to 1.5mm/1mm twin & earth outside conduit, where it seems sensible to do so.:) Is this OK?
(First post! - whew)

It's fine! Just record the smallest CSA on the cert, and you could also note the differing sizes too. If Zs are OK then what's the issue?
 

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