Garage supply - Cable

[Dambo]

Hi guys, quick question regarding supplying a garage consumer unit:

Is an IR test required at the main house CU (supplying the garage CU) to ensure that the cable supplying the garage CU is sufficient?

 

[matt.leung]

ur supply cable to the garage needs an IR test.

Also i take it that it is a new circuit from the main consumer unit....

 

[Andy™]

IR test only checks for insulation breakdown. it will not in any way help determine if cable is sufficient for use. this is down to the designer to ensure cable is adequate for use

however, it the cable is well undersized and constantly hot and destroys its own insulation, then an IR test will confirm it was too small and needs replaced

 

[Dambo]

ur supply cable to the garage needs an IR test.Also i take it that it is a new circuit from the main consumer unit....

No, the feed from the main CU is already in place. I'm rewiring the garage and installing a separate CU. I just wanted to make sure I needed to test the supply cable.

[quote name='Andy

 

[sparkytim]

Have you asked this before? De' Ja Vue

You do not HAVE to test the Insulation resistance of an existing part of the supply to an installation you have installed, just the Zdb (Which is the Zs of the supply circuit) PFC and confirm polarity.

But it would do no harm to and would confirm that no existing problem was likely to affect your NEW work.

Why do you ask? Is it going to be a problem to do it?

 

[Dambo]

Have you asked this before? De' Ja VueYou do not HAVE to test the Insulation resistance of an existing part of the supply to an installation you have installed, just the Zdb (Which is the Zs of the supply circuit) PFC and confirm polarity.

But it would do no harm to and would confirm that no existing problem was likely to affect your NEW work.

Why do you ask? Is it going to be a problem to do it?

I have already asked some related questions but I just wanted to be clear about the supply cable.

It may not even be an issue but the existing wiring in the garage isn't great so i'm anticipating that they supply cable, which is buried, might not be upto scratch either.

 

[paul b b]

what size cable is it?

are you intalling a garage unit with a 6A & 16A?

it really depends on what they want to do in there, if its just a few sockets and a light or are they running lots of power tools etc...

 

[Dambo]

what size cable is it?are you intalling a garage unit with a 6A & 16A?

it really depends on what they want to do in there, if its just a few sockets and a light or are they running lots of power tools etc...

Aye, it is a garage unit with a 6A and 16A MCB. The supply cable is 2.5mm. There's only one light in the garage and the sockets will only occasionally be used and not for anything demanding.

 

[paul b b]

thats fine (unless its miles away), megger the cable if its fine use it but note it on the cert that you did not install