New CU

[londoner1]

Need some advice.

Had the CU upgraded to 17th edition as part of loft conversion, all been signed off and BC cert has arrived.

Have a question on power sockets, the sockets are all under 32A MCB'S, i just noticed it now, is this ok? I though its normally 16A/20A MCB'S?

 

[Simon35]

Perfectly fine if they are ring circuits, which is most likely, but I can't tell from here.

Not fine if they are radial circuits, which is less likely, but again, I can't tell from here.

 

[Taylortwocities]

Had the CU upgraded to 17th edition as part of loft conversion

So, the work was notified and certified?
Therefore you have a copy of the installation certificate?
This will tell you if the circuit has been configured as a ring.

 

[ban-all-sheds]

I though its normally 16A/20A MCB'S?

Normally in the UK they are 32A circuits.

 

[EFLImpudence]

the sockets are all under 32A MCB'S,

Because of the cable used; not because there are sockets.

 

[Iggifer]

Not fine if they are radial circuits, which is less likely, but again, I can't tell from here.

Well that's just incorrect

 

[ban-all-sheds]

It might be.

Or it might not be.

 

[Iggifer]

It might be.

Or it might not be.

True. But as a blanket statement like that, it's incorrect.

For the benefit of the OP, if they are radials wired in >4mm² cable, they're fine on a 32A OPD. If the cable is <4mm², and it's a radial on a 32A MCB, that is indeed, not fine.

 

[ban-all-sheds]

What if the cable is =4mm²?

 

[chivers67]

not larger than 75m square

 

[RF Lighting]

Because?

 

[Simon35]

It might be.

Or it might not be.

True. But as a blanket statement like that, it's incorrect.

For the benefit of the OP, if they are radials wired in >4mm² cable, they're fine on a 32A OPD. If the cable is <4mm², and it's a radial on a 32A MCB, that is indeed, not fine.

Seeing as we're splitting hairs....

Not fine, in that it might need some consideration as to whether the cable size is adequate for the OPCD.

 

[ban-all-sheds]

What considerations would make a 2.5mm² cable adequate for a socket radial on a 32A device?

 

[Simon35]

What considerations would make a 2.5mm² cable adequate for a socket radial on a 32A device?

The OP would need to consider whether the cable size as installed is less than 4mm or is at least 4mm.

The OP might also like to consider whether the circuit is a ring or a radial.

"Consider - look attentively at"

 

[Iggifer]

What if the cable is =4mm²?

Yea I forgot to underline my >