Sub Main and Fusing

[daver]

Hi guys and please dont shoot me down. I qualified this time last year, but due to family commitments, I have not been active for nearly a year, so a little rusty.

Just started a rewire on a new extension on an old victorian house. Easiest option was to run new 16mm tails and 16mm earth, 5m into extension and have seperate consumer unit for extension circuits.

With diversity it will be roughly 45A per CU.

Its TNS and Manweb have 16mm tails to 100A fuse and main switch, so the questions are.

Will Manweb need to upgrade to 25mm.

From the 100A switch would you split and insert Fused Isolators to each CU.

Thanks in advance.


Dave

 

[Notsosmart]

100 amp fused switch should be 25mm tails so yes I would either ask manweb to change these or advise them that you are changing them & seek permission to cut the seals.

The two CU's should be fed by one fused switch to give one point of isolation.

Personally I would feed the CU's with 25mm as well.