2 RCD's on circuit

[HandySparks]

Is that a point open to debate though - if you TT an outbuilding should you have it's own RCD in there too (even if the upfront one will protect)? Or would you say it's perfectly acceptable to have an RCD at the CU, TT the outbuilding, and not install a second RCD at the outbuilding.

I can't see the point of a local RCD if the supply is on an RCD. After all, it doesn't make any difference whether earth fault current returns entirely via a copper wire or via the bulk of the earth to the star point of the local supply transformer.

 

[rolyberkin]

Surely the point of a local RCD is convenience in resetting. Best to feed the MCB via swa from a non RCD protected MCB, that way if the RCD trips you don't have to traipse back to the house to reset.

 

[Leader]

My tutor said that you should run SWA from a Henley block to the new CU which will then have it's own main switch etc. Is that just overkill?

 

[HandySparks]

My tutor said that you should run SWA from a Henley block to the new CU which will then have it's own main switch etc. Is that just overkill?

Ask your tutor how he would terminate SWA into a Henley block using the correct gland and without leaving the insulation exposed. And what would he be using for fault protection on the SWA?

 

[kingeri]

My tutor said that you should run SWA from a Henley block to the new CU which will then have it's own main switch etc. Is that just overkill?

What, without overcurrent / fault protection?

 

[Leader]

Yes, thinking about it, it does sound crazy, but then he did actually get fired half way through my course due to his, er, eccentricity. I'll make sure I change my notes on that!!

 

[westward10]

My tutor said that you should run SWA from a Henley block to the new CU which will then have it's own main switch etc. Is that just overkill?

I think your tutor may of meant to make the cable off in an enclosure at the TT end, fit service terminal blocks in the enclosure to supply the board. Then again he may have been a fruit loop.