Question raised by neighbor ...
He has 3ph & Neutral supply (temp supply) on a new build.
He wants to have one 3 ph circuit in garage, to a couple of outlets ........and a single phase supply to house.
He asked me what way should he be preparing the wiring for final connections ...
My assumption would be .. TPN to main isolator. (A) The output of that providing two feeds;
1) One feed to a 3ph distribution board ... fitted with a TPN isolator, and then a TPN mcb for each circuit.2) Second feed would be SPN ... 'tails' to his consumer unit.
The main isolator (A) providing full isolation of the supply, the TPN isolator on dist board allowing isolating of 3PH circuits The standard DP switch on Consumer unit providing isolation of the house install.
If the above is OK .... a second Q ... In the garage which is the only part of house to have 3ph ... there will also be outlets on a standard 220V ring final circuit.... can these be fed from the main consumer unit ? ... or do they have to come from the 3ph dist board.?
Just wondered if there was any regulation that required SPN circuits to be isolated at same time the TPN is isolated .... you could turn off distb board isolator and assume all was 'safe' whereas in fact the SPN outlets would still be live.
Full isolation is provided by the main 'incoming; isolator (A)