Sorry for the long one.
Hi. I have just installed a garage consumer unit in my shed with a 40a 30mA RCD, a 32a MCB and 1 x 6a MCB (The BG 5 module one out of Screwfix) I ran 6mm swa cable approximately 35m from the main board in the house. I’ve wired up a ring in the shed and switched it all on. No problems. I plug a radio in and switch it on, as soon as I draw any power, the RCD in the shed only trips. It happens on every socket outlet. I’ve checked for damage to the cables, checked that I’ve got the polarity correct in the outlets, checked for continuity on the live, neutral and earth, checked for leakage, but there’s nothing wrong with the circuit?!?!
So I then took everything out of the MCBs and wired in a single socket just loose hanging from the consumer unit. I turned it all back on, plugged in a small sander (the only thing I had handy) and the second I switched the sander on, the RCD trips. At least I now know there is nothing wrong with the sheds wiring. So that’s a positive. Lol.
Back in the house the swa goes into the split load fuse board via a 32a MCB. There is a 100a RCD protecting my shed circuit and 4 others (2x32a and 2x6a) just sockets and lights on that side, nothing big. I’ve wired the 6mm SWA into the correct neutral and earth bars in the consumer unit.
Any thoughts what is causing this? Could the RCD in the house and the RCD in the shed be working against each other? I know you don’t really need 2 RCD’s, but I was thinking that if there was a fault in the shed, it would trip that out and leave the house alone.
This is really doing my head in. Any thoughts? Thanks in advance. Si
Hi. I have just installed a garage consumer unit in my shed with a 40a 30mA RCD, a 32a MCB and 1 x 6a MCB (The BG 5 module one out of Screwfix) I ran 6mm swa cable approximately 35m from the main board in the house. I’ve wired up a ring in the shed and switched it all on. No problems. I plug a radio in and switch it on, as soon as I draw any power, the RCD in the shed only trips. It happens on every socket outlet. I’ve checked for damage to the cables, checked that I’ve got the polarity correct in the outlets, checked for continuity on the live, neutral and earth, checked for leakage, but there’s nothing wrong with the circuit?!?!
So I then took everything out of the MCBs and wired in a single socket just loose hanging from the consumer unit. I turned it all back on, plugged in a small sander (the only thing I had handy) and the second I switched the sander on, the RCD trips. At least I now know there is nothing wrong with the sheds wiring. So that’s a positive. Lol.
Back in the house the swa goes into the split load fuse board via a 32a MCB. There is a 100a RCD protecting my shed circuit and 4 others (2x32a and 2x6a) just sockets and lights on that side, nothing big. I’ve wired the 6mm SWA into the correct neutral and earth bars in the consumer unit.
Any thoughts what is causing this? Could the RCD in the house and the RCD in the shed be working against each other? I know you don’t really need 2 RCD’s, but I was thinking that if there was a fault in the shed, it would trip that out and leave the house alone.
This is really doing my head in. Any thoughts? Thanks in advance. Si