Wiring / Electrical / Insulation help

[Rikki]

Gramaisc's explanation is spot on. Only thing I would say is in your pic there seems to be a cable missing from the main switch to the neutral bar, which normally comes pre installed.

 

[Gramaisc]

You just need a decent piece of wire for that, but there's no reason why it shouldn't have been pre-fitted. It connect all the neutrals that are brought to the connector block back to the bottom right terminal of the RCD. It will carry the entire neutral current. The bigger the better, but bear the load in mind when deciding on the size. There seems to be no main switch, just the two pole RCD. That's OK for an extension box, but it would be nice to have the switch as well, if it's for the whole house installation. If the MCBs aren't all identical then the number on the front usually will include the rated curent in Amps.

There are specified standards for all this but reality will suffice.

 

[tek-monkey]

Thanks for your help guys, it was the neutral that threw me. I was assuming earth as the long top bar, but then didn't know why there were 2 short others - I expected them to be joined giving 2 banks of 8.

I had the choice between switch or rcd, went for the rcd as it was an extension box. Although its better than what's installed in the house!

 

[Gramaisc]

Yes, definitely have the RCD - especially for outhouse situations and pond pumps. It's nice to have a main switch for the actual incoming situation for the whole premises, it gives better isolation than an open RCD can on its own. A switch on the supply side of an RCD for the live and neutral - then to a common neutral point and a live busbar - and then on through the individual MCBs for the lives to each circuit.

 

[tek-monkey]

Fuse box is in place in the shed, have wired the SWA cable in and fixed it to the wall in several places - it aint moving! Not wired up the house end yet though, need to properly route it in the garden and its too fookin wet for that today! Tested the lights and all work bar a 3' tube in one, so not bad for 8 quid. Now I need to rearrange the workbench n stuff to decide where all the sockets are going.

Getting there, slowly...