protecting shed electrics

[dunjenkeepa]

just moved house and there is an old style 4 way consumer unit with fuses in the garage, which is connected to the main consumer unit via a 10mm cable. three circuits run off the 4 way - 1 lighting for the garage, 1 sockets for the garage, and 1 sockets for the shed.

What is the best way to improve this - just so I know what to ask when I find an electrician as I like to at least appear that I know roughly what I'm talking about!

I'm guessing I want to replace the consumer unit with a split load rcd? I have a couple of rooms attached to the garage (which is attached to the house) so I want the option of maybe adding another socket ring main or two in the future so was thinking of maybe an 8 way RCD.

Is it OK to run a seperate RCD off a main FCU with a 10mm cable ?

What type of breaker is required for an outside circuit? the cable to the shed is 4mm armoured cable, and supplies two sockets with a light spurred through a fuse.

Thx in advance for any advice

 

[MalcofArabia]

Your post is certainly getting into the realms of installation design and that is something your Electrician will do for you.

He will want to make sure that the sub main from the main board feeding your new installation will be man enough. So that 10mm^ might have to come out.

He may fit a dual board in the garage but depending on his design he may feel that a single RCD board will be sufficient as if it tripped the whole installation it might be a safer option. That again will be his call after speaking to you.

The 4 mm^ cable to the shed may well be enough to do what you want and he may keep that. He may find that after testing it, it may be unsuitable to use with RCD protection and will need to change it.

If you have a TNC_S earthing system he may have to TT the shed if the DNO do not let him export the earth, again this will need to be decided by him.

As the work to the Shed is in a special location it will have to be either notified to the LABC or he will be self certified and do this for you via his scheme.