New installation to outbuilding

[DRDAVIDBANNER]

I'm new to the forum to Hi!

I'm putting an installation into a Log cabin in my parents garden, I've installed the cabling installed a separate 2 way RCD protected CU in the cabin. The cable is earthed at the main CU in the house and protected on the main CU by another RCD. However I want to achieve discrimination between the 2. I see a couple of options I'd like to know if anyone is sure on the regs for this as I can't seem to find it in BS7671:2008

1) Install a time delayed RCD in the CU in the house.

2) - (This is the option I am, unsure about). - As the building is a fair distance from the main property, I'd like to earth it separately (TT system), if I do this, do I keep the cable earthed at the main CU? If I keep it earthed at the main CU does it make the entire installation a TT system since the new earth rod will essentially be connected to the main earthling terminal.
- Also if I do connect it at both ends will I still get discrimination

I hope this is clear,

thanks in advance - Pete

 

[Engineer54]

Depends a bit on how helpful your LABC are. Mine were happy to inspect after I had changed the CU urgently when we moved in (lots of probs on old installation), and then re-inspect after I had done a complete re-wire and tested/self-certified, all on the one notification and payment. Same again for loft conversion electrics later. Am not on any competent persons scheme (but am a Chartered Electrical Engineer).

You might have more trouble if you have started the work already!

And there, .....IS the very big difference!! lol!!! No-one's going to argue with you on your installation are they, ....not unless of course you made a ''Blatant'' mistake somewhere!!
Could be very much different, if you were say an industrial electrician rewiring his home
and not too sure of some of the finer points of domestic wiring...lol!!

 

[ackbarthestar]

And there, .....IS the very big difference!! lol!!! No-one's going to argue with you on your installation are they, ....not unless of course you made a ''Blatant'' mistake somewhere!!
Could be very much different, if you were say an industrial electrician rewiring his home
and not too sure of some of the finer points of domestic wiring...lol!!

Possibly .... but I suspect, that the LABCs and the part P authorizing bodies would be far happier that all electricians went down the self-certification route, for all sorts of reasons.

 

[Engineer54]

Possibly .... but I suspect, that the LABCs and the part P authorizing bodies would be far happier that all electricians went down the self-certification route, for all sorts of reasons.

Well the LABC's also have the means to provide that facility, by putting those electricians that are suitably qualified, on there ''Approved'' register. By not doing this, seems to be based on monetary income, than anything else. ...Unless i'm missing something here?? lol