Use of ECBs

[ppppenguin]

The best, if most expensive, way of complying with 17th edition wiring regs is a separate RCBO for each circuit. Circuits without RCD protection are only allowed in certain specialised situations in domestic premises. Very roughly, the wiring for such circuits must be surface mounted, or in armoured, pyro or other cable with an earthed outer. I think it can then feed lights or fixed appliances without further restriction but I may be wrong. It can certainly be used for fire/burglar alarms. It is possible to feed a socket outlet for a frdge/freezer but this must be clearly marked that it is only for that purpose. Ideally use a different sort of socket such as BS4343 or even old fashioned 15A BS546.

17th ed requires that the circuit be split between a minimum of 2 RCDs. This outlaws using an RCD as the main switch where one trip and the whole place is in darkness.

I'm glad I rewired my house under 15th ed regs. RCDs needed for all sockets outside the equipotential bonding zone, basically outdoor/shed/garage etc. Also any sockets that may get used for kit outside the equibond zone. Typically downstairs ring if adequate outdoor sockets aren't provided. I also protect my lab bench with an RCD. It's only common sense.

Guide to different earthing arrangements. PME has common earth/neutral conductor up to the meter. The DNO then provides you with an earth terminal whichis connected to their combined earth/neutral. http://en.wikipedia.org/wiki/Earthing_system