Earthing Metal back boxes and matal face plates

OTT in my book, but the IEE say otherwise. (Wonder if they have shares.... and other unworthy thoughts)

However on a practical note, crimp a ring on your stub of earth wire and put that under the fixing screw.

"John Borrman" wrote in news:culjt6$8if$ snipped-for-privacy@newsg1.svr.pol.co.uk:

Yes, and if your back boxes haven't got an earth terminal they need replacing.

You can't rely on the earth provided by the faceplate screws

mike

Would it suffice under IEE regs as Andrew recomended to crimp a earth wire to ring and connect this to the fixing screw? Its just that all walls have been plastered and painted now.... cant face replacing all the face plates.

"John Borrman" wrote in news:cun4n9$eld$ snipped-for-privacy@newsg1.svr.pol.co.uk:

I'm not an expert, and I may have misunderstood his post, I took it to mean that a good earth to the faceplate was enough.

But looking back, if he meant fabricate a good earth to the box, and continue it to the faceplate, I'm sure that's ok.

(Can't see his post any more, me reader's thrown a wobbly, I must have hit a wrong key by accident)

pikey mike

Cheers for that, rather fabricate an earth than replace all the boxes....

I would add a corrugated washer between ring and metal of box to give it some bite.

Dave

They must be pretty old metal boxes without earth terminals?

However, if it's messy to change them, I'd crimp an eye terminal onto the earth 'tail' and fix it to the box with a self tapper.

IF we're talking about flush metal mounting boxes that are sunk into the wall (i.e. not accessible when the wiring accessory is in place),

AND the wiring system is twin-and earth and, explicitly, is NOT MICC or metal conduit, where the earthing is provided by the metal sheath of the cable or the conduit, via the mounting box,

AND the metal face plates each have an earth terminal,

THEN it's OK to connect all the incoming earth wires to the faceplate terminal and there's no specific requirement for a separate earth wire to the back box. The box (which is not an exposed-conductive-part in these circumstances) will be earthed via the accessory mounting screws.

Andy - this sounds far too sensible for the IEE regs. Are you sure this is correct as everybody else seems to think the wire is needed, including that apprentices thing on TV a few weeks back.

That said, I've never put it in either as I think it has no useful purpose and until Part P came along was allowed to argue so.

It's required in the circumstances where the earth (CPC) is supplied _to_ the box first through metal conduit, etc. - otherwise I'll stand by my interpretation.

I saw that and it involved metalclad fittings and metal conduit. I don't think the conduit was providing the CPC, but it and the boxes were certainly accessible (exposed-conductive-parts) so needed to be reliably earthed. Quite a different situation to what we're talking about here.

Thanks. I'll refer the BCO to you if he complains :-)

Probably best to discuss it with him - or whoever's going to do the inspection - first to avoid any surprises.

It's already done that way as it was started two years ago long before part P. Desperately trying to get all the wiring finished before March