shower wiring help

[duksey]

my house has just been rewired.I asked the sparkys to put the wiring in so i could fit an electric shower which they did.i have baught a 8.5kw shower and a pull switch.as it stands i have a thick grey cable and a seperate green and yellow cable from the loft to where the shower head will be.in the celing i have a hole with 2 grey cables and a loop of green and yellow cable coming through.question is which earth do i use? the bare earth in the grey cable or the seperate green and yellow one.hope this makes sense.(thick geordie)any help welcome.thanks duksey

 

[Taylortwocities]

I imagine that the earth cable is the supplementary bonding. If that is the case then this earth should be bonded onto the pipework of the shower. The grey supply twin & earth goes to the shower itself.

 

[RF Lighting]

Surely the seperate G&Y cable is a supplementary earth, and should be connected to the CPC of the shower circuit, as the cold water pipe will already be bonded?

To OP can you see any earth clamps on the pipework supplying the bath or basin taps?

 

[TicklyT]

Or has a seperate earth been run as here:-

http://www.diynot.com/forums/viewtopic.php?t=91781

 

[Taylortwocities]

Lots of possibilities, I think the OP should ask the spark who installed it where the G/Y wire comes from...

 

[duksey]

thanks for replys.the plumbing was done after the electrics and yes i do have g&y earth straps on wash basin.will check if there's a strap att to cold water feed.I cant contact the sparky who did the insulation as they were contracted by the council.a mate is calling round tomoz ill post the outcome many thanks for your help.duksey