Earthing bath

[theflyingpig]

and another question if anyone can help . .

I recently fitted a new steel bath to replace an ancient cast iron one. the old bath appeared earthed so I dutifully connected the cable to the new bath . . then over christmas I was replacing some floorboards and discovered a loose earth wire not connected to anything. further investigation revealed the other end of it was my bath earth - so the old bath was in fact not earthed at all.

the flat is in a block with shared cast iron wastes going to the ground -
will connecting the earth wire to the caste iron wate provide a suitable earth?

thanks!

 

[JohnD]

No.

Look up "Supplementary Bonding" on the Electrics UK forum using "Search". Look at WIKI.

As you have a cast iron drain you have to remember to bond that as well as all the copper pipes and electrical circuits (most houses have plastic wastes now).

http://www.iee.org/Publish/WireRegs/EarthingPlasticPipes.pdf

//wiki.diynot.com/electrics:sp...l_bonding:supplementary_equipotential_bonding

 

[theflyingpig]

thanks JohnD - so I have to extend this earth cable down to the main earth point in CU? or gas mains pipe?

 

[JohnD]

No. You were talking about Supplementary Bonding of the bathroom. This requires the CPC of each electrical circuit that enters the bathroom to be connected to each metallic pipe that enters the bathroom with 4mm G&Y.

The Gaspipe to the CU is Main Bonding which also needs to have been done, but is different. It requires the Main Earth of the installation to be connected to each metallic Service entering the house from outside (water, gas, oil, air conditioning ducts) with 10mm G&Y