earth bonding

[eldiablo]

Hi
I have just moved a bathroom into a smaller room and have just about finished but I want to earth bond the pluming etc, there is no electric shower in the bathroom. The shower is fixed from the wall above the bath and it is fed from a deck mounted diverter and controlled via the hot and cold bath taps. All supply piping comes up from the kitchen underneath the new bathroom. The bath is a jaccuzi and the pump and is supplied via an isolation switch outside the bathroom. Now i was going to earth bond the pipes together and run a new earth wire back the consumer unit where the downstairs bonding runs but i have read that bathroom earth bonding must be run back the the earth point of the supply to any electrical equipment in a bathroom so my question is do I bond the pipes in the bathroom and run the earth to the earth of the supply box outside the bathroom ?
Many thanks for any help recieved

Regards Chris

 

[ricicle]

Are all the electrical circuits in the bathroom protected by a 30mA RCD and your Main Equipotential Bonds in place ? If so then you can omit supplementry bonding in the bathroom.

If there is no RCD (hopefully still MPBs in place) then any pipework entering the bathroom will need bonding with min. 4mm² earth wire to each other and all electrical circuit CPCs in the bathroom. This does not need to run back to the consumer unit.

 

[riveralt]

How a little knowledge can be so dangerous.
The first thing to ask is do you actually need supplementary equipotential bonding in your bathroom? Just to clarify this means bonding earth cable between all the exposed conductive metal parts and running the cable back to the main earthing terminal via an electrical point's earth - possible a nearby socket or lighting circuit ceiling rose.
Whether you need to do will depend on the extent of your main protective bonding and your Consumer Unit.
You need to check that your water, gas and any other service pipes are bonded directly back to the main earthing terminal.
//www.diynot.com/wiki/electrics:main_equipotential_bonding

Under the 17th edition regulations (BS7671:2008) supplementary bonding in a bathroom may be omitted where certain criteria are met. These criteria are as follows:

All circuits comply with the requirements for disconnection times
All circuits are RCD protected by a 30mA device maximum
All exposed conductive parts in the location are effectively connected to the protective equipotential bonding.

See
//www.diynot.com/wiki/electrics:speclcn:supbond17th