How much bonding?

[solo2771]

Hi everyone, can anyone tell me how much actually needs bonding under 17th edition?
I know water and gas need bonding with 10 mm and bathrooms need all metal pipes ect bonding but what about boilers hot cold water pipes from boilers ? and rads in other rooms?
I have asked several different people and got different answers.
Help much appreciated
Paul

 

[ezzzekiel]

main bonding required to gas water oil services etc, usually 10mm, although this is not always necc you can calculate the actual required size using the adiabatic equation.
supplemntary bonding is now no longer a requirement unless disconection times can not be met which is unlikely with rcd in circuit.

 

[johnnyb]

We bond gas and water 10mm, but under 17th you don,t have to cross bond bathrooms, and as above said supplementary bonding is not req, but as there seems to a lot of people using plastic water pipes, a bit of copper and a bit of plastic here there and every where, we still cross bond all the pipes, copper ones in the Imm/Htr cupboard usually, bit of belt and braces job really.

 

[solo2771]

Thanks ,
so no rads need bonding?
I thought it was a case of dependent on continuity from pipes and rads ect to MET and that kind of made sence. ie if very high resistence dont bond (less chance of shock) but under a certain amount bond?
If it was say 1 ohm and there was prob with cpc rcd would still trip but if 1000 ohm rcd may not trip and you get full fault current through your body for as long as you touch ?
Paul