Earthing a bath

[Mike2007]

I have a bathroom without an electric shower, there is supp-bonding on copper pipes and bath.
There is lighting of course, but do I need to find a CPC in a circuit for the whole lot to connect to (for a true earth path)?
Could I use a cpc in another room, a socket for instance?
Thanks

 

[Lectrician]

That is not how supp bonding works.

It is to connect all extraneous conductive parts together and to each CPC or the circuits WITHIN the bathroom - Lighing, shower, towel rad etc etc.

No need to 'earth' this bonding - it is simply to make sure all the parts WITHIN the room are at the same potential during a fault.

 

[Mike2007]

So when is a circuit cpc unitised in a bathroom, only when there is an out let (shaver socket) or shower?
What is the point in making all item equal in potential? That is, if the bath became live why would you want that to be connected to the rad as well?

 

[Lectrician]

Not necessarily 'live', but raised in potential through a fault with some impedance.

If you are holding two metal items - a bath and a radiator at the same time, and one is earthy, and one goes faulty, there is a potential across them to give you a belt. If the two are bonded together, there is no potential between them, and no shock. Theoretically.