bathroom bonding question + shower earth

[darren bergin]

I know supplementary bonding cable in bathroom does not need to go back to consumer unit but in some adverse way would it do any harm if this cable did run back to consumer unit
ALso is there a need for seperate earth wire on shower apart from twin +earths earth to run back to consumer unit..
thanks

 

[luminaire]

I know supplementary bonding cable in bathroom does not need to go back to consumer unit but in some adverse way would it do any harm if this cable did run back to consumer unit

No.

ALso is there a need for seperate earth wire on shower apart from twin +earths earth to run back to consumer unit..

Yes, shower should be supplementay bonded.

 

[GaryMo]

Depends on where circuits are located within your bathroom, also depends on if pipework is plastic or copper.
If plastic then you need to link the cpc terminals of each circuit which falls into zone 1, 2 or 3, eg, link shower to light (or switch) to electric towel radiator.
If pipework is copper then you need to link each cpc terminal of each circuit which falls into zone 1, 2 or 3 to copper pipework within the bathroom (under floorboards or in loft will do). Also cross-bond hot to cold etc.
Use 4mm2 6491X.

It's highly unlikely that you'll need a separate CPC for your shower if you're using standard t&e cable - 6mm (2.5mm cpc) or 10mm (4mm cpc).
The only way to know for sure is to calculate the minimum cpc size required for the shower circuit using the adiabatic equation and ensure that the cpc you have is larger.

 

[GaryMo]

ALso is there a need for seperate earth wire on shower apart from twin +earths earth to run back to consumer unit..

Yes, shower should be supplementay bonded.

That's not what he's asking.....