Bathroom Supp. Bond

[seasickstevie]

Always feel a bit unsure about the Supplimentary Earth Bond in the bathroom.
Rad to h&c is 4mm I believe.

What is the minimum csa for Supp. Bond from 6mm shower cable to lights/fan?

Think it's 1.5mm but does anyone think different?

 

[plugwash]

iirc the minimum for a seperate supplementry bonding conductor is 2.5mm (or maybe it was 1.5 I don't remember for sure) with mechanical protection (which you very rarely have for the entire run) or 4mm without it. However the earth conductor of a sheathed cable can be used as part of the bonding even if it is smaller. You can also use copper pipes as part of the bonding provided they are soldered together.

 

[Steve3948]

Remember that some showers already have the bond to pipe internally.
Mira are one of those who have an internal bond.
Triton do not.