Bathroom light ip and main bonding?

[graham123]

If a bathroom light is out of the zones but directly above the shower does this not need up rating? Eicr no code?

Main bonding to water and gas tncs must be half of the supply neutral. Do you count the incoming cable to the service cutout as the incoming? Or the tails from top of cutout to main panel? What would you write in the primary supply conductors on an nic form?

 

[Richard Burns]

The bathroom light, if out of zones, needs to be suitable for the location and the external influences, general rules for BS7617 apply.
You do not say why a light would need to be changed, an IP65 bathroom downlight would be fine, a pendant would be quite stupid.

Main protective bonding on a TNCS supply is minimum 10mm² (larger if the supply neutral is larger than 35mm²) (1/2 N min 6mm² is for non PME)
Theoretically the incomer to the cutout is the size of the supply cable but this is generally impossible to determine, so go by the csa of the smaller of the meter tails (in or out).

 

[graham123]

Thanks richard, the supply into the cuto is a 95mm 4core swa, then from cutout to main panel is 185 tri rated. With 25mm bonding to water and gas. Would you recorded the 95mm as your primary conductors?

 

[Richard Burns]

It is not often the DNO use SWA as a supply cable but if they have then that is the the size to work from.
with a 95mm² neutral supply then 25mm² is the minimum bonding.