"PhilÅ" wrote:
Hello

I have just installed a bathroom fan which is on a timer...

Problem is...

fixed 240 V is from a 3A spur of the a socket ring on the RCB.

the light feed is not on the RCB.

So when connected up the neutrals are now common and the RCB is tripping..

I take it I now have to connect the lighting ring to the RCB??

You should have taken all the feeds to the bathroom fan from a single
circuit, I'm pretty sure your wiring contravenes the IEE regs and, as
you've discovered, it doesn't work either!

--
Chris Green