"Tim+" wrote in message
...
bert Wrote in message:
In one bedroom we have a ceiling fan supplied from the lighting circuit.
It's been there for over 10 years no problems.In the past few nights a
couple of times when switching it off the RCD protecting the ring mains
has tripped. But the lighting circuits don't go through it and the lights
are still on including the one which is part of the fan and the fan
itself can be switched back on.Puzzled as to how this can happen - and
where to start looking.-- bert

It would suggest that it's not supplied by the lighting circuit...

Are you sure that your RCD *only* protects the ring mains and not *all*
circuits such as cooker, lighting in addition to ring mains?

My understanding is that an RCD in the "fuse box" is usually upstream of the
ring main MCBs (over-current sensors, equivalent to wire fuses) and protects
the whole house. Our previous house had two RCDs: one was a separate unit
that was between the meter and the fuse box, and the other was within the
fuse box. Even if the RCD within the fuse box was tripped, all power went
off, including to non-ring-main circuits such as lighting and cooker.


What happens if you manually turn off the RCD? Does the lighting still
continue working?