In article , Tim+
writes
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...

Tim
But its definitely not supplied by any circuit protected by the RCD.
--
bert