On 27/07/2019 14:45, Andy Burns wrote:
Tufnell Park wrote:

There is a well established procedure for detecting which circuit is
causing an RCD to trip.

Viz with the RCD off switch off all mcb's.
Reset the RCD
Turn on each mcb in sequence to determine which circuit is causing the
RCD to trip.

Or if you're unlucky you find it's several of them together, or it's
intermittent.

That's only if you are unlucky, most of the time it works!