Kev wrote:

In which case surely the RCD would trip. Seeing the minute amounts of
condensation that cause my RCD to trip I have absolute confidence that
water ingress into a pump would give the RCD no problems with
detection.

no safety method is failure proof, hence we use several in combination
to get excellent safety.

Having said that I wish I could more than ten years out of a
submersible pump. I have just had to chuck a 3000 gallon per hour pump
away that tripped the RCD due to very slight water ingress through a
worn cable. The pump ran quite happliy on an unprotected circuit. This
was a £200 pump. It was repairable but coming close to £200 to repair
it was it worth it. It was 10 years old so time for the dump.

cables can be replaced and the pump resealed in minutes. Applying dc
first would get rid of much of the ingress.


NT