RCD trips when shower is switched OFF

[stilllearning]

Hi, anyone got any ideas about this; a friend of mine has an electric shower which sometimes trips the RCD when he switches it OFF at the double pole pull cord switch (after first switching off at the shower)!

The RCD resets without any problem. He reckons it does it may be once or twice a week and up to now has only done it first thing in the morning. The shower has never tripped during use.

Your thoughts would be welcome. Thanks

 

[Softus]

Poor termination at the switch, or inside the shower unit?

Stray wire strand / scuffed insulation / etc.

Could even be water inside the shower unit.

I'd isolate at the CU and have a good look inside both switch and shower unit.

 

[stilllearning]

Thanks Softus.