three phase board separation

[pc1966]

This is what you need to replace the rcd switch.

That is a good price. I was going to say you can probably buy just the switch on its own, but depending on your local trade outlet stock/staff levels, that might be the best option.

 

[davesparks]

Maybe others will have better ideas?

Yeah, my idea would be to find the fault that causes it to trip when water is poured on the stones in the sauna. This sounds like a definite link has been made between this action and tbe tripping of the RCD, so it needs to be investigated.

 

[pc1966]

Yeah, my idea would be to find the fault that causes it to trip when water is poured on the stones in the sauna. This sounds like a definite link has been made between this action and the tripping of the RCD, so it needs to be investigated.

Yes, a couple of things to find out, such as did it always do this? (i.e. is a 30mA trip too low for that sort of installation) or has something changed.

It might not be the actual sauna heater of course, it could be that a light in the sauna is letting steam in and causing the earth leak. Maybe someone put in a replacement without suitable IP ration, or maybe it has special seals around them that have degraded with time, etc.?

That is the problem with a single RCB and intermittent trip - they might find it is actually a light circuit or similar that is causing it to trip.

Maybe @Vinnie2020 can get them to run it and make it trip then quicky isolate all the MCBs and see if an insulation tests reveals a leaky circuit before it dries out.