Tripping rcd

[JohnW2]

I think the frequancy may be a red herring, ...

Indeed. In fact, if there were a theoretical need for a Type F RCD (which I somewhat doubt), then I thought that the potential problem with not having one would be that the RCD might not trip when it should, rather than it tripping when it shouldn't?

one looks at other things first, the insulation tester and clamp on ammeter are the first tools. ... However he says an electrician has been employed, so one assumes run of mill tests already done, so assuming no fault found, one then has to look at more unusual causes.

All probably true.

Kind Regards, John

 

[wull67]

Thanks for all your input guys, the fault turned out to be the lmmersion/element, even though it wasn’t being used, suspected earth leakage going through the neutral, during fault finding if he disconnected the earth on the immersion the fault still happened but when he disconnected the neutral and earth the fault disappeared, put new immersion in and all good.
As I said I’m not a sparky so don’t understand why and how but that was the solution, thanks

 

[Deleted member 267285]

Thanks for letting us know the fault @wull67 good to know outcomes

 

[bernardgreen]

This is why an RCD will trip on an Neutral to Earth fault when the faulty circuit is not switched on but something else is taking current.

 

[wull67]

Would the above do it without load?? The immersion wasn’t being used and also isolated by a circuit breaker inside the appliance??

 

[bernardgreen]

Would the above do it without load

There has to be a load somewhere to cause a current to flow.

if he disconnected the earth on the immersion the fault still happened

The Earth would still be connected to the immersion heater via the pipes and bonding of the water pipes

 

[bernardgreen]

and also isolated by a circuit breaker inside the appliance

It would have to be a double pole breaker to isolate both Live and Neutral from the fault.