RCD trip

shibli

Hi

Hopefully someone with some electrical knowledge can help please, since my installation of the solar panels I am having issues with one of my appliances triggering the RCD when it draws significant electricity, the dishwasher after 30 mins triggers the RCD, no MCB is triggered. It's really strange as my whole house was rewired recently and the dishwasher is a year old and this has only occured since the solar installation. After resetting the RCD it's fine and the dishwasher continues with no issue. I am no expert but anyone can offer any advice please? Not sure who to call either the solar installers or an electrician who did the rewiring.

Martyn1981

Hi. I don't understand the following, hopefully someone can explain, but I understand there can be an issue with PV, especially in damp weather, if it's installed on a 30mA, rather than 100mA RCD.

I don't think this is a fault, just that it needs a bit more headroom, or it'll use up too much of the earth, possibly resulting in tripping.

Of course, this may have absolutely nothing to do with the problem you are getting, but perhaps an initial check to eliminate this reason?

shibli

Thanks, no rain here for weeks so weather has been dry and therefore no.damp, hopefully rains as grass needs it lol. Now sure if the RCD is 30 or 100. Do you think if that was increased it would be sufficient and safe ?

QrizB

This won't fix the earth leakage problem (if indeed there is one) but you could move the circuit with the PV - or the circuit with the dishwasher - to a dedicated RCBO rather than having it share the main house RCD.

2nd_time_buyer

Very strange but we have just started to have a similar problem the last couple of weeks.

Our RCD has been tripping early morning but not every day. It is the oven circuit that is tripping except that it still seems to be tripping even when the oven is switched off or even disconnected. It is making me wonder if it is something upstream as there is nothing else on the circuit. The only thing I can think is it is related to the inverter starting up in the morning. I am wondering if the solution might be too move the oven off the RCD or use a RCBO for that circuit. Or from what was said above perhaps the solar should be moved to a RCBO.

Solarchaser

If the rcd is tripping, its detecting current leaking to earth. Thats bad news generally,  but I'd suggest the best way to find out which is causing the issue is to buy an rcd plug
Like this:-
https://www.screwfix.com/p/masterplug-13a-fused-plug-through-active-rcd-adaptor/63731
And plug the washing machine into it before plugging the washing machine into a socket.
If this rcd trips, then its definitely the washing machine causing it.

However to be honest it's much more likely the solar inverter is causing it, solar inverters because of their switching can cause a bit of earth current and trip a 30ma rcd, which is why, as Martyn said above, its common to have that replaced with a 100ma rcd to avoid nuisance trips.

2nd_time_buyer  I'd think it's highly likely yours is your solar, so I'd be contacting the install company.

Both, if you take a picture of the rcd I can tell you which earth leakage its rated at.
But usually you would see for instance 100A 30ma on the trip switch

2nd_time_buyer

Thanks very much @Solarchaser . Actually I have just noticed that the solar is not on the RCD circuits. Should it be?

Could it still be tripping the RCD anyway?

shibli

Solarchaser said:

If the rcd is tripping, its detecting current leaking to earth. Thats bad news generally,  but I'd suggest the best way to find out which is causing the issue is to buy an rcd plug
Like this:-
https://www.screwfix.com/p/masterplug-13a-fused-plug-through-active-rcd-adaptor/63731
And plug the washing machine into it before plugging the washing machine into a socket.
If this rcd trips, then its definitely the washing machine causing it.

However to be honest it's much more likely the solar inverter is causing it, solar inverters because of their switching can cause a bit of earth current and trip a 30ma rcd, which is why, as Martyn said above, its common to have that replaced with a 100ma rcd to avoid nuisance trips.

2nd_time_buyer  I'd think it's highly likely yours is your solar, so I'd be contacting the install company.

Both, if you take a picture of the rcd I can tell you which earth leakage its rated at.
But usually you would see for instance 100A 30ma on the trip switch

Thanks so your suggesting the RCD should be swapped out for a 100A ? Fyi my consumer unit.

Solarchaser

The 0.03a is the 30ma rcd, but I agree, according to your diagram, the solar isn't on the rcd circuit,  though you would need to remove the front cover WITH MAINS OFF to be sure if it's on rcd or not

shibli

Should I contact the solar installers or just get my own electrician to replace the RCD?

Solarchaser

I think it may be easiest to switch off your solar (I know, I know) for a couple of days, if nothing trips, then I'd contact your solar installer.
If it still trips, then contact a spark