RCD trip

paul991

its always  best to have a separate rcd  for  each circuit but is more expensive .on a main switch rcd it could be a accumulation of earth leakage from different sources and your dish washer is just pushing it over the limit. You need to keep you sockets on a 30 ma rcd

70sbudgie

2nd_time_buyer said:

Solarchaser said:

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

Here is the inside @Solarchaser. To be honest, I have no idea what I am looking for. It looks quite "full". The solar is circled. Thanks for all the help, really appreciated.

I've lost track of which conversation is for which installation (cooker or dishwasher). But if this one is still a problem, My thoughts are:

The wiring isn't exactly the tidiest, so it is difficult to see what is going on. This could be contributing to the PV circuit inducing a small current in the earth wire - enough to trip the RCD. This would most likely occur in the morning when the sun goes above the PV horizon, as this would be when the PV makes the biggest step change in output and therefore induce the biggest current in a nearby circuit. Especially on a sunny day.

You would need a friendly electrician to tidy the wiring as it won't be a fun job! Intermittent faults are always the hardest to identify.

2nd_time_buyer

70sbudgie said:

2nd_time_buyer said:

Solarchaser said:

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

Here is the inside @Solarchaser. To be honest, I have no idea what I am looking for. It looks quite "full". The solar is circled. Thanks for all the help, really appreciated.

I've lost track of which conversation is for which installation (cooker or dishwasher). But if this one is still a problem, My thoughts are:

The wiring isn't exactly the tidiest, so it is difficult to see what is going on. This could be contributing to the PV circuit inducing a small current in the earth wire - enough to trip the RCD. This would most likely occur in the morning when the sun goes above the PV horizon, as this would be when the PV makes the biggest step change in output and therefore induce the biggest current in a nearby circuit. Especially on a sunny day.

You would need a friendly electrician to tidy the wiring as it won't be a fun job! Intermittent faults are always the hardest to identify.

@70sbudgie Thanks very much. Yes, this is the cooker. I probably should have started a new thread - apologies OP.

What you have said makes sense. One thing I am a bit confused about is the first time it tripped I was unable to reset the RCD until I switched off the cooker circuit. Does that fit in with what you said above?

Subsequently, I have been able to reset  the RCD without switching off any circuits. It hasn't tripped for a few days now. Intermittent faults are a PITA!

dil1976

2nd_time_buyer said:

3) replace the 30ma RCD with a 100ma RCD.

... Any other suggestions?

My gut feeling is that (3) would be easiest and most likely to solve the tripping problem. However, the electrician was sceptical on whether it was allowed to use a 100ma RCD. 

If you electrician is sceptical then its time to get rid of them as any decent electrician would know youy dont keep swapping things till it stops but you actually find the fault and reapir that. The RCD isnt tripping for fun but because there is something causing it too and that situation could be something more serious and potentially lead to harm or even death 

Solarchaser

dil1976 said:

Solarchaser said:

shibli said:

Solarchaser said:

shibli said:

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.

Sorry Shibli I missed your post.
You have a 63a rcd, this is standard, your main trip on right is 100a, again standard.
Your rcd is 30ma, so could be too sensitive as the solar is wired into this 30ma rcd circuit

Would you recommend removing the solar off the rcd ?

It would probably be easier to change the rcd to be honest.
You could shunt the box along and put solar right beside the main trip and before the rcd's, bit that's a fair undertaking, maybe an hour for a spark and alot more for DIY

Whereas changing out the rcd is pretty straightforward, 10 mins for someone reasonably competent with electrics
https://www.screwfix.com/p/british-general-fortress-80a-100ma-dp-type-ac-rcd/5948p

What would you swap the RCD for? it hasn't been proven to be defective so doesn't need swapping does it?

Nothing has been proven, however the OP is having nuisance trips,  and it's well known for solar inverters to cause nuisance trips with a 30ma rcd, and so changing it for a 100ma rcd would get rid of those nuisance trips if that's what happening.

Solarchaser

ispookie666 said:

@2nd_time_buyer if you have emergency backup power from your inverter you will need another source for earth. 
My knowledge on RCD trip is minimal other than having blamed victron for 6 months only to find the connected equipment was dodgy 🙈

I'm intrigued by this comment, your earth is essentially "your house only" and its there to get rid of any potentially harmful leakage and push it into the ground/ distribute it through everything to dissipate its wattage rather than give you a shock, so your whole house is on one earth, all your copper and metal in the house will be on it... or part of it is really more accurate, all your radiators, taps, electrical wire and it's unique to your house, I've never heard of anything where another earth is suggested, as it would in essence remove the effectiveness of the earth.
The only separate earth I've heard of is in relation to ev chargers and thats more an additional earth to ensure it can carry the full current of ev charging gone wrong. 

My eps uses the house earth, with no issue.

dil1976

Solarchaser said:

dil1976 said:

Solarchaser said:

shibli said:

Solarchaser said:

shibli said:

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.

Sorry Shibli I missed your post.
You have a 63a rcd, this is standard, your main trip on right is 100a, again standard.
Your rcd is 30ma, so could be too sensitive as the solar is wired into this 30ma rcd circuit

Would you recommend removing the solar off the rcd ?

It would probably be easier to change the rcd to be honest.
You could shunt the box along and put solar right beside the main trip and before the rcd's, bit that's a fair undertaking, maybe an hour for a spark and alot more for DIY

Whereas changing out the rcd is pretty straightforward, 10 mins for someone reasonably competent with electrics
https://www.screwfix.com/p/british-general-fortress-80a-100ma-dp-type-ac-rcd/5948p

What would you swap the RCD for? it hasn't been proven to be defective so doesn't need swapping does it?

Nothing has been proven, however the OP is having nuisance trips,  and it's well known for solar inverters to cause nuisance trips with a 30ma rcd, and so changing it for a 100ma rcd would get rid of those nuisance trips if that's what happening.

You cant just swap a RCD for a higher rated one if the way the cable is installed requires 30mA RCD protection then thats a no go straight away so they only thing you could do to negate that is rewire it in such away that means it wouldnt need RCD protection 

dil1976

Solarchaser said:

ispookie666 said:

@2nd_time_buyer if you have emergency backup power from your inverter you will need another source for earth. 
My knowledge on RCD trip is minimal other than having blamed victron for 6 months only to find the connected equipment was dodgy 🙈

I'm intrigued by this comment, your earth is essentially "your house only" and its there to get rid of any potentially harmful leakage and push it into the ground/ distribute it through everything to dissipate its wattage rather than give you a shock, so your whole house is on one earth, all your copper and metal in the house will be on it... or part of it is really more accurate, all your radiators, taps, electrical wire and it's unique to your house, I've never heard of anything where another earth is suggested, as it would in essence remove the effectiveness of the earth.
The only separate earth I've heard of is in relation to ev chargers and thats more an additional earth to ensure it can carry the full current of ev charging gone wrong. 

My eps uses the house earth, with no issue.

What absolute tosh you are talking here, please do yourself a favour and stop giving incorrect advice. Not every piece of metal work is connected to the main earth, for a start if the plumbing is all plastic that would stop the taps from being connected to it. 

2nd_time_buyer

dil1976 said:

Solarchaser said:

ispookie666 said:

@2nd_time_buyer if you have emergency backup power from your inverter you will need another source for earth. 
My knowledge on RCD trip is minimal other than having blamed victron for 6 months only to find the connected equipment was dodgy 🙈

I'm intrigued by this comment, your earth is essentially "your house only" and its there to get rid of any potentially harmful leakage and push it into the ground/ distribute it through everything to dissipate its wattage rather than give you a shock, so your whole house is on one earth, all your copper and metal in the house will be on it... or part of it is really more accurate, all your radiators, taps, electrical wire and it's unique to your house, I've never heard of anything where another earth is suggested, as it would in essence remove the effectiveness of the earth.
The only separate earth I've heard of is in relation to ev chargers and thats more an additional earth to ensure it can carry the full current of ev charging gone wrong. 

My eps uses the house earth, with no issue.

What absolute tosh you are talking here, please do yourself a favour and stop giving incorrect advice. Not every piece of metal work is connected to the main earth, for a start if the plumbing is all plastic that would stop the taps from being connected to it. 

That seems an unnecessarily confrontational reply

Solarchaser

2nd_time_buyer said:

Thanks again @Solarchaser. I have checked the earth, it doubles back on itself and is connected - the photo is just not very clear.

The electrician has done checks on the the cooker circuit (and the cooker) and hasn't found any faults. I guess it could be something else other than the solar on the RCD causing the cooker circuit to trip(?). I think he is a bit stumped now.

So it sounds like there are a few options.

1) Swap the cooker off the RCD with one of the other currently non-RCD circuits

2) as above but put the cooker on a RCDO so at least it doesn't trip all the circuits

3) replace the 30ma RCD with a 100ma RCD.

... Any other suggestions?

My gut feeling is that (3) would be easiest and most likely to solve the tripping problem. However, the electrician was sceptical on whether it was allowed to use a 100ma RCD. 

What do you think?

@QrizB yes those 2 circuits seem to be the loft circuit and one of the lighting circuits. I notice that the non RCD circuit on the far right is labelled "water heater". However, as we have a combi boiler I suspect this is an overhang when there was probably an immersion heater. So potentially I could ask the electrician to move the oven to there on a RCDO i.e. (2) above.

@ispookie666 the inverter does not have emergency backup. It is Solaredge. 

Thanks all. I am leaning a lot.

Good news indeed that its connected.

1 thing I was thinking is that in order to connect your solar to the earth bar, the solar guys may have had to move other earth's along the bar, and I guess I'd just be thinking to check all those screw connectors on the bar are tight, and there are no earth wires that are beside the earth bar, but not connected.... purely going on the fact it wasn't an issue until solar was connected.

I know you have said your spark has checked cooker and all is OK, but electric elements are always most likely to cause rcd faults, thinks like irons, washing machines, tumble dryers and cookers, and you can find that they only fault when the element itself gets to a certain temperature, so I'd perhaps advise seeing if you can make it trip, and if you find a way to make it trip, then keep doing it while switching off power to everything else on the rcd one by one until you can prove what it is.

There is definitely no issue with switching to a 100ma rcd, but if that's not the cause, then it will be a waste of money. (Edit. No issue for the inverter but sockets should really be on 30ma)

I personally would never move anything with an electric element off the rcd, it's main job is to stop you getting a shock.

Putting the cooker on its own RCBO could be a good idea, but then if the cooker is the issue then you will just get that RCBO tripping too.