UNUSUAL RCD SWITCH TRIP

[Johanna1]

My RCD switch trips at the most unsual times, it will trip at 3am (no electric items are plugged in bar the kitchen appliances) then i will reset it and it will trip again at 10pm the next evening. It also tripped at 7:15am this morning. Electricians have been out and tested all my sockets and ive unplugged my fridge and washing machine for a few hours to see was it them and the RCD still tripped. I have no clue what to do next. I asked them to test the appliances but they dont think this is necessary. What else can i do?

 

[brianmoooore]

You say "my RCD switch". Do you just have one RCD covering all circuits?
Pics. of your consumer unit/fusebox would be good.

 

[James]

You need spark that is good at fault finding
They should work methodically through the circuits and find the fault.

Likely suspects are
Floodlights, garden lights, any outdoor sockets.
Immersion heaters
Ovens electric hobs

 

[westward10]

Are 3am and 10pm common occurrences.

 

[brianmoooore]

You need spark that is good at fault finding
They should work methodically through the circuits and find the fault.

Likely suspects are
Floodlights, garden lights, any outdoor sockets.
Immersion heaters
Ovens electric hobs

I would hope that any sparks worthy of the title would have already considered all these, and presumably IR testing has thrown up nothing, meaning it is a true intermittent fault, rather than something occasionally tipping over the edge.
The weirdest one I ever found (after others had tried and failed) turned out to be caused by a chest freezer.
The lid had a light built into it which came on when it was opened.
Ice had built up in the lamp enclosure, which would melt from the heat of the lamp. When the lid was closed the liquid water would take about half an hour to reach some live terminals and trip the RCD. The water would then freeze again, and IR would read perfect.

 

[Johanna1]

You say "my RCD switch". Do you just have one RCD covering all circuits?
Pics. of your consumer unit/fusebox would be good.

 

[Johanna1]

its just the RCD switch that trips, none of the other fuses trip. Electricans have been here and they have tested sockets and the fuse board. They said all were fine. I dont know what else there is to do. The RCD just trips randomly for no reason. I dont know a lot about this but everything has been checked and the RCD still trips. I thought it was faulty wiring but i was told this wasnt the case either.

 

[brianmoooore]

First of all, no real electrician would leave that fuse box as it is in the pic. The missing blanks in the top row mean that it is regarded as "an immediate threat to life".
Is it just the bottom row that loses power, or is the top rom connected through the RCD as well?
What country are you in? The type of board you have is available in the UK, but would be very unusual.

 

[Johanna1]

You need spark that is good at fault finding
They should work methodically through the circuits and find the fault.

Likely suspects are
Floodlights, garden lights, any outdoor sockets.
Immersion heaters
Ovens electric hobs

I live in an apartment so i dont have any outside lighting/sockets to worry about. I suggested the electricans look at the cooker wiring and lighting but they just said the RCD doesnt control either of them. Also when the RCD trips the oven and lights still work so they ruled them out this morning. My immersion is never switched on because my water heats up from my heating system.
I suggested a PAT test on the electrical appliances in my kitchen. They're going to do that next week.

 

[Johanna1]

First of all, no real electrician would leave that fuse box as it is in the pic. The missing blanks in the top row mean that it is regarded as "an immediate threat to life".
Is it just the bottom row that loses power, or is the top rom connected through the RCD as well?
What country are you in? The type of board you have is available in the UK, but would be very unusual.

I live in Dublin. No fuses in the bottom row trip, the only one that trips is the RCD switch.

 

[Johanna1]

Are 3am and 10pm common occurrences.

no, the RCD just trips randomly. Its very unpredictable.

 

[westward10]

First of all, no real electrician would leave that fuse box as it is in the pic. The missing blanks in the top row mean that it is regarded as "an immediate threat to life".
Is it just the bottom row that loses power, or is the top rom connected through the RCD as well?
What country are you in? The type of board you have is available in the UK, but would be very unusual.

I don't think we really need the drama of a few blanks missing.

 

[brianmoooore]

So it's the socket and immersion heater circuits that the problem lies in.
You say you don't use the immersion heater, but it can still be the problem if it isn't isolated by a double pole switch, although this should have shown up with basic tests, if it were the problem.
The next DIY step you can take is to unplug everything from the sockets, not just switch them off, (although I don't know if Eire uses SP or DP s/sockets), and see if the tripping stops. Don't forget hidden sockets that might be behind appliances
I realise this will be difficult if you have a fridge and/or freezer. Does your cooker switch have a socket built into it? If so, try to run these two appliances from it on an extension lead.

 

[brianmoooore]

I don't think we really need the drama of a few blanks missing.

Really? I was slated a couple of days ago for not reporting similar to the HSE.
We have a situation here where the OP is regularly accessing the box, and as far as I knew at the time, could have been accessing it in the dark.
There's also the matter of what looks like an overloaded main switch and/or supply.

 

[westward10]

Really? I was slated a couple of days ago for not reporting similar to the HSE.
We have a situation here where the OP is regularly accessing the box, and as far as I knew at the time, could have been accessing it in the dark.

The issue here is the rcd tripping not a few missing blanks and the HSE.

 

[Johanna1]

So it's the socket and immersion heater circuits that the problem lies in.
You say you don't use the immersion heater, but it can still be the problem if it isn't isolated by a double pole switch, although this should have shown up with basic tests, if it were the problem.
The next DIY step you can take is to unplug everything from the sockets, not just switch them off, (although I don't know if Eire uses SP or DP s/sockets), and see if the tripping stops. Don't forget hidden sockets that might be behind appliances
I realise this will be difficult if you have a fridge and/or freezer. Does your cooker switch have a socket built into it? If so, try to run these two appliances from it on an extension lead.

I'm going to plug out everything tonight again, its unfortunate because if the RCD stayed down then the electricans would be able to pin point where the fault is but i just push it back up after it trips and it wont trip again for another few hours.
(I'm not sure about the cooker switch. Its just a standard large red switch on a white base)

 

[Johanna1]

Really? I was slated a couple of days ago for not reporting similar to the HSE.
We have a situation here where the OP is regularly accessing the box, and as far as I knew at the time, could have been accessing it in the dark.
There's also the matter of what looks like an overloaded main switch and/or supply.

im not sure its overloaded as all the fuses have been tested more than once this week and it all came back clear. None of the other fuses trip. Its just the RCD thats the nuisance. (The top row i never have a problem with)

 

[Wilko]

Hi- sorry to hear that your RCD is tripping. It does indicate there is a fault, either with the appliances, the wiring or the RCD itself. The good news is RCDs rarely fail and they can easily be tested with the right equipment.

its unfortunate because if the RCD stayed down then the electricans would be able to pin point where the fault is but i just push it back up after it trips and it wont trip again for another few hours.

Sorry to say but this is not correct, in my opinion. You resetting the RCD in the morning would not in any way affect or hinder me from finding the cause of the trip .

Perhaps have the Electrician verify the incoming earth to your property. It’s likely you have an earth provided to you and this needs to be in good shape. I have seen random tripping vanish when the DNO earth was improved.

 

[Johanna1]

You need spark that is good at fault finding
They should work methodically through the circuits and find the fault.

Likely suspects are
Floodlights, garden lights, any outdoor sockets.
Immersion heaters
Ovens electric hobs

can i just ask you, if i plug out all my plugs tonight (minus my washing machine and fridge) and if it trips in the middle of the night again does that mean the source of the trip is from my kitchen? It couldnt be from any where else if i have everything else plugged out in the other rooms could it? It wouldnt make sense.

 

[brianmoooore]

Everything you left unplugged could probably be eliminated from the enquiry, unless the problem is cumulative leakage from more than one source, but it could still be a problem with the actual wiring.
Unfortunately, washing machine especially, and fridge are two of the most likely candidates to be the problem.

 

[Johanna1]

Everything you left unplugged could probably be eliminated from the enquiry, unless the problem is cumulative leakage from more than one source, but it could still be a problem with the actual wiring.
Unfortunately, washing machine especially, and fridge are two of the most likely candidates to be the problem.

i was told it wasnt a leakage because everything came back clear from the tests they did. Hopefully when i plug out everything tonight nothing will trip and if i does ill know its defnitely the kitchen. Also, i dont want to run out and buy a new washing machine and fridge, id be afraid nothing would change with the tripping and id be out nearly 1400euro.

 

[Johanna1]

Hi- sorry to hear that your RCD is tripping. It does indicate there is a fault, either with the appliances, the wiring or the RCD itself. The good news is RCDs rarely fail and they can easily be tested with the right equipment.

Sorry to say but this is not correct, in my opinion. You resetting the RCD in the morning would not in any way affect or hinder me from finding the cause of the trip .

Perhaps have the Electrician verify the incoming earth to your property. It’s likely you have an earth provided to you and this needs to be in good shape. I have seen random tripping vanish when the DNO earth was improved.

the electricians did fairly extensive tests and they told me it came back all clear, they could just be saying that to shut me up though as i keep questioning if everything is truly clear then why does it keep tripping? Also the wiring in the fuse board is clear from some test i saw them do with a machine? (not sure what its called) and they replaced the RCD switch twice. It didnt make a difference because it still tripped when they left.

 

[Wilko]

they replaced the RCD switch twice. It didnt make a difference

Ha, makes me chuckle. I call that playing spare parts roulette .

 

[Johanna1]

Ha, makes me chuckle. I call that playing spare parts roulette .

i know, it didnt need to be replaced, it wasnt broken it was still tripping so it was doing what it was meant too. The electricans that come to my home arent great.

 

[brianmoooore]

the electricians did fairly extensive tests and they told me it came back all clear,

As did all the tests on the incident with the freezer I mentioned earlier in the thread. You likely have a true intermittent fault, rather than the normal case where a fault exists, that is easily detected with the right equipment, but occasionally trips the RCD as a result of a surge or cumulative leakage from more than one source.
I totally agree with your electricians trying a new RCD once. There was a MEM RCD many years ago that would go faulty and trip out occasionally for no genuine reason. Changed several with no other fault present.
If it's still tripping with most things unplugged, the next step I would take is to fit a temporary s/socket beside the fusebox, protected by its own RCD and MCB, and plug your fridge and washing machine into them in turn, using an adequately rated extension lead.

 

[Darkwood]

You say you do not use the immersion heater, let's assume then you have a combi boiler, if this is spurred off that affected circuits then it could be a pump or the boiler itself breaking down and leaking to earth, I would do a visual check in and around the boiler to see if there are any leaks. Under test conditions from the Electricians it could be the case the system isn't running/calling for heat so may not be detected.
Other causes of intermittent tripping is often external equipment that has a degraded IP rating and will only be an issue if the weather conditions are suited. (log the tripping times and the weather to see if there is a correlation)

I would expect both are things an experienced electrician would consider but like any job it is often the case that a fault that an electrician may have never experienced before may not be considered and thus overlooked.

 

[Johanna1]

Everything you left unplugged could probably be eliminated from the enquiry, unless the problem is cumulative leakage from more than one source, but it could still be a problem with the actual wiring.
Unfortunately, washing machine especially, and fridge are two of the most likely candidates to be the prob

You say you do not use the immersion heater, let's assume then you have a combi boiler, if this is spurred off that affected circuits then it could be a pump or the boiler itself breaking down and leaking to earth, I would do a visual check in and around the boiler to see if there are any leaks. Under test conditions from the Electricians it could be the case the system isn't running/calling for heat so may not be detected.
Other causes of intermittent tripping is often external equipment that has a degraded IP rating and will only be an issue if the weather conditions are suited. (log the tripping times and the weather to see if there is a correlation)

I would expect both are things an experienced electrician would consider but like any job it is often the case that a fault that an electrician may have never experienced before may not be considered and thus overlooked.

my gas boiler heats up my water, there is no need for the immersion to be turned on. The electricans tested all the fuses in the fuse board and replaced the RCD all working fine. I plug out everything at night, except obvious appliances like the washing machine and fridge. It didnt trip last night, which was unusual as im so used to it tripping so often. I had my sockets replaced from metal to plastic so that might be the reason but i doubt it.

 

[brianmoooore]

As I've said earlier, the immersion, or any other appliance does not need to be turned on to cause problems, if it is switched 'off' by interrupting the live wire only. Both single pole and double pole switches are available in GB, but I don't know what's used in Eire.
If it didn't trip with appliances unplugged, leave them disconnected for a few days when not needed and see if the RCD continues to misbehave. If it does, plug everything back in again, and see if the problem starts again. If it does, repeat the whole experiment again.
If this confirms that an appliance is the problem, repeat the experiment again with only half of the plugs disconnected, and eventually you'll nail the culprit.
It may take weeks, but it's free.

 

[Johanna1]

As I've said earlier, the immersion, or any other appliance does not need to be turned on to cause problems, if it is switched 'off' by interrupting the live wire only. Both single pole and double pole switches are available in GB, but I don't know what's used in Eire.
If it didn't trip with appliances unplugged, leave them disconnected for a few days when not needed and see if the RCD continues to misbehave. If it does, plug everything back in again, and see if the problem starts again. If it does, repeat the whole experiment again.
If this confirms that an appliance is the problem, repeat the experiment again with only half of the plugs disconnected, and eventually you'll nail the culprit.
It may take weeks, but it's free.

Thankyou for your advice. After hours of figuring it out and keeping my appliances out for 24 hours we worked out that it was the fridge causing the problem. A bit annoying as it was only 2 years old but i was advised to buy a new one.