Intermittent Tripping

[MarcMCFC1986]

Hello

I've attached a photo of the Consumer Unit. The switch on the far left is what keeps tripping off, which turns off all the power except the two lights circuits - they are controlled by the Main Switch on the far right. The three switches that are down aren't connected to anything.

When I got in from work on Friday the far left switch was off - and so all the power was off (expect the lights). I flipped it back up and it held, until Saturday night at about 10pm - when I was just sat on the sofa with the TV on, nothing else was switched on in the house (except the fridge, freezer, and internet router). I flipped the far left switch again and it tripped off about 3 times in a row - so I left it for half an hour, flipped it again, and it held until 3am this morning (so, 77 hours later roughly) - I noticed when I got up to go to the toilet. Again, I flipped the switch and it tripped off straight away, so I turned off the MCB for the shower and the far left switch tripped off, then I tried the Kitchen Sockets, then flipped the far left switch again and it held - so I left the kitchen sockets off. This morning I got up, flipped the Kitchen Sockets MCB back on and it it still on now.

So, I've narrowed it down to the kitchen, but feel like I need to sit around and wait for it to go off again so I work out specifically what it is in the kitchen which is causing the problem (I didn't really fancy doing it at 3am). My suspicion is the Fridge or Freezer as they were the only things that were left on whilst at work on Friday, whilst sitting on the sofa on Saturday night, and overnight last night.

I'm a novice at all this - only been a home owner two years - so not sure what the next step is? I've just ordered this on Amazon (https://www.amazon.co.uk/gp/product/B000RZDNZM/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1) so I can plug the fridge in, then the freezer, and see which (if any) trips the circuit.

Any other ideas? Advice? Trying to save the cost of calling out an Electrician to do things that I could do myself, but also don't want to take any risks!

Don't want to sound like a soft-arse, but I get really worried and anxious about these kinds of things, as I quite simply don't have the money to get any major repairs or work done. I've saved up and put to one side a few hundred quid for emergency call outs/replacement items but beyond that I've got nothing really - bought the house two years ago so all my savings went on the deposit for here, and now saving up for a my wedding so any spare money I have now goes into that savings pot!

Thank you in advance for any advice.

 

[terryplumb]

You are wasting money buying that. The RCD that is tripping needs investigation by an electrician to establish the cause.

 

[MarcMCFC1986]

You are wasting money buying that. The RCD that is tripping needs investigation by an electrician to establish the cause.

I agree. But I phoned a very reputable electrician this morning and reckons the investigating work I've done so far is exactly what he would do - and based on what I've said he's sure it is the fridge or freezer, so doesn't want to charge me £60 to come out and repeat what I've done and tell me what I already know. Recommended contacting a domestic appliance repair company to come and check the fridge & freezer.

 

[winston1]

You are wasting money buying that.

As you are so skint send it back under the distance selling regulations.

 

[terryplumb]

Have you have provided the electrician with information other than you have given above ,which is totally inconclusive ? The RCD is tripping randomly / intermittently. Once held for 70 odd hours ,and after you switched off the kitchen MCB held for a much less period of time ,only several hours. Its quite possible that fridge / freezer may be the cause ,but that's a shot in the dark ,it could just as easily be on another circuit , amongst other things.Calling in an appliance engineer and paying them to check a specific appliance isn't particularly good advice ,if it turns out not to be appliance related .you should spend your money on an electricians time.
One of the mcb' s is marked water heater. Is that the immersion heater circuit ,and are you heating your domestic hot water currently with it ?

 

[jj4091]

Do you have a long extension lead that you can plug into one of the sockets that are not in the kitchen then switch off the mcb that controls the kitchen sockets & then connect the fridge & freezer into the extension lead. If it still trips that confirms it is either the fridge or the freezer. You would then need to move the food from the freezer into the fridge & leave the freezer switched off. If it still trips then try the same thing with the fridge.

 

[MarcMCFC1986]

Have you have provided the electrician with information other than you have given above ,which is totally inconclusive ? The RCD is tripping randomly / intermittently. Once held for 70 odd hours ,and after you switched off the kitchen MCB held for a much less period of time ,only several hours. Its quite possible that fridge / freezer may be the cause ,but that's a shot in the dark ,it could just as easily be on another circuit , amongst other things.Calling in an appliance engineer and paying them to check a specific appliance isn't particularly good advice ,if it turns out not to be appliance related .you should spend your money on an electricians time.
One of the mcb' s is marked water heater. Is that the immersion heater circuit ,and are you heating your domestic hot water currently with it ?

Maybe I didn't explain clearly, as I typed quickly before coming to work.

The RCD held for 70 odd hours with everything (all MCB's) switched on - then tripped off last night. I switched it back on, but it tripped straight off again. However, when I switched off the Kitchen MCB then switched on the RCD, the RCD stayed on - so he suggested that it would be something on the Kitchen Circuit which is causing the RCD to trip, and the only things actually doing anything at the times it has tripped is the fridge & freezer.

 

[bernardgreen]

An RCD can be tripped by a fault between Neutral and Earth on a circuit even if the MCB for that circuit is switched OFF. The RCD trips when an appliance on another circuit switches ON which leads one to believe that the fault is in that appliance. Not all electricians are aware of this.

When looking for the cause of random tripping of an RCD the electrician should first check all circuits in the house for Neutral to Earth faults

 

[MarcMCFC1986]

Do you have a long extension lead that you can plug into one of the sockets that are not in the kitchen then switch off the mcb that controls the kitchen sockets & then connect the fridge & freezer into the extension lead. If it still trips that confirms it is either the fridge or the freezer. You would then need to move the food from the freezer into the fridge & leave the freezer switched off. If it still trips then try the same thing with the fridge.

Thanks - Yes this is something we're also thinking of trying. We do have a spare fridge & freezer in the garage that we just switch on when we're having parties to store food, drinks, and ice cubes in - so we'll probably drag those into the house tonight and store the food in them for a week or so, while the usual fridge/freezer are being tested on the other circuit!

 

[winston1]

and the only things actually doing anything at the times it has tripped is the fridge & freezer.

But was anything else plugged in and switched off? Most switches only switch the live (including MCBs in the CU) and neutral faults can cause the RCD to trip.

EDIT too slow.

 

[terryplumb]

I understood perfectly Marc. Please appreciate that earlier in your post you told us that re setting the RCD ,with all mcbs ON ,allowed the RCD to re set. So its intermittently tripping. You put the kitchen MCB back on ,and the RCD didn't trip...totally inconclusive.

 

[MarcMCFC1986]

But was anything else plugged in and switched off? Most switches only switch the live (including MCBs in the CU) and neutral faults can cause the RCD to trip.

EDIT too slow.

Yes, in the kitchen the kettle, toaster, microwave and radio were all plugged in - but not doing anything at the time.

An RCD can be tripped by a fault between Neutral and Earth on a circuit even if the MCB for that circuit is switched OFF. The RCD trips when an appliance on another circuit switches ON which leads one to believe that the fault is in that appliance. Not all electricians are aware of this.

View attachment 168723

When looking for the cause of random tripping of an RCD the electrician should first check all circuits in the house for Neutral to Earth faults

This is mind boggling for a novice like me, but interesting to know. However, when you say "The RCD trips when an appliance on another circuit switches ON" - there was nothing on another circuit switching on at the time. Only thing we have on a timer that automatically switches on/off is the pond pump - but that is 8am - 5pm. The times the RCD has been tripping is during the day whilst at work on Friday, Saturday 10pm-ish, and around 3am last night?

 

[bernardgreen]

This is mind boggling for a novice like me,

Don't worry, I have found it to be totally mind boggling for some "electricians" ( those who can install but not diagnose faults )

 

[MarcMCFC1986]

One of the mcb' s is marked water heater. Is that the immersion heater circuit ,and are you heating your domestic hot water currently with it ?

Only just noticed this bit. I have combi-boiler now, so I assume it is that which is connected to this MCB.

I understood perfectly Marc. Please appreciate that earlier in your post you told us that re setting the RCD ,with all mcbs ON ,allowed the RCD to re set. So its intermittently tripping. You put the kitchen MCB back on ,and the RCD didn't trip...totally inconclusive.

I know - I never said it was conclusive, hence why I'm here asking what to do next. You said to call an electrician, I did that and he said I've already done everything he would do anyway.

I guess I could call a couple more and see if they suggest anything different.

 

[jj4091]

It seems you have a supply to your garage but there does not appear to be an separate mcb supplying the garage. Is it possible it is fed from the kitchen socket circuit & if so is there a junction box on an outside wall anywhere between the kitchen & garage? Damp in an external junction box is a much more likely cause of intermittent tripping of an rcd.