Strange issue - Who can solve my 'tripping' challenge?

[gingerrubix]

Hey all, I'm looking for some advice to help me troubleshoot my strange issue with my consumer unit/fuse board on which my RCD keeps tripping.

Disclaimer - I'm a DIYer. I have an electrician involved and I'm 100% planning on leaving the work to the pro(s). However, He's not had time to do any real testing just yet, so I thought I'd get the ball rolling as he's said it might be a nightmare to solve.

So, I have an empty property that my recent tenants have moved out of. Near the end of their tenancy, they were reporting that the electricity was tripping throughout the night.

The consumer unit only has one RCD which protects breakers for downstairs sockets, upstairs sockets, the cooker and a single socket that sits next to the unit.

When they moved out I thought it'd be a simple process to isolate the issue (how wrong I was ha ha)

I thought it would be an appliance/device plugged in somewhere but even with EVERYTHING unplugged including the cooker, extractor fan, fridge-freezer, even the boiler, but it still trips… even if ALL the MCBs are switched to OFF.

But, it doesn't trip immediately, it doesn't trip during the day either.

This is where it gets weird…..

It seems to be tripping at the exact time each night, at 00:53 (or at least 3 out of the 4 times I've accurately timed it - the other time was close at 00:15). It doesn't make sense!

I believe that this type of tripping issue could be down to water ingress, I thought I may have found a candidate in a socket that was in a chimney breast that was always getting soaked/prone to leaking, but the electrician, removed that socket and made it safe (connecting the wires) but it still tripping and besides…..if it was water ingress, why would it trip at exactly the same time of night 3 times in a row?

One thing I haven't been able to test so far (because I'm not living at the property) is if it would continue to trip later in the evening, if I reset it. At the moment, I'm going round to the property every morning and finding it tripped.

Could it be a problem with the consumer unit itself?

This seems like a proper head-scratcher to me so hoping the combined brain of all you helpful/experienced lot may be able to point us in the right direction.

Happy to share pics if you need them.

Thanks in advance

Ginge

Extra info - that may or may not be related.
Bit of background on the things the tenant did.

• Running cat5 around the house (meaning getting under the floorboards where electric wires run quite loosely)#
• Changing light fittings (some not fitted to the ceiling properly/safely)
• Changing light switches (swapping for touch sensors etc)
• Disconnected the alarm panel - to replace with a touchscreen system that I think controlled the heating/lights, etc. I think this would have triggered the tamper on the alarm so they pulled a fuse from the main alarm panel to disconnect.
• He was also charging his electric car by feeding a cable from inside the house through the letterbox, out onto the road.
• He has changed a double socket in the hallway - not sure why but this would be the closest socket for him to charge his car.

Also, I have an old boiler that's just turned a fault after they moved out but it still powers up fine (being replaced in the next few days)
During the tenancy they have had the meter changed. But based on the label from the energy company EON, this was back in January 2023 - so over a year ago.
There have been recent reports of rats being seen on the street - I did consider that could have been a cause but again…. Why is it tripping at the same time each night?

 

[snowhead]

But I find it hard to imagine that the regular cellular system would able to do that otherwise it'd be widespread and very much a known thing.

It is a very well known thing.

There have been several similar ones over the years posted on here, originally Energy supplies wouldn't accept it was a fault, but if you search MEM RCD and "Smart" Meter fault you'll see some suppliers now remove the meter and replace with old type.

(P.S, you don't need the apostrophes on smart, that's just me refusing to accept something that's actually dumb and only responds to set oinstructions / commands being called smart)

 

[mainline]

I appreciate that @mainline, but as it's been consistently tripping at exactly the same time each evening, if shoving an RF barrier between the two devices prevents it tripping then surely it points towards that theory of the smart meter triggering it.
Of course, from there we'd then redirect the focus to the suitability of the RCD/Consumer unit/smart meter.

It could very well be the smart meter but, If you have a fault that's causing high earth leakage, say 5ma below the trip threshold then yes you could very well cure the timed tripping by shielding the meter, but you still wouldn't know if you also have a fault with the installation.
Personally, I would check the installation first, but that's just me

 

[timhoward]

My only other observation is that PRS legislation requires the installation to be inspected in rented properties and according to the sticker on the board it's overdue anyway. So getting it tested will kill two birds with one stone.
It tends to be older consumer units that have the smart meter proximity problem, and the Square D issue is fairly well known. Changing the consumer unit to a modern RCBO unit has a number of benefits (not least that the RCD 'trip' is per circuit not for the whole lot, so you don't lose everything in a fault).

 

[baldelectrician]

I have had conversations with smart meter installers and MEM RCD's have came up

It is a known issue.

If you call the supplier you can ask them to poll the meter while on the call and see if it trips

They could also send a signal to the meter to put it in to dumb mode (no communications)

Require them to either move the meter or replace the meter with a dumb one

 

[Vortigern]

Slight aside but vaguely of interest/relevance. I installed an emergency/microwave sensor light in hallway 1m from a smart meter. Customer complained of the light switching on and off all night. Various tweaks resolved it was the smart meter. So there is definitely a strong EMI field coming from them. Had to ditch sensor light

 

[Vortigern]

I guess the heater circuit is to a boiler? If so that could easily be the cause as the heating element my be breaking down. It may switch on at night??? Also have you considered switch each circuit off one by one for the night and narrowing down the tripping?

 

[pc1966]

There have been several similar ones over the years posted on here, originally Energy supplies wouldn't accept it was a fault

They would simply point out that the old RCD do not meet the EMC immunity specifications that came in around 1996, and so it is really the "fault" of the RCD to be too sensitive to RF, though at the time they were originally made there were few radio transmitters around, and certainly nobody expected one to be permanently located under a metre from the CU!

TL;DR the best option is to replace the CU, both the metal box of the new CU and the use of RCBO (that are now much more immune to RF as they have to be), is going to solve that problem and make future faults less troublesome and easier to trace.

Before that, of course, some systematic IR testing is not a bad idea, but the common time of tripping does point to something timed such as daily reporting of readings, etc.

 

[gingerrubix]

Bit of an update for you. I first tried creating a shield with some tinfoil wrapped round some cardboard and placing that between the two, but it tripped. I wasn't 100% convinced that it shielded it completely so the next day I just wrapped the meter instead. It's not tripped for 2 days!!!

Also, before I wrapped it, I rang the energy company (that my tenants were with) and whilst I was on the phone to the guy with my head in and out of the cupboard where the boxes are, it must have tripped 6 times. I asked if he was making updates to the meter at the time but he said he wasn't.

Anyway, after not believing what I said he must have done a bit of research and agreed that these concerns had been raised in the past and so he raised a complaint for me. He said that I should expect a phone call to potentially arrange a visit from a field engineer (or whatever it was called). I'll wait and see on that.

That suggestion to get the supplier to poll it whilst in on the call may be a good shout too.

One thing that could be related (or not) is that they tenant took the little tablet/screen that's supposed to tell the customer about how much energy is being consumed - wonder if a poll to that device is happening/failing.

So, I do think a new RCBO is the way forward though and agree that it's worth checking to see if there is a fault causing high earth leakage. I just hope that the energy company recognise it's an incompatibility caused by them swapping it out and offer to change it back to a dumb meter (which I was quoted approx 470 quid to do both elect/gas meters)

 

[pc1966]

Bit of an update for you. I first tried creating a shield with some tinfoil wrapped round some cardboard and placing that between the two, but it tripped. I wasn't 100% convinced that it shielded it completely so the next day I just wrapped the meter instead. It's not tripped for 2 days!!!

That makes me very nervous if any foil could wriggle its way in beside the cables!

So, I do think a new RCBO is the way forward though and agree that it's worth checking to see if there is a fault causing high earth leakage. I just hope that the energy company recognise it's an incompatibility caused by them swapping it out and offer to change it back to a dumb meter (which I was quoted approx 470 quid to do both elect/gas meters)

They certainly won't swap meters for free given it is not really the meter's fault (i.e. today those old RCD would fail the EMC immunity standards).

Really that £470 is best spent on a new CU!

 

[baldelectrician]

Bit of an update for you. I first tried creating a shield with some tinfoil wrapped round some cardboard and placing that between the two, but it tripped. I wasn't 100% convinced that it shielded it completely so the next day I just wrapped the meter instead. It's not tripped for 2 days!!!
View attachment 113736

Also, before I wrapped it, I rang the energy company (that my tenants were with) and whilst I was on the phone to the guy with my head in and out of the cupboard where the boxes are, it must have tripped 6 times. I asked if he was making updates to the meter at the time but he said he wasn't.

Anyway, after not believing what I said he must have done a bit of research and agreed that these concerns had been raised in the past and so he raised a complaint for me. He said that I should expect a phone call to potentially arrange a visit from a field engineer (or whatever it was called). I'll wait and see on that.

That suggestion to get the supplier to poll it whilst in on the call may be a good shout too.

One thing that could be related (or not) is that they tenant took the little tablet/screen that's supposed to tell the customer about how much energy is being consumed - wonder if a poll to that device is happening/failing.

So, I do think a new RCBO is the way forward though and agree that it's worth checking to see if there is a fault causing high earth leakage. I just hope that the energy company recognise it's an incompatibility caused by them swapping it out and offer to change it back to a dumb meter (which I was quoted approx 470 quid to do both elect/gas meters)

It's only the electric meter that has the commication hub, the gas meter will go in to dumb mode if the electric one is taken away.

Some suppliers also allow a property owner to buy a standard meter that meets UK / EU standards and they will fit it and seal them

 

[Penguin]

Hey all, I'm looking for some advice to help me troubleshoot my strange issue with my consumer unit/fuse board on which my RCD keeps tripping.

Disclaimer - I'm a DIYer. I have an electrician involved and I'm 100% planning on leaving the work to the pro(s). However, He's not had time to do any real testing just yet, so I thought I'd get the ball rolling as he's said it might be a nightmare to solve.

So, I have an empty property that my recent tenants have moved out of. Near the end of their tenancy, they were reporting that the electricity was tripping throughout the night.

The consumer unit only has one RCD which protects breakers for downstairs sockets, upstairs sockets, the cooker and a single socket that sits next to the unit.

When they moved out I thought it'd be a simple process to isolate the issue (how wrong I was ha ha)

I thought it would be an appliance/device plugged in somewhere but even with EVERYTHING unplugged including the cooker, extractor fan, fridge-freezer, even the boiler, but it still trips… even if ALL the MCBs are switched to OFF.

But, it doesn't trip immediately, it doesn't trip during the day either.

This is where it gets weird…..

It seems to be tripping at the exact time each night, at 00:53 (or at least 3 out of the 4 times I've accurately timed it - the other time was close at 00:15). It doesn't make sense!

I believe that this type of tripping issue could be down to water ingress, I thought I may have found a candidate in a socket that was in a chimney breast that was always getting soaked/prone to leaking, but the electrician, removed that socket and made it safe (connecting the wires) but it still tripping and besides…..if it was water ingress, why would it trip at exactly the same time of night 3 times in a row?

One thing I haven't been able to test so far (because I'm not living at the property) is if it would continue to trip later in the evening, if I reset it. At the moment, I'm going round to the property every morning and finding it tripped.

Could it be a problem with the consumer unit itself?

This seems like a proper head-scratcher to me so hoping the combined brain of all you helpful/experienced lot may be able to point us in the right direction.

Happy to share pics if you need them.

Thanks in advance

Ginge

Extra info - that may or may not be related.
Bit of background on the things the tenant did.

• Running cat5 around the house (meaning getting under the floorboards where electric wires run quite loosely)#
• Changing light fittings (some not fitted to the ceiling properly/safely)
• Changing light switches (swapping for touch sensors etc)
• Disconnected the alarm panel - to replace with a touchscreen system that I think controlled the heating/lights, etc. I think this would have triggered the tamper on the alarm so they pulled a fuse from the main alarm panel to disconnect.
• He was also charging his electric car by feeding a cable from inside the house through the letterbox, out onto the road.
• He has changed a double socket in the hallway - not sure why but this would be the closest socket for him to charge his car.

Also, I have an old boiler that's just turned a fault after they moved out but it still powers up fine (being replaced in the next few days)
During the tenancy they have had the meter changed. But based on the label from the energy company EON, this was back in January 2023 - so over a year ago.
There have been recent reports of rats being seen on the street - I did consider that could have been a cause but again…. Why is it tripping at the same time each night?

Hi Gingerrubix,
The fact that your previous Tenant replaced a faulty socket plate which he used for an external EV, raises an eyebrow.

Also your short dates between inspections, even though this is classed as Commercial as your a Landlord.

I’ve had a similar issue with a client where the Nuisance Tripping was always at night within a 10min period.
Even with the property empty, everything unplugged the boiler/fridge freezer isolated.

We eventually found that the semi-detached neighbour was stealing their electrical supply at night for a Cannabis growing set up in their loft.

Insulation resistance, R1-2 etc, Earth Leakage. Upgrade the board with the RCBOs (as a Landlord).

Check if your Service provider Meter is clocking up consumption with all the breakers off.

Good luck, let me know.