Discuss Smart Meter Tripping RCD in the Electrical Forum area at ElectriciansForums.net

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Thought I would throw my tenant's problem regards Smart Meters (SM) into the mix, in the hope someone could maybe suggest what is going on?

May 2016 - tenants switch to E.org - no problem.
March 2017 - had Liberty 100 PAYG SM (top-Up via App) installed and immediately the RCD/fusebox starts tripping intermittently - every few hours, every day, after few days - see picture.
April 2017 - I contacted E.org and they stated that SM not cause switches to trip, fault is fusebox. Accept what they say.

Tripping continues and tenants check and monitor if appliances causing problem. None found.
BG electricians check home electrics 4 times and state domestic side and RCD all ok - Dec 2017, Aug 2018, Sept 2018 and Oct 2018.

After much elimination find Cause???!!!
Customer Top Up - when tenant tops up via app and then a few minutes later credit shows up on phone, then RCD immediately trips.
Supplier reading - after informing E.org about above and they do On Demand reading from their end, then RCD immediately trips.

E.org change SM Oct 2018 and tripping now worse.
BG check after SM change and state domestic side and RCD all ok.
E.org state that fault is RCD as have changed SM and thus are insistent they are not at fault.
BG believe it is SM, so I am between a rock and hard place.
Requested E.org replace SM with Dumb Meters as a way of eliminating or confirming SM is cause of tripping, but will only do if I pay.

Now starting case with Energy Ombudsman… And tenants’ life not good as now 3/4 times a day have to reset RCD.
Any ideas/advice?

Liberty 100 SM next to RCD.jpeg
 
D

Deleted member 26818

Theoretically, there should be reason that the meter can cause a downstream RCD to trip.
 
Marvo

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Probably not the kind of advice I should be posting on the publicly viewable forum but I'd either relocate the meter a greater distance from the CU or I'd wrap the CU in thick tin foil with a bonding wire attached to it and see if the nuisance tripping stops. Obviously isolate, and do a risk assessment first etc.

Smart meters can have fairly powerful WAN transmitters and even GSM transmitters which could cause issues with RCD's if in very close proximity.
 
J
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the only way to cause an imbalance on a downstream RCD is to cause a leak from one of its outgoing live conductors. Even if there is a neutral-earth fault downstream, there would still be no leak as long as there is no potential difference between earth and neutral.
If the smart meter could cause a change the potential on the neutral above earth, it would cause an imbalance in the presence of a N-E fault.
Has someone actually IR tested the neutral bar with main switch off to the MET with the main earth and all bonding and cpcs connected?
 
O

Octopus

the only way to cause an imbalance on a downstream RCD is to cause a leak from one of its outgoing live conductors. Even if there is a neutral-earth fault downstream, there would still be no leak as long as there is no potential difference between earth and neutral.
If the smart meter could cause a change the potential on the neutral above earth, it would cause an imbalance in the presence of a N-E fault.
Has someone actually IR tested the neutral bar with main switch off to the MET with the main earth and all bonding and cpcs connected?

I’ve given you a disagree because lose connections on the supply side can and do trip rcds
 
OP
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Will request tenant send me pic with fuseboard cover open. And reason taken so long from initial problem starting immediately when change to SM in March 2017 and going to Energy Ombudsman now is that we also could not believe top up cause RCD trip - but it is true! Also, please see below BG report picture from 11 Oct 2018.

elecforum BGReport.jpg
 
J
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I’ve given you a disagree because lose connections on the supply side can and do trip rcds
Agree completely, that's why I said "cause an imbalance" because I know there are other ways to trip an RCD.
I just wanted to get the obvious question about whether it was tested properly out of the way!
Given the BG guy has written "power trips out" which is useless without saying what trips (presumably the RCD), I wouldn't be sure they had an eye for precision.
 
PEG

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This is a situation crying out for more in-depth testing,including data logging,etc.
I hold minimal faith,in BG being capable of delivering this...
 
OP
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I have asked E.org what the mobile phone signal strength is when they installed the 1st and 2nd SM. The house is in a poor signal area. Would the need to boost the signal from the SM cause interference in the CU?
Will get tenant to take pic when next trip.
 
OP
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This is a situation crying out for more in-depth testing,including data logging,etc.
I hold minimal faith,in BG being capable of delivering this...
4 electrical checks - 3 by BG, last one by PH Jones.
What exactly regarding in depth checks are needed, so I can request these be made.
I feel responsible for tenant, as not fair they are living with RCD tripping constantly, and who knows how long Energy Ombudsman get to resolution, 8 weeks, after xmas!
 
Strima

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As far as I know, mobile modems vary their signal strength based on the strength of the signal they receive, so if the signal is weak, they'll increase their output accordingly.
Yup, the weaker the signal the more power the send out trying to get good comms with the local mast.
 
TJ Anderson

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Even if there is a neutral-earth fault downstream, there would still be no leak as long as there is no potential difference between earth and neutral.

If there was a neutral earth fault downstream e.g. shorted together then there would indeed be no PD but there would be earth leakage, it will parrallel the neutral return current through the cpc. If RCD protected then that would trip from the L-N inbalance
 
TJ Anderson

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4 electrical checks - 3 by BG, last one by PH Jones.
What exactly regarding in depth checks are needed, so I can request these be made.
I feel responsible for tenant, as not fair they are living with RCD tripping constantly, and who knows how long Energy Ombudsman get to resolution, 8 weeks, after xmas!

To be fair, I think the BG spark has done what he can. He has taken Zs to prove effective connection to earth. He has taken IR at 250vdc. He likely selected 250vdc so he could test with loads connected to eliminate both wiring and loads for earth faults. Sensible. He has also ramp tested RCD.

I agree with others that it may well be interference from meter comms mobile being so close to RCD. IIRC the RCD in that board will be an MEM with a functional earth wire it may act like an antennae!
 
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Wilko

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Hi - From afar I guess we can never solve this, but there are couple more things for an Electrician to look at in my view. Did the BG Electrician actually personally observe the remote test and the tripping RCD? I would be seeking cooperation from the meter company with some more testing. Something like : Standing at the box with main switch, RCD and all circuits on, have the remote test done and observe the RCD trip. Reset RCD and turn all MCBs off and repeat the remote test and observe any trip. Safely remove the outgoing N from the RCD (still leaving all MCBs off) and repeat the remote test and observe any trip.
 
Leesparkykent

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I remember a thread on here a few years ago where on a site walkie talkies were the cause of RCBO’s tripping. And I think it was the same thread where @GMES had the same or knew someone who had the same issue with over 300 RCD sockets and walkie talkies.
 
Strima

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You need to find someone with an electromagnetic radiation tester to see what the meter output is.
 

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