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

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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.

1. The CU is in a daft place - and shouldn't really be in the meter cupboard
2. Would changing it to a AMD3 board help
3. Could the SM be disabled for a set period to see if the tripping stops?

Interesting thread..........
 
OP
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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.
@Wilko
Yes, BG actually observe top-ups causing trip.
Re: Remote Testing - E.org electrician change SM-tripping worse, but he could not touch CU/domestic side. So as per Wilko above, E.org electrician himself suggested that if I got an Electrician out that day, the two could work together - he work on the SM, while my man work on CU/domestic side. PH Jones electr1.ician comes and E.org electrician not contactable! PH Jones confirm 4th time, domestic side all ok.

@Murdoch
Re: On Demand test - yes, every time E.org did test while I on call with them, RCD trips
1. Yes, CU is in daft place
2. AMD3 board help - no idea as I am ignorant
3. I suggested replace SM with Dumb meters but E.org rejected idea, unless I pay cost. But, will ask Monday if they can remotely switch off SM and make it Dumb Top Up

Pictures below CU open
Only RCD - red middle switch trip
Also, tenant tells me today, that when trip happens - Plug circuit all off, But Light circuit stay on (lights work).
elecforum CU Red.jpg elecforum CU.jpg
 
marconi

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Ines Spires: Some thoughts:

1. Box in the area beneath the consumer unit and place some security seals so that it is obvious if anyone has attempted access.

2. Demand from the energy supplier confirmation that the anti-tamper features of the Secure Liberty 100 are working correctly and that the meter is not suffering from spurious tamper alerts. Are they receiving tamper alerts? Ask them what happens if a single tamper alert is reported to them; does it simply log the alert or is the supply shut off briefly and then restored. If there is a series of tamper alerts what happens?

3. Real tamper alerts are covered by (1) above.
 
Taylortwocities

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Also, tenant tells me today, that when trip happens - Plug circuit all off, But Light circuit stay on (lights work).
Of course. It’s only the sockets (to the left of the RCD) that are protected by the RCD.
The circuits to the right of the RCD do not have RCD protection. Don’t know why the labelling has been crossed out.
 
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Ines Spires: Some thoughts:

1. Box in the area beneath the consumer unit and place some security seals so that it is obvious if anyone has attempted access.

2. Demand from the energy supplier confirmation that the anti-tamper features of the Secure Liberty 100 are working correctly and that the meter is not suffering from spurious tamper alerts. Are they receiving tamper alerts? Ask them what happens if a single tamper alert is reported to them; does it simply log the alert or is the supply shut off briefly and then restored. If there is a series of tamper alerts what happens?

3. Real tamper alerts are covered by (1) above.

1. and 3. A second E.org electrician came after I demanded a Deadlock Letter. He did not change the new SM but did the following "removed the old anti tamper block and installed new 1 and 2 tails" as a free complimentary service. Not sure what that means. Picture below is before he did remove and install. elecforum Liberty 100 SM next to RCD.jpeg
 
marconi

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Ines Spires: Further thoughts for what you might ask the energy supplier.

1. Is the enclosure containing the consumer unit and meter made of metal? With the door (is it made of metal too?) shut the meter will/may have a difficult time transmitting and receiving signals, especially if the cellular network coverage is relatively poor at the property. Ask the energy supplier what the meter is programmed to do if there are no signals received from the meter or if the meter does not receive any signals for a 'prolonged' period? Ask this because inside the Liberty 100 is a big switch which is normally 'on' but can be turned off either remotely or by the computer inside the meter.

2. Find out what happens if the credit available in the meter runs out. Does the meter cut off or the supplier remotely cut off the electricity supply? What I am wondering is whether the App top ups are not being received by the meter (or intermittently) so the meter runs out of credit and turns off the supply which causes the RCD to trip. But you said the lights stay on - so maybe there is a brief turning off of the the supply until the new credit is loaded or there is a reserve amount of limited credit which kicks in sufficient to keep the electricity on a little while until the meter is topped up so folk are not plunged into darkness. If there is a problem with cellular reception and the meter is inside a metal box then it could be the tenants have paid for a top up but the meter only receives it when the enclosure door is opened to reset the trip.

3. Ask your tenants by how much they top up the meter - large or small amounts. Then consider (2) above.
 
Wilko

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... If there is a problem with cellular reception and the meter is inside a metal box then it could be the tenants have paid for a top up but the meter only receives it when the enclosure door is opened to reset the trip.
Monday morning brilliance !!!
Not to make fun of the hardships endured by folks because of this fault, but your thought did remind me of those silly slapstick films ...
 
SparkyChick

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That particular meter (or at least the one Big Clive took apart) has a facility on the modem for an external antenna. Maybe they could provide one that could be sited away from the consumer unit and disconnect the internal one.

Would be a relatively straightforward way to establish whether it's the close proximity of what is essentially a mobile phone to the RCD that's causing the issue.
 
Lucien Nunes

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Only two likely causes.

a) RF from the meter. Simple test for an electrician to do: Replace the RCD with a DP switch and move the existing RCD into a separate enclosure 1m away connected by tails. If the RCD now holds, it was proximity to the SM that was the problem.

b) SM integral isolator causing glitches in supply. As touched on by Murdoch and Johnduffell, arcing and momentary interruptions can trip a downstream RCD. This tends to occur because the sharp risetime of the interruptions cause unbalanced currents to flow to earth via capacitive interference filters in appliances on RCD-protected circuits and/or by disrupting the operation of active RCD circuitry.

If this situation persisted, I would expect to see the lights flicker or something to start overheating. The problem also existed with two SMs, so I don't think this is it.

I like Sparkychick's suggestion to get them to test a remote antenna.
 
marconi

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Ines Spires: Further to my #39 and thought (2).

https://www.securemeters.com/files/8715/3121/7040/liberty100_family.pdf

I have managed to track down the specification for Liberty 100 smart meter. On page 2 of 4 is the functionality for the Pay As You Go(PAYG) mode which I have copied below. I will make an enquiry tomorrow with the manufacturer Secure to understand this functionality better and in particular how (c) and (d) operate in practice when credit runs out.

(c) might explain why the SM cuts the supply off - which trips the rcd for the sockets- but is soon restored to allow low power demands to be supplied - such as the lighting - for a period until the meter is topped up or the emergency credit runs out. If during this period the load limit is exceeded I guess the power will be turned off again - but if some emergency credit remains the power is again restored subject to the load limit until all the emergency credit is spent. The tenants might be topping up with too little money and underestimating the cost of the electricity they are consuming and thus the rate at which the credit draws down - effectively running the smart meter on empty or close to empty much of the time - triggering the emergency credit mode. Or the top up signal is not being reliably received by the meter causing much the same thing to happen.

You or the tenants ought to ask the energy supplier whether the load limiting option has been enabled in the smart meter.

PAYG functionality

a. Credit and PAYG modes (meter maintains account and tariffs)

b. Display of current and historical consumption with cost of consumption data

c. Emergency credit with optional load limiting

d. Friendly credit (avoids disconnection during unsocial hours or weekends)

e. Debt recovery
 
marconi

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Ines Spires: I have done a bit more research and studied the picture of your meter box - I think the your wall recessed meter box is made of metal which would make it an unsuitable place to install the smart meter - a failing of the meter supplier/installer. See what OVO Energy and meter box makers TRICEL (look at Smart Meter paragraph) say here:

Electricity meter in metal cabinet - can I get smart meters? | The OVO Forum - https://forum.ovoenergy.com/smart-meter-booking-and-installations-66/electricity-meter-in-metal-cabinet-can-i-get-smart-meters-1307

Types of electricity meter & moving your meter - Tricel - https://tricel.co.uk/electricity-meter/
 
OP
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An update of where I am at the moment with E.org/SM Provider. Sorry for the length.
I thank you all so much for the advice you have been giving me.
From the advice and information supplied so far I asked E.org, who would then ask the SM provider, the following questions yesterday, replied today.

1. Me- If tenant wanted to top up SM without app - how do they do it?
E.org- with card at shop, but it would then immediately credit the SM. The SM is still a Smart Meter.

2. Me- If tenant moved to another energy supplier who can not use the Liberty 100 SM, then the E.org installed SM goes Dumb and tenant has to manually top-up, how would they do it?
E.org- shop would give a digit code which tenant would then key into SM. BUT, SM would not go Dumb - it would still be a Smart Meter and send out signals/frequencies. !!!

3. Me- I said that I totally agree with E.org /SM Provider that SM is NOT faulty.

CAUSE - WHY TRIP
But, the way ALL SMs have to operationally function and where this SM has been located is causing the the RCD to trip.
(i)-transmissions emanating from the SM is causing some form of disturbance/interference, such as electromagnetic interference (EMI), radio frequency interference (RFI) and even upstream harmonics or otherwise, which is causing the RCD to trip.

(ii)-communication parts in the Liberty 100 are at the very top of the unit - the SM has been placed immediately underneath where the RCD is in the CU - it can not get any closer.

(iii)-mobile modems vary their signal strength based on the strength of the signal they receive, so if the signal is weak, they'll boost their output accordingly to get good comms with local mast, so increase the risk of interference.

(iv)- CU and SM are in a metal cabinet - this would cause the SM to have to boost it’s signal, so increase the risk of interference.

(v)- I did not mention this point - RCD in that board will be a MEM with a functional earth wire it may act like an antennae! - I think the unfortunate guy at E.org was getting overwhelmed! Sorry TJ Anderson.

SOLUTION I REQUEST
So, to eliminate that the SM is causing the RCD to trip, I asked can E.org do the following:
(a)- the Liberty 100 can be both a SM and a dumb PAYG top terminal. It has the function to remotely or by the computer inside the meter to switch off the Smart Meter so it becomes a Dumb meter - can E.org do this?
E.org- we do not have the ability to remotely switch off the SM

(b)- the Liberty 100 has facility on the modem for an external antenna. Could E.org provide one that is sited away from the CU and disconnect the internal one?
E.org- we can not do this as we can only replace the whole SM

SOLUTION FROM E.org
The SM Provider again state that the SM can not cause the RCD to trip. BUT, the fault is because CUs only have a life span of 10 years and as this one is old, the RCD has become sensitive and so trips. To solve the problem replace the current CU with a new one.
My Response:
Me- RCD started tripping immediately after the SM was installed, and CU was fine until then - tenant was E.org Dumb Meter customer for year till switch.
E.org- Unfortunate coincidence
Me- RCD trips when tenant does top-up and and E.org do On Demand test
E.org- Unfortunate coincidence AND we do various requests during the day

WHAT CAN I DO?
1. Do test by moving RCD 1m away - Lucien Nunes #42
2. Do test RCD and MCBs - Wilko #27
3. Do test of electromagnetic radiation - Strima #29
4. Wrap CU in silver foil - how? Is it safe? - Marvo #6
5. Replace CU with new one - but would new CU still trip as next to SM?
6. Replace E.org SM with Dumb Meters - which E.org say I can do, but at my cost
7. Move to another energy supplier that would make E,org SM dumb - or would it still stay Smart as E.org say it will?
8. Get tenants to keep good credit in SM as suggested by Marconi - I believe tenants keep high positive credit, but will ask them.
9. Any other suggestions or combination of above??? Aaaargh, candles and wood burning stove???

Have just sent E.org email with links supplied by Marconi about SM in metal box. Lets see what they say.
Have requested all Logs that the SM creates. E.org asked me which ones, I said all logs (felt stupid, but have no idea bar what you all have suggested) - is there any specific ones I should ask for?
And, one other connected question - will the constant tripping cause damage to the CU/RCD or effect its callibration?
 
Strima

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There’s no need to wrap the whole DB in foil. Wrap a foil sheet around a sheet of card a couple of times. Then wrap in some plastic sheet to insulate it if you wish.

Slide this in between the SM and DB. Observe the results. This is only a temporary fix to see if you can block the local RF emissions to the RCD.

Age of the DB has nothing to do with this and they’re talking big swinging fleshy ball things...
 
marconi

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Ines Spires: Re: 9. Any other suggestions or combination of above??? Aaaargh, candles and wood burning stove???

Buy some heavy duty plastic sheeting and gaffer tape. If safe and practical, leave the meter enclosure door open. Make the innards of the enclosure watertight using the plastic sheeting and gaffer tape. Leave it this way for a week.

See Toolstation items:
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64699
All Weather Tape 50mm x 25m


25592
Polythene Sheet Heavy Duty Gauge

Polythene Sheet Heavy Duty Gauge - https://www.toolstation.com/shop/p25592?
 
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i have a customer with exactly same fuseboard with exact same issues. I insisted on the old meter going back in

hey presto fault fixed

@Wilko
Yes, BG actually observe top-ups causing trip.
Re: Remote Testing - E.org electrician change SM-tripping worse, but he could not touch CU/domestic side. So as per Wilko above, E.org electrician himself suggested that if I got an Electrician out that day, the two could work together - he work on the SM, while my man work on CU/domestic side. PH Jones electr1.ician comes and E.org electrician not contactable! PH Jones confirm 4th time, domestic side all ok.

@Murdoch
Re: On Demand test - yes, every time E.org did test while I on call with them, RCD trips
1. Yes, CU is in daft place
2. AMD3 board help - no idea as I am ignorant
3. I suggested replace SM with Dumb meters but E.org rejected idea, unless I pay cost. But, will ask Monday if they can remotely switch off SM and make it Dumb Top Up

Pictures below CU open
Only RCD - red middle switch trip
Also, tenant tells me today, that when trip happens - Plug circuit all off, But Light circuit stay on (lights work).
View attachment 45297 View attachment 45298
 
alasdairp
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This is almost certainly an RF interference issue as suggested by some of the posts above. Not only is the meter (RF in the top) VERY close to the CU, but the RF will travel up the tails into the CU.

# Ideally the smart-meter should be moved outside of the box.

# Did you actually try inserting screening between the SM and the CU? Idealy a piece of insulated Aluminium (c. 20 swg think) with a cut out to allow the tails to pass by? It should be Earthed with as short a lead as possible. That might sort it.

# I would swap the RCD for a new one - preferably a different make that will fit the CU ok. That is certainly well worth a try.

# If not, a 100nF X2 rated capacitor between across the mains L & N each side of the RCD should short out any differential RF. If it were an RCBO then you would also need Y rated capacitors to a good Earth on the incoming side. You would need someone who knows what they were doing, though!
e.g. (70p each in bag of 5; easy to fit - need sleeving)
B32922H3104M000 | EPCOS 100nF Polypropylene Capacitor PP 305 V ac, 630 V dc ±20% Tolerance B32922H Series | RS Components - https://uk.rs-online.com/web/p/polypropylene-film-capacitors/1248412/
RFI caps.jpg
# You can get in-line RF mains filters but they are bulky and very expensive
 
alasdairp
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^^

“Ideally the meter should be moved out of the box”

Me thinks the supplier will say the CU shouldn’t be in the meter box and needs to be moved ....

Actually, I agree with you there. But it is an old-ish installation and it is not uncommon to see this, especially in rented flats (etc). It would be a much bigger job to move the CU, and the CU was fine until the radio SM was fitted right up tight to it. I was mostly trying to show other ways that might well work and would be cheap, easy, effective and safe.
 
sparks55

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This is becoming more and more amongst jobs posted on my builder and similar web sites
Always seems to be EON and EDF smart meters could it be installers ???
 
marconi

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https://assets.publishing.service.g.../file/712151/2018_Q1_Smart_Meters_Report_.pdf

Page 5/18 Executive Summary third bullet:

To date, around 12.3 million smart and advanced meters have been installed in homes and businesses across Great Britain by both large and small energy suppliers – around 11.3 million (92 per cent) of these were installed in domestic properties and a further one million in smaller non-domestic sites.

With regards to the OP's reported Smart Meter/RCD problem it may well be that RF interference with this particular MEM RCCD 'is the most likely' cause. What I find surprising though is if RFI from Smart Meters is a potential problem to RCDs/RCBOs that there are not many, many more tripping problems being reported across the 12.3 million smart meters installed in the UK - I can find no reports of Smart Meter RFI-RCD tripping when I google. Nor can I find any installation instruction on minimum separation distance between Smart Meters and RCDs/RCBOs or any cautions about installing Smart Meters in close proximity to RCDs/RCBOs in safety critical supplies say in hospitals, or indeed operating mobile phones close to RCDs/RCBOs.

I remain dubious about RFI being the root cause of the RCD trips in the OP's case.
 
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Marvo

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Agree that the MEM RCD might be more sensitive than some of the other brands.

This is probably a one in a thousand or one in ten thousand issue where the brand of RCD, the lack of separation, the fact it's GSM not WiFi WAN, the poor GSM reception in the area resulting in higher transmission strengths and the CU and meter being in the same enclosure all create the perfect storm type arrangement for nuisance tripping.

Smart meters are still relatively in their infancy so the frequency of RFI problems with RCD's might not have been sufficient to warrant in depth investigations and official recommendations on distances etc. There's also the issue that with the bad press smart meters have had any RFI nuisance type reports are likely obfuscated and not openly discussed by the manufacturers and probably blamed on other things wherever possible.
 
alasdairp
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When GSM handsets first came out and were easily and affordably available, it was found that in particular seats in one make of National Express (I think it was) coaches, the automatic gearbox would change gear incorrectly if the mobile phone was used. It happened many times as was well documented at the time. Non critical electronics (and that will include RCDs) only need to be OK at 3 V/m signal strength and close to a 2W peak GSM transmitter 30-50 V/m peak is not uncommon.
 
Marvo

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I'm also still following this thread to see if any more info was obtained.
 

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