If national grid ignore voltage being out of spec and it damages equipment are they liable?

BarelySentientAI

prowla said:

252-259V: that's a 7V variation, or about 3%.

I'm amazed that the service can provide that stable a value over all of the infrastructure.

That's not a particularly stable voltage trace, if the measurements are only in the order of hours apart - but then voltages on some sections of the network are like that.

Chrysalis said:

Also ordered a volt meter, possibility might be a rogue , smart plug, socket or something in my home, so will check with that.

The closer (electrically) you can measure to the service head, the more you are measuring the supplied voltage (the regulated bit) and not the effect of something in your own system, although most things that could be wrong with your own system would either make the voltage jump to something stupid (>300V) or drop a little bit.

Ectophile

The difference between 253V and 259V is only 2.3%.  So you'd need a meter more accurate than that to be certain that you are over-voltage.

Good quality professional meters can be that accurate, but cheap ones won't be.

FreeBear

BarelySentientAI said:

prowla said:

252-259V: that's a 7V variation, or about 3%.

I'm amazed that the service can provide that stable a value over all of the infrastructure.

That's not a particularly stable voltage trace, if the measurements are only in the order of hours apart - but then voltages on some sections of the network are like that.

Trace from my supply over the last 24 hours. Bounces from a low of 231V to a high of 247V - A bigger variation than the OP, but still within prescribed tolerance. If the OP wanted a similar type of plot to be used as evidence, the equipment would need to be calibrated and be accompanied by a recent certificate - That isn't going to be cheap.

BarelySentientAI

FreeBear said:

BarelySentientAI said:

prowla said:

252-259V: that's a 7V variation, or about 3%.

I'm amazed that the service can provide that stable a value over all of the infrastructure.

That's not a particularly stable voltage trace, if the measurements are only in the order of hours apart - but then voltages on some sections of the network are like that.

Trace from my supply over the last 24 hours. Bounces from a low of 231V to a high of 247V - A bigger variation than the OP, but still within prescribed tolerance. If the OP wanted a similar type of plot to be used as evidence, the equipment would need to be calibrated and be accompanied by a recent certificate - That isn't going to be cheap.

The DNO should send a voltage recorder to plug in for several days at no cost to the OP, given that there has already been a report made of non-statutory voltage..

Robin9

Brings back memories to me as a young ginger beer of installing voltage recorders that had ink pens and rolls of recording paper.

Those 240V +/- 6%   Not unknown to get recordings under 200v and complaints of the tele not working well and the kettle takes ages to boil. Some were easily improved others could take over a y ?ear.

OP are you out in the sticks or in a town/city

Qyburn

I don't know if it's remotely relevant but when assessing our application for solar panels, SSEN wouldn't permit a voltage rise of more than 1.3%. In our case that would give around 243V. 

Scot_39

Older style solar invertors in past - if enough of them -  led to reports they had a nasty habit of dragging local grid voltages higher.

So each will have own limits - ultimately with the requirement to stop lifting grid above the current EU adjusted 230V -6%, +10% = 253V max in theory.  iirc was 240V +/-6% so 254V prior.

With enough solar exporters / local generation in a local area - at least in past  - DNOs  or equivalents in some countries -  actually have had to intervene to build in headroom for local generation - like making manual changes to local transformer tap settings. These days it may be more automated.

If you get a lot of solar kit alarms to that effect you could in past request a calibration certified logger to monitor from them etc as a start point.

People often buy into solar, without recognising the adverse problems low level local solar panel users - as now over 1.3m in spring 2023 in UK - approaching 5% of homes - cause for generation, grid, local distribution systems and planning.

BarelySentientAI

Scot_39 said:

These days it may be more automated.

It isn't.  

Chrysalis

BarelySentientAI said:

prowla said:

252-259V: that's a 7V variation, or about 3%.

I'm amazed that the service can provide that stable a value over all of the infrastructure.

That's not a particularly stable voltage trace, if the measurements are only in the order of hours apart - but then voltages on some sections of the network are like that.

Chrysalis said:

Also ordered a volt meter, possibility might be a rogue , smart plug, socket or something in my home, so will check with that.

The closer (electrically) you can measure to the service head, the more you are measuring the supplied voltage (the regulated bit) and not the effect of something in your own system, although most things that could be wrong with your own system would either make the voltage jump to something stupid (>300V) or drop a little bit.

To clarify the voltage is moving within seconds or minutes apart, its not hours to get from 252V to 259V.

The pattern seems to be it creeps up slowly maybe 1V every 2-3 minutes on average but they can be much quicker like seconds apart, then when it peaks all in one go it will suddenly drop several volts.  It does multiple of these cycles per hour.

Anyway I have the volt meter now, tested in the kitchen socket as easy to access, that socket has the same voltage behaviour however the meter is consistently reading about 2V lower than what my UPS reports.  The kitchen socket is very close to the fuse box, and it was directly in the socket, no extensions, no smart plug or anything like that.  I will need to move some stuff to test the socket I use for my PC as its really hard to access, I also wouldnt be able to see the meter display without moving stuff even if I managed to plug it in.

So from what I seen today UPS lowest reading is 251V and highest 261V, the lowest I seen on the voltage meter is 248V and highest 259V.

This is what I purchased.

https://www.amazon.co.uk/dp/B07GNPKHQ9

I dont know if 3% deviance in short time is considered good or not, but I know prior to the Saturday events, I seen very little deviation typically no more than 1V, and never seen it move before whilst watching it.

Chrysalis

Robin9 said:

Brings back memories to me as a young ginger beer of installing voltage recorders that had ink pens and rolls of recording paper.

Those 240V +/- 6%   Not unknown to get recordings under 200v and complaints of the tele not working well and the kettle takes ages to boil. Some were easily improved others could take over a y ?ear.

OP are you out in the sticks or in a town/city

In a city about a mile or so from city centre.