Overvoltage

[Deleted User]

I work from home and in January had numerous power problems as a result of a storm. On restoring power some computer equipment failed to work. I have since been watching my mains voltage using tested professional equipment and at times my mains voltage has been 260volts, yes 2 6 0. I have spoken to the utility company who attended and agreed that I was right. That was a month ago and I am still awaiting them to install a data logger. Sitting her Sunday morning at 9am it's 255 volts.

I asked about my damaged equipment and basically the answer was no its not our problem and you prove it. How when there are well laid out standards 230v plus 10% minus 6% which they are clearly outside of and given that I can prove this equipment was damaged during the period of numerous power disturbances there appears nothing I can do?

Any thoughts would be appreciated.

Cardew

There are scores of posts on MSE about apparent damage caused to appliances by voltage surges. There seems to be mixed success on claims.

I suggest you search this forum using terms like 'voltage surge' or 'power surge'.

[Deleted User]

Thanks. I'm really asking about the legality of the situation in that whereas most people talk about surges, with little or any actual evidence, I am talking about virtually continuous periods of voltage over the 230v +10% standard.

FullForce

Deleted_User wrote: »

I work from home and in January had numerous power problems as a result of a storm. On restoring power some computer equipment failed to work. I have since been watching my mains voltage using tested professional equipment and at times my mains voltage has been 260volts, yes 2 6 0. I have spoken to the utility company who attended and agreed that I was right. That was a month ago and I am still awaiting them to install a data logger. Sitting her Sunday morning at 9am it's 255 volts.

I asked about my damaged equipment and basically the answer was no its not our problem and you prove it. How when there are well laid out standards 230v plus 10% minus 6% which they are clearly outside of and given that I can prove this equipment was damaged during the period of numerous power disturbances there appears nothing I can do?

Any thoughts would be appreciated.

Deleted_User wrote: »

Thanks. I'm really asking about the legality of the situation in that whereas most people talk about surges, with little or any actual evidence, I am talking about virtually continuous periods of voltage over the 230v +10% standard.

Put simply, the legal position with regards to this matter, as it applies to any contested dispute, is that the obligation lies with the claimant (i.e. you) to prove their claim, not for the defendant to disprove it.

Whilst the circumstantial evidence may assist you in proving your claim, it will not be enough on it's own in this instance to prove your claim.

[Deleted User]

Thanks. Well the fact that their engineer agreed there was overvoltage (albeit verbally) and second that a data logger is going to be installed should help that. Third that I too have voltage data logger (not your £20 plug in device but a £1200 bit of kit) should also help.
However again I would ask about the out of spec issue. There are laid down guidelines -6% +10% for national supplies and given the present issues with regarding electrical fires with domestic appliances then surely continuous periods of over voltage should not be taken so lightly?

keith1950

An overvoltage usually referred to a massive rise in voltage caused by an open circuit earth or other fault where the 3-phase voltage of 415 is dumped into a residential house/street.
Although the voltage may normally rise and fall by ,as you say , 10% occasionally it drifts further and a voltage of 260 will not cause any harm.
As has been stated it is up to you to prove any damage has been caused.
I used to work for a regional electricity company and I covered overvoltage call outs.
In all instances all appliances in the house were affected and also everybody on the same phase in the street would be affected.
Your only hope of proving anything is if you can find other neighbours who have had equipment damaged.
Even the mains supply being interrupted can cause a minor spike that might finish off some equipment but I think you focus on a steady voltage of 260 is totally misguided.

[Deleted User]

Thanks for the reply. I am always amused by the attitude that just because only one person reports a problem then there can't be a problem. If you read the story about Sully the pilot of the aircraft that came down in the Hudson the board of inquiry had exactly the same attitude about twin engine failure saying that it had never happened before to which Sully replied someone has to be first...
Anyway, the equipment, a UPS (uninterruptible power supply) has been replaced.
The point is if more than 253volts is acceptable when regulations clearly state 230v + 10% at what point does it become unacceptable, 265v, 270v, if so why do the regs say 253 maximum? The regulations are there for a reason are they not? It's rather like someone claiming to the police that being caught for speeding doesn't count because there was no danger. The speed limit is there for a reason, ditto the concentration of chlorine in drinking water etc etc, so why is a voltage exceeding the 253 figure acceptable?
By the way the engineer said that it may be that the tapping on the local transformer that needs to be changed. I'm not an electrical engineer but I am a building services engineer so have some understanding. I assume that tappings are provided so that sufficient voltage is available at the far end of a supply system when under load. I assume this is why I get 260v overnight and 252v right now, midday Sunday. I am very close to the transformer.

[Deleted User]

260V is out of tolerance, but not by much, if I were designing a bit of kit to work up to 253V I would have to bend over backwards to make it fail at 260V. The difference between 253 and 260 is only 2.8%, what's the logger accuracy?

You refer to "numerous power problems as a result of a storm" but then mention that no more, and focus on the voltage tolerance after the event. If anything damaged your appliances, it's a lot more likely to be a large transient than a small continuous overvoltage.

[Deleted User]

Jack. Thanks for the reply.
Yes fully understand all this. The night of the storm the power was going on and off quite a lot. Trying to sleep through it so cannot be precise. Had the UPS not been destroyed the internal logger would have told me. Every time it went off after a few seconds it would come on again for a sec or so and go off again, usually repeating this once more. My UPS went into alarm the first time and closed down my server automatically. Anyway as I say that has all been resolved by me obtaining another unit.
I agree completely about the tiny percentage margin of 260 over 253 but for the sake of repeating myself if 253v is the stated maximum in the regulations then why am I being told that 260v is ok and nothing to worry about. Shall I sit back and not worry when it gets to 270v?
I repeat question the 253v figure is there for a reason yes or no?
If yes then why is it acceptable to exceed it? If it's not there for a reason then what voltage is the limit?

AndyPK

It's worth trying to get the 260V issue sorted, as I may fix the problems you experience during power cuts

[Deleted User]

The tolerance is there because you have to draw the line somewhere, but having drawn the line, you still end up with a subjective decision about what to do with it. You can turn your argument the other way round: when do you decide to dig up the whole neighbourhood and renew the installation, when the voltage reaches 253.1V? 253.01V 253.00000001V?

The bottom line is that 260V is a minimal breach of the spec., so their motivation to dig up your street is minimal too.