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[guest]

I have an APC 1500VA UPS in the garage from the days when you actually needed that much for home servers - it runs at about 13% load now on a 2 year old  battery

Anyway I (once again - long story) sorted out the UPS alerts so it emails me when there's extended under/overvoltage or mains failure.

Lots of extended overvoltage alerts.

By overvoltage I mean well over 253V, which is the max spec (230V +10%/-6%).

258V is commonplace & we've had 260V in the last day or two. Initially I looked at the overvoltage graph & thought "its at low-demand times", but its not.

The correlation is nearly 100% when the wind speed is over 10mph regardless of time of day - when the wind speed averages 15mph our mains voltage is running at 257.5V and increases to around 260V. The rest of the time then its high (248-250V) but its in spec.

I intend complaining to Western Power Distribution (they deal with mains stuff outside the house here) but I don't really see what they can do about it other than pay daily compensation. Haven't looked into this much but if your mains voltage is out of spec you are entitled to daily compensation rates AFAIK. For anyone wondering "does it make any difference" then yes it does on all your lighting - LED bulbs will blow very early IME.

Was just really surprised that the grid is under that much stress from "renewables".

Edit - we don't have any wind/solar stuff so this is the mains grid voltage varying.

[Weaver]

Is there a suitable device that could sit at the input to the server and clamp the voltage, preferably without catching fire?

I wonder what the graph of that over voltage looks like? Ripple? Peaks? Or steady and relatively smooth average over-spec.

[JGO]

What about a Constant Voltage Transformer ?

Not heard of one for years but AIUI variable input voltage and constant output - NB used to have a reputation for distorting the waveform so may need filtering. Other alternative would be an automatic  motorised variac device - probably not economic .

[guest]

Is there a suitable device that could sit at the input to the server and clamp the voltage, preferably without catching fire?

I wonder what the graph of that over voltage looks like? Ripple? Peaks? Or steady and relatively smooth average over-spec.

The UPS will produce its own 240V sine wave when the voltage is over/undervoltage so that's not really an issue for the server - its the rest of the house which bothers me (specifically some LED bulbs which keep popping, now I know why).

The graph of the voltage is mainly spikey when viewed on a 24 hour scale - its only when you reduce the timescale that the correlation with wind speed becomes apparent. Eg we had some overnight wind which peaked at about 15mph about 3am & died away around 5am; I have an email from the UPS about extended overvoltage at 03:43 and the graph shows the voltage back in spec at 5am.

I took a multimeter next door yesterday & checked their supply - its out of spec too (different phase) so presumably anyone using 415V three-phase around here is actually running at 465V....

[Dray]

Interesting view of the problem here https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/293405/05-1410-electrical-supply-tolerances-and-appliance-safety.pdf

[Ronski]

I have the same UPS at home, I'll have to figure how to log/look at the graphs and see what our electric is doing. I also have a ups here at work, but it is more basic, so not sure if it will log voltages although does have overy voltage protection.

[guest]

I have the same UPS at home, I'll have to figure how to log/look at the graphs and see what our electric is doing.

Depends on the version of PowerChute which you use and whether you have a Java runtime environment (JRE) installed.

I have v9.1.1 installed so just hit the "Voltage Analysis" icon and select the time period - this only deals with the last day however. If you require a longer timescale for logging then you need a JRE installed to view the logs within PowerChute - right-click the relevant UPS in PowerChute, select Properties then the Log Files option.

[vic0239]

I had the same problem here a few years ago, my UPS would go onto battery for no apparent reason from time to time. I didn't have monitoring software at that time, but measurement of the voltage with a meter indicated it was over specification. I contacted my power company and to my amazement they responded and sent an engineer to fix a "device" to my incoming power cables. After a week of monitoring they accepted there was a problem and tweaked something at the substation in the village to reduce the voltage and problem solved.

[guest]

I had the same problem here a few years ago, my UPS would go onto battery for no apparent reason from time to time. I didn't have monitoring software at that time, but measurement of the voltage with a meter indicated it was over specification. I contacted my power company and to my amazement they responded and sent an engineer to fix a "device" to my incoming power cables. After a week of monitoring they accepted there was a problem and tweaked something at the substation in the village to reduce the voltage and problem solved.

I'm trying to find the relevant document again but I think the compo for out-of-spec mains voltage is in the order of £2 or £3/day for a consumer so it'll mean free electricity if they don't fix it

You'll find that the distribution companies are very good in terms of responding to consumers - unlike the retail companies which are bloody awful....

[tickmike]

I intend complaining to Western Power Distribution (they deal with mains stuff outside the house here) but I don't really see what they can do about it

Tell them to look at the 'Tap changer' in the local sub station it's not doing it's job !.

[Ronski]

Depends on the version of PowerChute which you use and whether you have a Java runtime environment (JRE) installed.

I have v9.1.1 installed so just hit the "Voltage Analysis" icon and select the time period - this only deals with the last day however. If you require a longer timescale for logging then you need a JRE installed to view the logs within PowerChute - right-click the relevant UPS in PowerChute, select Properties then the Log Files option.

Yes I have the same versions, looking through the log via the web interface our voltage tends to rise to 250v in the early hours of the morning.  Any idea where the log is stored, can't seem to find the voltage log?

[Starman]

I work for a DNO company (Not WPD). As Dray already provided the link for the UK supply tolerances which are generally quoted as 230V +10/-6% [253V/216V]. High and low voltage can be caused by grid wide issues or even a local issue with the LV main, fuse way at the substation, tap changer setting on the local transformer or even the neutral conductor on the service cable itself. Common with a 1970/80's type plastic cable which had aluminium neutral conductors.

All I suggest if you contact your local DNO report high voltage they should send someone round to inspect your service cutout, the local substation and if required install a voltage recorder to monitor directly at the cutout.

Out of interest - Do you have a overhead or underground service? A picture of your service cutout (near the electricity meter) might be useful.

[Ronski]

I've been getting extended over voltage emails from my UPS, every night for the last week, so I've done a little bit of digging around tonight.

There was no option to export the log, but I found the log file C:\Program Files (x86)\APC\PowerChute Business Edition\agent\DataLog and opened it with NotePad++ and found it was a text file with the values seperated by a TAB chr, so I replaced the TAB's with a comma and saved it as a CSV which allowed me to open it with excel.

From that I came up with the attached graph, and you can clearly see the top line where it goes over voltage (blue) and the UPS switches in and the voltage drops as per the brown line.

I'll give the local DNO (UK Power Networks) a ring tomorrow and see what they have to say.

[sevenlayermuddle]

Out here, middle of back of beyond, the problem is under voltages.

It happens once a year, regular as clockwork, Christmas Day.   There's no automatic alert, just a realisation that the roast potatoes aren't really browning, and turning up the oven doesn't help.   A voltage check shows we have dropped to circa 210V.   That's only just outside the tolerance of EU-compatible 230V, but even further from the nominal 240V for which our elderly oven was designed.   

I assume it is because we are in a rural area and at the very end of a line.  Coupled with a usage-peak like Christmas morning, it may be quite hard to bring my voltage up to spec without sending those across the village out of spec with over voltage?   Not much point in asking for a voltage monitor though, unless they let me book it just for that one, special day.

[Weaver]

So they need thicker conductors / better conductivity?