Where to start diagnosing high voltage spikes?

[von555]

Yeah well it looks like they might all have gone away. Just the diggers left and they say their job is filling in the hole. So may have missed my chance. I was going to say that the voltage looks pretty stable (between 235 and 250) but currently running at 260. I guess if I don't get to ask somebody I will just have to wait and see...

It's actually been much more stable over the last hour. You can see the break in the graph, where they shut off the power (240 marked in red):

Untitled

• von555
• 6 Dec 2012
• 1

 

[JBR]

Intriguing. I hope you find out the cause and let us know.

 

[von555]

I doubt I'm going to find out why it happened. Here's the latest voltages. I assume that it's fixed though. So must have been a problem outside...

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• von555
• 8 Dec 2012
• 1

 

[JohnW2]

I doubt I'm going to find out why it happened. Here's the latest voltages. I assume that it's fixed though. So must have been a problem outside...[/net]

I'm not used to looking at these things, but have to say that I'm rather surprised that you're seeing that amount of variation.

Kind Regards, John

 

[EFLImpudence]

This is so easy to check I can't believe you have not rushed out and bought a voltage tester.

 

[Monkeh]

This is so easy to check I can't believe you have not rushed out and bought a voltage tester.

Because one of the £3.99 jobs from his local DIY store is safe and accurate.

 

[EFLImpudence]

This is so easy to check I can't believe you have not rushed out and bought a voltage tester.

Because one of the £3.99 jobs from his local DIY store is safe and accurate.

Oh well, carry on with the speculation then.

 

[von555]

Actually I did go and get a plug in meter. Seems to be giving similar readings. Maybe not quite as high. But obviously I can't log the meter so it's harder to be sure. I also have a multi-meter.

 

[westie101]

Over what timescale as the last graph? It's still in excess of 253V which would concern me

 

[von555]

Each reading is 2 seconds. Each curvy bit is about 1 day I guess.

 

[westie101]

I would suggest that though they have corrected what appears to have been a neutral fault, it is still strictly outside limits.

 

[von555]

I would suggest that though they have corrected what appears to have been a neutral fault, it is still strictly outside limits.

Er okay. Then what is the solution? My UPS hasn't been acting up since they fixed it. Is it really something that needs investigating further? Are we talking get an electrician in to check wiring?

 

[westie101]

Nope it's still up to SP to continue to investigate and resolve, it should not be exceeding 253V for more than 5% of the time, if at all.
A simple 2.5% tap down of the supply transformer may be needed

 

[von555]

The power guy said he'd checked the substation and checked the house input. Do we get onto them to install a voltage recorder then? To be sure there's a problem?

 

[westie101]

I would say yes