Where to start diagnosing high voltage spikes?

[Monkeh]

He's already had it replaced once..

True, but the first one may have (coincidentally) had entirely different problems. The voltages being reported by the UPS are so high so it only needs someone with a meter to determine if thsoe figures are in the correct ballpark or not - I was just wondering whether the DNO would/will charge for attending if it transpires that the UPS's voltage measurement is the problem.

Kind Regards, John

Stretching coincidence a bit far, aren't we?

 

[JohnW2]

Stretching coincidence a bit far, aren't we?

Hard to tell - the OP hasn't told us what problems the first one exhibited. If it, too, experienced 'over-voltage shut-offs', then I would agree that we would be stretching coincidences beyond credibility, but were it some other type of problem ...

Kind Regards, John

 

[JohnW2]

Duplicate deleted

 

[westie101]

I was just wondering whether the DNO would/will charge for attending if it transpires that the UPS's voltage measurement is the problem.

We wouldn't!

 

[JohnW2]

I was just wondering whether the DNO would/will charge for attending if it transpires that the UPS's voltage measurement is the problem.

We wouldn't!

That's good to hear - but have you any idea whether all DNOs would say the same?

Kind Regards, John

 

[ban-all-sheds]

If they are affecting other customers, requiring them to switch off the panels or face disconnection!

Oh go on, go on, go on, you know you want to.

 

[von555]

The first UPS I had was acting exactly the same as the new one. These are APC models and come with a certificate of testing (a receipt that looks like an engineer has signed off on it). APC support haven't been much help, but it doesn't seem to be a calibration problem.

Here is a graph of overnight.

Untitled

• von555
• 6 Dec 2012
• 1

DNO engineer reckons its probably a problem their side. Couldn't find anything particularly wrong here, so he's off to the substation. Then talk of installing a voltage recorder. He seemed pretty certain it's not a problem with the UPS.

Getting there then. And seemingly not a DIY job.

Update: Now they're going to dig up the front drive...right now...

 

[ban-all-sheds]

True, but the first one may have (coincidentally) had entirely different problems.

Or may have had exactly the same problem if there's a bad batch or if it has a design flaw.

The voltages being reported by the UPS are so high so it only needs someone with a meter to determine if thsoe figures are in the correct ballpark or not

Hmmm...

Here's the chart with 253 & 260v marked.

The chances of anybody putting a meter on it and saying anything other than "No, it's fine", or "Well, it's a bit high..." are low.

 

[von555]

Like I said, the DNO seem pretty sure it's a problem outside the house. Hence them digging it up today. The engineer reckons it'll be sorted by tonight.

The replacement UPS was a different model, same make. I think it's unlikely that they're both suffering from the same problem.

The engineer seemed certain there was a problem as the hall lights he was stood under were flickering.

 

[JBR]

I'm intrigued to know what, under your drive, could be responsible for voltage increases. Please let us know what the engineer finds.

I don't want to sound paranoid, but our lights flicker/dim a little from time to time, and lamps blow with amazing regularity! Of course, that could be the freezer kicking in and cheapo lamps!

 

[von555]

Well it certainly wasn't a flickering light that got me concerned.

The new engineer has a strong Scottish accent and I'm damned if I understand what he's saying. Something about a new joint that will sort out the problem? We'll see...

 

[JohnW2]

I'm intrigued to know what, under your drive, could be responsible for voltage increases.

So am I - I wait with bated breath!

Kind Regards, John

 

[westie101]

Hmm I could hazard a guess, but without knowing all the info I'm reluctant to post it.

I wonder what the voltage readings at the substation were?

 

[JohnW2]

The voltages being reported by the UPS are so high so it only needs someone with a meter to determine if thsoe figures are in the correct ballpark or not

Hmmm... Here's the chart with 253 & 260v marked.

The chances of anybody putting a meter on it and saying anything other than "No, it's fine", or "Well, it's a bit high..." are low.

Eh? I think you must understand me. I was suggesting that, as your lines on the graph show, if those figures are correct, then the chances of someone putting a meter on it and find a voltage <253V (and therefore declare that "the supply looks fine") are pretty low.

Kind Regards, John

 

[westie101]

f those figures are correct, then the chances of someone putting a meter on it and find a voltage <253V (and therefore declare that "the supply looks fine") are pretty low.

Which suggests to me that the electrician may never have actually checked that! (nor, I suspect, did he check the ELI which may be a bit on the high side)