Thoughts on a supply

[Spoon242]

I have been asked to look at a consumer unit which is sometimes reading 310V on a meter as read by a plumber who was working on the boiler.

I am going to measure with something better than a multimeter to see what readings are there, but I believe sometimes it does read correctly at 230V.

Thoughts please,

 

[Deleted member 26818]

The nominal voltage is 230V, but it is allowed by I believe ESQCR for the voltage to be +10% and - 6%.
Anything outside of those figures, should really be reported to the DNO, but whether they will do anything, other than suggest you install surge protection is another matter.

 

[malcolmsanford]

I'd be amazed if it was as high a 310volts to be honest, as we would be talking about serious appliance damage at that sort of voltage.

Check with your MFT the flukes I know have a voltage range, and most Zs test also include a voltage reading, this way at least you will have a calibrated unit to test with.

Bottom line though is that you will have to really fit a voltage logger to the system for perhaps a week and monitor it, to have a true record of what is happening.

 

[Spoon242]

Thanks Spin,

Even at +10% 310V is very high. I wondered if the transformer was having some issues. I have asked the lady to ask her neighbours if they have been experiencing any issues before I go around this evening to try and build up some 'better picture' of experience.
I believe its only happening in the evenings once everyone come home, but I can not confirm this till later after visiting her.

 

[IQ Electrical]

I have been asked to look at a consumer unit which is sometimes reading 310V on a meter as read by a plumber who was working on the boiler.

I am going to measure with something better than a multimeter to see what readings are there, but I believe sometimes it does read correctly at 230V.

Thoughts please,

I'll be amazed if you're getting that level of overvoltage, it's not unusual to see the 253V level breached but so rare to see anything above 260V.

I wonder if he was measuring to a 'floating earth'?

 

[Spoon242]

I'd be amazed if it was as high a 310volts to be honest, as we would be talking about serious appliance damage at that sort of voltage.

Check with your MFT the flukes I know have a voltage range, and most Zs test also include a voltage reading, this way at least you will have a calibrated unit to test with.

Bottom line though is that you will have to really fit a voltage logger to the system for perhaps a week and monitor it, to have a true record of what is happening.

Yeah,

I will through my fluke on it and see what I see. A voltage logger would be nice too. Not given that a serious option thought.

 

[Spoon242]

She has been experiencing random lamps blowing around the house, possible related shower issue and the reason for the plumber, thinking her boiler was broken.

 

[IQ Electrical]

You will need the logger if you are to challenge the DNO and request a 'tap down' on the supply transformer.

Here's a brief factsheet with the parameters as set out in BS EN 50160

 

[Spoon242]

You will need the logger if you are to challenge the DNO and request a 'tap down' on the supply transformer.

Here's a brief factsheet with the parameters as set out in BS EN 50160

Cant open it IQ, could you backward save it please. Im at work and only have word 2003

 

[IQ Electrical]

She has been experiencing random lamps blowing around the house, possible related shower issue and the reason for the plumber, thinking her boiler was broken.

Anyone else thinking poor neutral connection?

 

[silver surfer]

Anyone else thinking poor neutral connection?

If its not a cheap B & Q tester that the plumbers using, i would say Neutral connection as well.

 

[malcolmsanford]

She has been experiencing random lamps blowing around the house, possible related shower issue and the reason for the plumber, thinking her boiler was broken.

Anyone else thinking poor neutral connection?

Enthusiastic Pikey's??

 

[Knobhead]

Anyone else thinking poor neutral connection?

A floating neutral? Every possibility with those kinds of voltages. Especially if the voltage shifts at specific times of day.

Surprising things haven’t started to go bang yet!

Spoon is this a rural or residential area?

 

[paturback]

Anyone else thinking poor neutral connection?

Struggling to see an alternative with that reading

 

[Engineer54]

The neutral connection is about the best theory so far, based on the information given to date. Another factor pointing towards the neutral is the time this happens, evening time. That's when all the cooking appliances are on, a fair few showers too, and so one would expect the voltage to drop rather than increase....