Intermittent fluctuating voltage

[ALB]

We have a problem in my daughter’s new build house (2 years old).

She noticed the problem started 2 weeks ago when her lights would flicker at random. The lights can be ceiling lights and table lamps so it’s affecting the lighting circuit and sockets both downstairs and upstairs. I have hopefully attached video of the flickering to both ceiling and table lamps. There is no pattern to when this happened and normally lasts for less than a minute, it also makes no difference if the system is under load because she can be in bed and her table light will occasionally flicker.

SSE have been called out to check the supply to the house and all connections are good and voltage is constant. We have also had an electrician to check the CU and all connections are good with consistent voltage there as well. I should mention it makes no difference whether the system is under load or not, it happens with her cooker on and off and she’s also noticed once with her hairdryer slowing down then speed up again. Neighbours have not noticed anything with their supply.

I was there yesterday to monitor the voltage when the flickering started, after waiting for 1 ½ hours we experienced the first flicker and I measured the voltage on a meter. The voltage dropped from a steady 232v to fluctuate around 210-215v this lasted less than a minute and then settled back – see video. I stayed there for another hour and nothing, how often these fluctuations to voltage happens we don’t know, she only notices when her lights are on.

Does anyone have any idea where to go from here?
Thanks

 

[Pete999]

Loose connection somewhere I would think

 

[bill01803]

If checking for a loose connection has no results it could be arcing in the supply cable caused by damage to it

 

[Pete999]

Loose connection somewhere I would think

I think what is needed is some form of supply monitoring experiment done by the DNO, over a period of time.
Or you could pay someone to install it for you, not sure of any cost implications, sorry but that's my take, procrastinating about what it could be is fairly useless, without evidence.

 

[marconi]

In a street, the houses are usually supplied from one of three 'phases' and the same 'neutral'. So, some of the houses/flats in the road your daughter lives in will be supplied by the same phase. I suggest you knock on the doors along the street and ask if they are experiencing the same problem. This helps to determine if the flicker is caused by a supply problem rather than something particular to your daughter's home wiring.

 

[telectrix]

possible corroded or otherwise damaged joint in supply cable under street. your problem may be due to a neighbour pulling the heavier load, thus putting a strain on the damaged joint, the problem affecting your property rather than the neighbour's.

 

[Midwest]

I'd call SSE again. Here's another DNO's take on it;
Voltage Changes - SP Energy Networks - https://www.spenergynetworks.co.uk/pages/voltage_changes.aspx

 

[The Ghost]

Have you sent that video and the fact an electrician confirms internal supply is ok to your DNO? I am in the south west and have a power quality analysis device if you were close enough I could plug it in, or as @Pete999 said get the DNO to do it.

 

[ALB]

I've asked my daughter to get in touch with southern electric this morning and to pass on the video to them plus inform them the CU has been checked by an electrician. I've asked her to request a recording device be fitted to monitor the incoming voltage, hopefully they'll agree. Thanks for the offer Vortigern but we live in South Wales. Thanks for the replies.

 

[MJPD29]

If it is not the tails into the CU/meter/cutout then it sounds like it must be a supply cable issue if it is effecting all circuits

 

[DPG]

Agree with asking a few neighbours as recommended above. Not just next door. Keep us posted.