Voltage Problem

47akak

For a half hour before the power was totally cut the local area experienced a voltage issue. All of the electronic devices which can utilise American and UK standard voltages (so 110V & 230V) stayed on, anything using 230V stayed off, though some LEDs and lighting stayed on dimly lit (eg my refrigerator lights).

I would have thought there are safety features in the distribution network preventing this, and surely it is dangerous and wildly destructive of a wide range of appliances.

Before I ask ESB about it I just want to canvass a couple of opinions. Someone told me the undervoltage situation can't happen but it very definitely did happen here, for an extended period. I suspect it has happened before but I'm only certain on this occasion.

10-10-20

This appears to have been reported by another user too:

https://www.boards.ie/discussion/2058220661/electricity-went-out-for-a-moment

I don't have much to add otherwise as I don't know what under-volt protections are applied, but I'd guess that if the under-voltage is upsteam of a safety device, it might go unnoticed.

Bruthal.

Undervoltage can happen if for example, 1 phase is gone on the supply to a transformer. With only 2 phases on the primary, the secondary side will have reduced output.

Need a Username

I don’t know why I have been included in this thread

Cerco

This event is known as brownout. I experienced this many years ago and it can damage equipment due to increased current.

CoBo55

I've had it a few times ups kicked in to protect my devices, I have 4 they're definitely a worthwhile investment.

we had this once due to a failed neutral and it wrecked the electronics in a bathroom fan

Bruthal.

https://www.boards.ie/discussion/comment/118341051#Comment_118341051

That may have been overvoltage, which often happens with a failed neutral outside of a single phase premises/house in a housing estate or group of houses, although it will be acompanied by other houses having low voltage at the same time.

Well, the LED lights started flickering and the couple of non-LED ones went very dim. The fan ran really, really slowly and I couldn't switch it off in time.

Bruthal.

https://www.boards.ie/discussion/comment/118344404#Comment_118344404

Yea maybe the neutral to the house itself failed in your case, which usually does cause low voltage in a neutralised house with any loads on.

Either scenario can happen when its the star point neutral that fails, for example at a minipillar, depending on what loads are in the affected group of houses, voltage (400v) divides according to load sizes in different houses.

It’s a neutralised supply fed underground. What happened was a contractor dug up a cable further up the street.

Probably 1960s-70s era infrastructure