The UK's nominal mains voltage is 230V, with a legal tolerance range of +10% to -6%. This means the actual supply voltage to premises should fall between 216V and 253V. You'll need to contact your local Network Operator so they can make the adjustment at your local supply transformers.

 

The chargepoint will error above 253 volts.
It's probably worth contacting Ohme and asking if they can look at voltage levels for the past week or so to see if there's a pattern of high voltages.

If it's a one off then nothing can be done but anything persistent should be reported to your DNO where they can arrange for a monitor on your supply which will prove if it is the supply or not.

If it's a fault with the chargepoint then Ohme might be able to adjust things slightly.
If it's the supply then taps need altering at you sub station.

It's a matter of establishing where things are going wrong so Ohme need to be the starting point.

Gaz

 

Thanks chaps. I guess I call UK power networks? I'll message Ohme too. Doesn't sound like a quick fix

 

I went through this with UKPN. They were pretty good. It did take a few weeks all told.
It will definitely help if you can get some specific data from Ohme. Dates and times help.
The first step was sending an engineer to check the voltage (at that instantaneous moment) which they did same day I called them. It was within limits of course as expected since it’s usually at night the voltage is highest with low demand).
Next step was to fit a voltage recorder for a week. We had to wait a few days for one to be available. Then the week recording.
After they removed the recorder I got a call within a day or say don’t recall.
They then adjusted the transformer. I didn’t get information on that bit but the engineer said that would be the case so I was forewarned. Still it got done pretty quickly (also as he had said). I could tell from the grid voltage our solar inverter sees.

 

That's everyone. Ive called UK power networks and they're sending someone and Ohme are sending me some data. Wish me luck! Why would this happen in the first place?!

 

The local transformer will probably be putting too much power into the local grid. They seem to have a mechanical adjustment. Might also be some local generation maybe a small wind turbine or similar that has been connected adding power.
If I had to guess... maybe the transformer was set up a decade ago (or perhaps several), and since then domestic consumption has dropped a lot, so at times it will now be providing more power than the local area uses.

 

Low energy lightbulbs (I replaced 8kW of tungsten bulbs when we moved into our current place).

Heat pumps replacing storage heaters on an “all electric” estate.

Shut down of major industry in the wider area.

 

Yes, either the EVSE or the car might throw an error.

It has to, it is to protect the car.

Contact your network engineering complaints.

 

So the car is plugged in... currently the voltage is showing as 257v. No charge again then I guess

No sign of an engineer today either.

 

Sometimes you can get the voltage to drop by using some power, an electric shower or boiling a kettle or an electric heater.
Once the charge has started the drain from the car itself might be enough.

It may not work in your case as it is fairly high, it's no small margin.

As mentioned previously Ohme might be able to dial things down a bit remotely if they can see their kit is over reading, that's why getting the stats from them to shouw voltages both day and night over a week or two would be useful as the very first thing to do.
If you or a close neighbour has something they can use to read the voltage separately to the Ohme it might be a good indication of where the fault lies.

Gaz

 

FWIW our over voltage was quite variable. It would drift up and down by 5V or so. Might be possible to get it started if you just keep trying a few times. Or as mentioned switching some other power hungry stuff on may help.

 

Hang on. Hang on !! This has to be all wrong ??

EVs are going to destroy the grid and we're all going to sit in the dark no ??

I hate fake news !!

 

So the engineer did come this morning. He took a reading in the house and said it was high, but within the limits. Then he went to the substation and called me. All looks fine. But he said he can see from my smart meter that it it spiked over 259 ( didn't know a smart meter can be read remotely). He then said they will monitor the voltage from the substation for 5 days and make adjustments if needed. But he said they won't turn it down if it's just me affected. That doesn't fill me with loads of confidence....

 

If your electricity is not super expensive, you could turn on a 2kW electric heater and see if that drops the voltage in your house.

It would be a shit wasteful thing to do, but if it is the difference between getting to work or not, or driving the old diesel tank, then it's a lesser bad option, for now at least until they see this happening at the substation, which they will if your reports are accurate and I expect they are.

 

So I checked at 1am (this is getting fun!) and my car was charging. Voltage was showing as 241v. Maybe they've adjusted the transformer? Seems a big drop off.

 

I really hope it is sorted.
If the DNO decide to be awkward... You may find these old threads helpful...

(1) Supply Overvoltage ignored by DNO | Speak EV - Electric Car Forums

https://www.speakev.com/threads/help-me-understand-charger-over-voltage.187121/post-3662512