Excessive voltage on single phase supply?
Discussion
We have recently had a Sync EV charger installed at home and it was "flashing red" upon starting... the installer has called and said that our house has an excessive high voltage feed from the sub-station - reading 252/3 volts ... this compares to the UK average of 240 volts.
The consequence of this is that the charger will not operate above 250 volts due to a safety mechanism to protect the car ... therefore the answer is for me to speak to customer services at our supplier and get them to look at the sub-station to reduce the feed - this fills me with dread (maybe unfairly as i haven't called yet (will do tonight)) in terms of ever getting this resolved!
Has anyone any experience of something similar ? does the above stack up ? any thoughts from the experts on PH ?!
thanks
The consequence of this is that the charger will not operate above 250 volts due to a safety mechanism to protect the car ... therefore the answer is for me to speak to customer services at our supplier and get them to look at the sub-station to reduce the feed - this fills me with dread (maybe unfairly as i haven't called yet (will do tonight)) in terms of ever getting this resolved!
Has anyone any experience of something similar ? does the above stack up ? any thoughts from the experts on PH ?!
thanks
I recall that as part of the EU harmonisation we specified 230V +- 10% so thats up to 253V which suggests the charger is right on the limit of acceptance and probably should not be flashing and that the sub is within tollerance.
Does it do this all the time ?
Voltage on the 400kV & 132kv systems is not static and certainly you can expect some change in voltage throughout the day (as I often change 400kV transformer tap positions to cope) and I would be surprised if it remained higher then 253 all the time.
Does it do this all the time ?
Voltage on the 400kV & 132kv systems is not static and certainly you can expect some change in voltage throughout the day (as I often change 400kV transformer tap positions to cope) and I would be surprised if it remained higher then 253 all the time.
Edited by Gary C on Monday 23 August 16:00
I had something similar. The electricity people came and fitted a recording device to the cables coming into the consumer unit and measured the voltage fluctuations over a period of days.
Their eventual solution was to change the "phase" of electricity coming in to the house from the substation. As you may know, electricity is generated in three phases which represent different angles of coil in the AC generator. This change involved digging up the verge to find the cable and then physically wiring the house onto a different phase of the wires.
It was all done pretty efficiently and we haven't had any trouble since.
Description of three phase power generation and distribution here, https://en.wikipedia.org/wiki/Three-phase_electric...
Their eventual solution was to change the "phase" of electricity coming in to the house from the substation. As you may know, electricity is generated in three phases which represent different angles of coil in the AC generator. This change involved digging up the verge to find the cable and then physically wiring the house onto a different phase of the wires.
It was all done pretty efficiently and we haven't had any trouble since.
Description of three phase power generation and distribution here, https://en.wikipedia.org/wiki/Three-phase_electric...
The Electricians Guide Fifth Edition said:
For many years the supply voltage for single-phase supplies in the UK has been 240V +/- 6%, giving a possible spread of voltage from 226V to 254 V. For three-phase supplies the voltage was 415 V +/- 6%, the spread being from 390 V to 440V. Most continental voltage levels have been 220/380V.
In 1988 an agreement was reached that voltage levels across Europe should be unified at 230V single phase and 400V three-phase with effect from January 1st, 1995. In both cases the tolerance levels have become -6% to +10%, giving a single-phase voltage spread of 216 V to 253 V, with three-phase values between 376V and 440 V. It is proposed that on January 1st, 2003 the tolerance levels will be widened to +/- 10%.
So I'd suggest that your supply is within specification, but the equipment is out of spec. In 1988 an agreement was reached that voltage levels across Europe should be unified at 230V single phase and 400V three-phase with effect from January 1st, 1995. In both cases the tolerance levels have become -6% to +10%, giving a single-phase voltage spread of 216 V to 253 V, with three-phase values between 376V and 440 V. It is proposed that on January 1st, 2003 the tolerance levels will be widened to +/- 10%.
I had exactly the same issue, with the wall box switching off for protection at anything over 252 volts.. I like you thought I would get passed from pillar to post but I made one call, was promised a call from al local engineer, who did call as promised and within about an hour..
They arranged a visit to the house, which happened a few days later, they measured the house supply voltage by plugging their device in to a mains socket, monitored for about 20 minutes or so, saw that the voltage was at times exceeding 252v which was outside their threshold (Which I assume is 5% over 240v) and arranged for the local substation to be tweaked to lower the supply..
That's the only bit that takes some time as they have to notify everyone using that particular substation that power will be switched of, giving at least 30 days notice.. And in our case, there are other substations that will need to be shut down when the power down the supply from the grid..
They will be interested though as an over supply of voltage is damaging at a certain level to TVs, Microwaves etc.. and can of course lead to fire..
They arranged a visit to the house, which happened a few days later, they measured the house supply voltage by plugging their device in to a mains socket, monitored for about 20 minutes or so, saw that the voltage was at times exceeding 252v which was outside their threshold (Which I assume is 5% over 240v) and arranged for the local substation to be tweaked to lower the supply..
That's the only bit that takes some time as they have to notify everyone using that particular substation that power will be switched of, giving at least 30 days notice.. And in our case, there are other substations that will need to be shut down when the power down the supply from the grid..
They will be interested though as an over supply of voltage is damaging at a certain level to TVs, Microwaves etc.. and can of course lead to fire..
In practice it's not uncommon for mains supplies to even exceed the nominal 253 volt limit. Our office ring sits at 255.5ish, which is annoying because it trips the over-voltage warnings on some of our equipment.
The 230 +10% -6% (-10% is not allowed) thing is EU wide, people shouldn't be selling any mains equipment in the EU which can't cope with that entire range. I suspect the same rules still apply in the UK.
The 230 +10% -6% (-10% is not allowed) thing is EU wide, people shouldn't be selling any mains equipment in the EU which can't cope with that entire range. I suspect the same rules still apply in the UK.
Edited by kambites on Tuesday 24th August 19:51
kambites said:
In practice it's not uncommon for mains supplies to even exceed the nominal 253 volt limit. Our office ring sits at 255.5ish, which is annoying because it trips the over-voltage warnings on some of our equipment.
The 230 +10% -6% (-10% is not allowed) thing is EU wide, people shouldn't be selling any mains equipment in the EU which can't cope with that entire range. I suspect the same rules still apply in the UK.
Ooops, yes. The -10% was due to be brought in, but never seems to have materialised.The 230 +10% -6% (-10% is not allowed) thing is EU wide, people shouldn't be selling any mains equipment in the EU which can't cope with that entire range. I suspect the same rules still apply in the UK.
Edited by kambites on Tuesday 24th August 19:51
240V is not something I have a great deal to do with at work.
kambites said:
In practice it's not uncommon for mains supplies to even exceed the nominal 253 volt limit. Our office ring sits at 255.5ish, which is annoying because it trips the over-voltage warnings on some of our equipment.
I have my IT stuff at home on a UPS and soon after getting it had to increase the over-voltage trigger from 255 to 260 as it was going off all the time.Normally we, largeish semi-rural village, sit at 248V. Going to bed one night the UPS was beeping away and voltage was 273V - checked with multimeter and got same. Didn’t seem any other effect. Rang the DNO thinking they could turn it down a bit but they were anxious to send someone out - put them off as didn’t fancy staying up. Was surprised it was still same in morning then at 9AM it suddenly dropped.
We used to have the opposite problem - mains voltage would drop to below 180v under load (when the Aga and storage heaters were charging). They very quickly moved us to a multi-phase meter, with the economy 7 fed storage and water heaters on a different phase.
Only problem now is that we can't get a smart meter
Only problem now is that we can't get a smart meter
rscott said:
We used to have the opposite problem - mains voltage would drop to below 180v under load (when the Aga and storage heaters were charging). They very quickly moved us to a multi-phase meter, with the economy 7 fed storage and water heaters on a different phase.
Only problem now is that we can't get a smart meter
Same, I used to run a 3kw kiln in the garage and low supply voltage meant it wouldn’t hit the temperatures I needed. Ended up getting lower impedance elements for it to up the power. Only problem now is that we can't get a smart meter
Gary C said:
Where are you ?
I could probably drop system voltage in the Northwest for a few minutes to see if it works then
I liked this, the man has real power, he can manipulate megawatts with his fingertips. I could probably drop system voltage in the Northwest for a few minutes to see if it works then
The new Marvel superhero franchise is born.
'Transformers'.. Watch as he changes taps faster than the speed of light and everyone's 3kw kettle takes 5 seconds longer to boil.
Thanks all … I did have a bit of a phone run around … however persevered and eventually spoke to the right person and then sent an engineer today … measured at 253 volts which the provider said they were happy with as within the 10%.
Back to Sync EV and to be fair to them, they have agreed to update the unit and add another 10% to the existing 250 limit … so we should be sorted in the next 7 days.
At least I learnt lots during the process !
Back to Sync EV and to be fair to them, they have agreed to update the unit and add another 10% to the existing 250 limit … so we should be sorted in the next 7 days.
At least I learnt lots during the process !
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