There seems to be a standard installation developing for domestic EV charge points where it is 6mm2 no matter what. I checked one installation which will have around 9v dropped on a 7Kw charger. Ok, I acknowledge that the full load current won’t be pulled at all times but it can be assumed that there will be long periods when it will. Multiply that by an ever increasing demand across the nation and we can expect to see considerable energy wastage. Perhaps, we should be setting tighter limits than 5%.
Yes, in my view we should be considering the energy waste resulting from voltage drop. Most domestic sub circuits are either lightly loaded, or are heavily loaded only briefly. EV chargers are an exception.
The loss of 9 volts at 30 amps is of course 270 watts, or 270 KWH a year if the charger is used for 1,000 hours a year. That could cost about £40 a year.
Halving this loss by use of larger cable is therefore worthwhile. In ten years, larger cable could save £200.
Is there not a proposed regulation under which the designer of an installation is required to consider energy losses ?
Yes, in my view we should be considering the energy waste resulting from voltage drop. Most domestic sub circuits are either lightly loaded, or are heavily loaded only briefly. EV chargers are an exception.
The loss of 9 volts at 30 amps is of course 270 watts, or 270 KWH a year if the charger is used for 1,000 hours a year. That could cost about £40 a year.
Halving this loss by use of larger cable is therefore worthwhile. In ten years, larger cable could save £200.
Is there not a proposed regulation under which the designer of an installation is required to consider energy losses ?
