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%.
VD = 7.3 mV/A/m so that gives a cable length of (9/0.0073)/32 = 38.5 m.
If you want to reduce the losses by at least 50%, you will need 16 mm² cable. For SWA, price difference at TLC is about £5/m = £200 for 40 m. VD is reduced from 9 to 3.5 V so losses are reduced by 165 W, which costs about 3 p per hour. So the payback point is at 6700 hours.
VD = 7.3 mV/A/m so that gives a cable length of (9/0.0073)/32 = 38.5 m.
If you want to reduce the losses by at least 50%, you will need 16 mm² cable. For SWA, price difference at TLC is about £5/m = £200 for 40 m. VD is reduced from 9 to 3.5 V so losses are reduced by 165 W, which costs about 3 p per hour. So the payback point is at 6700 hours.
