The standard supply for a new house seems to be circa 18KVA single-phase. I have a client who needs to make application for a supply for a new build house at 400m2 with the only certain information being that an air source heat pump is to be used for heating. The client simply does not know what the electrical loading might be. The house is only coming out of the foundations but the DNO supply may take many months as the house is in a relatively remote rural location, thus loading details are required before the DNO will consider progressing the proposal. It is a big house, but that is what it is, just a big house. I am inclined to advise a standard supply but 3-phase as with a large AS heat pump, maybe shower, cooking and perhaps an EV or two, 18KVA wouldn't be long being gobbled up. As we move towards a higher reliance on electric as a power source for some heavy current-using equipment, it might be that 18KVA is no longer a realistic standard supply for even the smaller property.
Strictly speaking Broadgauge I would not call that an overload. A shower for 15 minutes assuming that the load of everything else is at maximum, will not cause any problems.It is unlikely that electric heating will be needed in this house if the heat pump is working, and the odd kettle is nothing. Most houses with a 90A maximum demand get on very well with a 60A main fuse as you well know. Going above 100A is very expensive in switchgear and everything else. The supply charge will be much larger than 100A supply as CT metering is needed, and the head etc. is much larger, not really domestic at all. I am sure they will be fine with a 75kW supply, even with 2 car charging points. Imagine the supply transformer for a street full of these houses, every tenth one will have to have a substation in the garden! That is the real cost of these electric vehicles. Every street will have a pylon close by too, not too good for the radio buffs.
Strictly speaking Broadgauge I would not call that an overload. A shower for 15 minutes assuming that the load of everything else is at maximum, will not cause any problems.It is unlikely that electric heating will be needed in this house if the heat pump is working, and the odd kettle is nothing. Most houses with a 90A maximum demand get on very well with a 60A main fuse as you well know. Going above 100A is very expensive in switchgear and everything else. The supply charge will be much larger than 100A supply as CT metering is needed, and the head etc. is much larger, not really domestic at all. I am sure they will be fine with a 75kW supply, even with 2 car charging points. Imagine the supply transformer for a street full of these houses, every tenth one will have to have a substation in the garden! That is the real cost of these electric vehicles. Every street will have a pylon close by too, not too good for the radio buffs.
