Andrew Green
New User
- Location
- Bedford, UK
- Occupation
- Consultant
I am moving my meter and need to upgrade to 3-phase to account for future loadings.
I had planned to add a solar array with a total of 16.4kWp with a 12.5kW inverter, a 3-phase 20kW air source heat pump and a 3-phase 22kW rapid car charger. The items are spread across a house, barns and garage.
My electrician has advised that I would be looking at 60 amps for both the outbuildings and the house. He has applied diversity to the domestic circuits. The sub-mains to house and outbuildings are both 63 amps per phase (single phase). So, in kW this is 11kW each, and in kVA it is just under 14kVA each.
Applying diversity to the motor ratings for the inverter, EV, etc. the electrician advises that we can bring the total amps down to 70 amps approx. per phase. This is approx. 16kW per phase, and in kVA amounts to 20kVA per phase. Power factor correction used for these calculations is 0.8.
Therefore, overall, we are looking at 48kVA per phase, which is approx. 70 amps per phase. As with all maximum demand calcs which include diversity adjustments this is an approximation, but this falls below the 69kVA (100 amps per phase) and also allows some expansion for the future.
However, this would require an upgrade to the supply cable by UK Power Networks and I want to try to avoid this. Please can someone advise me re the following question....
If I swap out the 3-phase 22kW car charger for a single phase 7kW and swap out the 3-phase 20kW heat pump for 2x single phase 10kW heat pumps with staged start-up what can I reasonably reduce the load requirement to?
Thanks in advance.
I had planned to add a solar array with a total of 16.4kWp with a 12.5kW inverter, a 3-phase 20kW air source heat pump and a 3-phase 22kW rapid car charger. The items are spread across a house, barns and garage.
My electrician has advised that I would be looking at 60 amps for both the outbuildings and the house. He has applied diversity to the domestic circuits. The sub-mains to house and outbuildings are both 63 amps per phase (single phase). So, in kW this is 11kW each, and in kVA it is just under 14kVA each.
Applying diversity to the motor ratings for the inverter, EV, etc. the electrician advises that we can bring the total amps down to 70 amps approx. per phase. This is approx. 16kW per phase, and in kVA amounts to 20kVA per phase. Power factor correction used for these calculations is 0.8.
Therefore, overall, we are looking at 48kVA per phase, which is approx. 70 amps per phase. As with all maximum demand calcs which include diversity adjustments this is an approximation, but this falls below the 69kVA (100 amps per phase) and also allows some expansion for the future.
However, this would require an upgrade to the supply cable by UK Power Networks and I want to try to avoid this. Please can someone advise me re the following question....
If I swap out the 3-phase 22kW car charger for a single phase 7kW and swap out the 3-phase 20kW heat pump for 2x single phase 10kW heat pumps with staged start-up what can I reasonably reduce the load requirement to?
Thanks in advance.