There is guidance in the IET Code of Practice for EV Charging Equipment Installation on supply adequacy (Maximum Demand) assessment. This information is critical to understanding if the EV charge point or Heat Pump can be supported by the network.
There are different approaches to determining a site’s MD, including:
- Use existing information – this is the best approach when there is available data on the specific loads in the house. However, this may not always be the case.
- Determine loads installed – this approach takes diversity into consideration where appropriate. For this purpose there are different guidelines to assist installers, including:
- Electrical installation design guide – calculations for electricians and designers
- On-site guide BS 7671:2018 – IET wiring regulations, 18th Edition
Please contact the IET if you have further questions on the guidance.
Some installers may chose to post their customers an internet connected monitoring device which connects to the customer’s internet router and clamps a split Current Transformer (CT) around the supply meter tail. Data is then remotely collected over two weeks at ten minute intervals, before being analysed to arrive at an accurate MD without the need for a site visit.