An import or load limiting device is a piece of hardware and/or software that limits the demand (i.e. the amount of current drawn) by a premise(s). In the case of an EV charge point/Heat Pump, this can be thought of as an EV/HP curtailment scheme. This must be factored into calculations when populating the EV/HP application form. It is the responsibility of the installer to ensure that the Maximum Demand(s) stated are correct, factoring in the effects of any load limiting devices or EV/HP curtailment schemes. The load limiting device must also “fail-safe", i.e. when it is not operating or has failed, it must not result in the limitations of the connection being exceeded.
Clarification for residential properties:
When the existing Maximum Demand of a premise is above 60A, i.e. prior to any new EV charge points or Heat Pumps installed, DNOs will permit a “Connect & Notify” installation for a new EV charge point or Heat Pump under the following conditions:
- No issues with the existing connection (i.e. no safety concern, looped supply, unknown cut-out capacity, unmetered supply, insufficiently sized cut-out, etc – see Notes 1-6 on combined flowchart)
- The installation of the new device (EV charge point or Heat Pump) is installed with an EV/HP curtailment scheme such that, whenever that device is activated (i.e. drawing current), the overall MD of the property is limited to 60A or less.
Note that this clarification will be included in the updated combined flowchart and application form along with additional changes in the coming months.
Please note that this FAQ and associated clarification only refers to import, i.e. EV/HP acting as demand only, and it is not applicable to V2G/grid export limitation, which is covered by ENA Engineering Recommendation G100