Many utilities choose to undertake load control for various different reasons. In a load control event, the EVSE/charger signals the vehicle that it is not allowed to pull power. The vehicle will stop charging. Once the control event is complete the EVSE/charger signals the vehicle, communicating that X amount of current is available to pull. It is down to the vehicle to act upon that signal.
Occasionally, a vehicle may choose not to resume charging. If there are no red error lights on the front of the unit, and the power light is still on the unit, this may be a software glitch on the vehicle and has been identified on the Tesla Model 3's. The remedy is to do a hard reset on the vehicle. This can be achieved by following the instructions below.
Tesla Model 3 Hard Reboot
1. Hold down both steering wheel buttons and press on the brake until the screen goes black. Continue holding until the Tesla logo appears
2. Then let go
3. The Power Off/On options is now in the software menu under Vehicle Controls -> Safety and Security > Power Off (wait 2-3 minutes before pressing the Brake)