We’re going off grid and I’m looking for a way to signal to one of three hpwc gen2’s (master) to signal the cars to stop charging. Brute force would be to use a contactor to kill 240v. We have 12kw of inverters and I need the cars to stop charging if the hvac compressor needs to start and/or I f the house battery is low. The compressor is easy .... I just put a time delay on the compressor start of say 30 seconds and immediately signal for hpwc to stop. I’d hope the cars stop in 29 seconds. Low home battery can be signaled by a small relay inside the inverter.
ireally hate the idea of dropping a contactor on a 40 amp load. What about interrupting the ground to make hpwc fault? Or I could interrupt the pilot wire in the charge cable but I’d have to do that on all three hpwc.
anyone got any other ideas? I’m trying to keep this really simple. At one time I thought of running a raspi pi and Mqtt but that’s a lot of “moving parts”.
ireally hate the idea of dropping a contactor on a 40 amp load. What about interrupting the ground to make hpwc fault? Or I could interrupt the pilot wire in the charge cable but I’d have to do that on all three hpwc.
anyone got any other ideas? I’m trying to keep this really simple. At one time I thought of running a raspi pi and Mqtt but that’s a lot of “moving parts”.