Enphase › system controller / smart switch
Backup shuts down when large loads start together
manufacturer says
Symptoms
- During a grid outage the whole system shuts down, or the backup circuit breakers trip, when large loads come on together (heating or air conditioning with heat strips, water heater, dryer, oven, EV charger, or an AC compressor plus microwave plus refrigerator started at once) although the batteries still hold plenty of energy
- Two IQ Battery 10Ts run a one-storey three-bedroom home for roughly an hour of normal use
- The IQ Load Controller fitted to shed loads cannot handle those circuits. On a PV-only Sunlight Backup system (Enphase's own laboratory demonstration) the lights dim and a motor load slows as loads are added or a cloud passes, and when the load is too large for the sunlight available, typically an old high-inrush appliance such as a vacuum cleaner started in mid-afternoon light, the voltage collapses and the whole microgrid shuts off, coming back as soon as the offending load is removed
The cause and the fix
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