Anyone working to Off Grid
Its time to make a couple upgrades to the 20KW inverter. 2 items need some improvements:
The small pump motor thats being powered by PWM supervised by a thermistor in the liquid cooled heat sink needs a different method. Lower temperatures cause a PWM signal that makes the little pump motor squeal in a high pitch. Not cool!! at night to hear that squealing noise coming from the garage. I going to change that out for a simple snap switch to simply turn it on and off around 30 Deg C.
also another snap switch for over temp incase for some reason the pump becomes inoperative. 85 Deg.C
The choke coil although it didn't burn off its enamelled wire insulation during high current demands it did get hot. So its now re-wound with heavier gauge copper.
The inverter has been working extremely well !! The electric bill has proven that point. For the time its been off line and we resorted to buying for the grid OUCH.$$$ and its been hot! so the heat pump has been flexing its muscles
Randen
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