The refrigerator is running on the inverter even as I type this. It seems to actually work!
What remains to be seen is how long it can run and what will be involved in bringing the batteries back up to charge. There has been direct sun on the panels all afternoon. But as the sun is getting lower there are also some clouds on the horizon. With the panels shaded we are no doubt taking most of the power needed from the batteries now instead of directly from the panels. I don’t know how long they will hold out in actual use.
The main point of this test, however, is that I have now proven that I can run the fridge on my back-up system. * does happy dance * :-)
UPDATE: Just before 11 PM local time I put the fridge back on grid power.
Not because of any problem with running it from the batteries. The charge controller is still showing 12.3 volts in the batteries. The inverter even handled the start-up load from the defrost cycle which pushes its limits according to my appliance load tester.
And not because of any problem with the fridge itself. It was running fine with the modified sign wave power supplied by the inverter. We didn’t do anything different in how we accessed the fridge either. It was a totally normal Saturday afternoon here’bouts.
The only reason I unplugged from the inverter was so I could get the power cord out of the way to properly close the hall window. The workshop/pantry on our enclosed porch where the power equipment lives is unheated and it’s cold out there tonight! With the thermostat about four feet away from a jalousie window that was open enough let a heavy duty extension cord pass through, the heater was running more than it should have been.
I could have stuffed a blanket in the window to solve that problem, but I decided to end the test instead. I think we ran long enough to prove that it works. This problem with the window, that I was expecting all along, will be eliminated when I run a line from the inverter under the house in the crawl space and up the wall to a switch that will allow me to toggle back and forth between grid power and the inverter without even unplugging the fridge from the wall. I’ll do that on an individual basis for each appliance I decide to power from our solar system. I just had to run this test before I invest in upgrading the houses wiring to do that. Now that I know that it really does work I feel a lot more confidant in spending the cash to bring it to that next level.
All in all I would call this test a Resounding Success!