Originally Posted by Ron in BC
I have not doubt it'll be fine.
OK, I took a bullet for the team and have to eat my words:
Actually I meant because I've had previous CT inverters and they worked fine I wasn't worried about testing my new one after it was installed. Not that I knew for sure that it'd be OK with a 1500 watt load.
I don't have a transfer switch installed yet so I substituted a 1500 watt heater. Instant alarm. Switched to the 900 watt setting and ran it for 2 minutes. Starting voltage was 12.5 and ending voltage was 12.5. Average draw seemed to be about 80 amps. So I'm reasonably confident that the microwave will be OK but I'll make up a jumper and test it sooner than later.
Did ETI install your inverter? If so, I would look at how they connected the negative lead.
One thing I don't like about ETI 12 volt wiring is that they run the negative cable from the battery to the frame. Then, about a foot away, they connect the ground from the converter to the frame. To me that's very poor. My view is the negative cable should be continuous. Each terminal connected to the frame is a possible source of corrosion and high resistance.
So my question is; is your inverter negative cable continuous from the battery to the inverter?