I installed a Kisae (note spelling) 55amp/2000 watt inverter
in 2014 and it worked fine for 6 months, then quit. I called the service
number for Canada
on their website (their service
technician is in Surrey, B.C.). He said the unit needed a software
update, which he could install if I brought in the unit, including the remote
. This proved impracticable and he ended up giving me a whole new unit, which has worked fine since. He was very helpful, and if you haven't already, you should phone/email him.
Also, I assume you have checked and reset if necessary the GFCI switch on the side of the case and on the A/C outlet on the end of the unit, and have checked that the 3 amp fuse is okay??