Here is the inverter I have :
http://www.xantrex.com/power-products/inverter-chargers/freedom-458.aspx
Kinda hidden from view by the black cover is what looks like a 20 AMP fuse. It is white with 20 on it. I took the nut off it, but it didn't seem like it wanted to come out. I didn't force it. It has always been lose and didn't feel like it was anything to reset. It's always been that way.
One of the first things I did 3 weeks ago was unplug everything. ( the microwave, water heater, two on the fridge ). It didn't make any difference. The only things I didn't unplug were the front and bedroom TVs due to their un-accessibility.