Many thanks to all for your input. The house breaker did not trip and the loads supported by the external power work fine.
As explained by many, the power sharing system is very cleverly designed. My 2000 watt inverter handles all the kitchen appliances fine individually. The external power supplies primarily the heavy loads like A/C, washer/dryer, water heater and refrigerator, all of which are never powered by the inverter. When adequate power is available the inverter passes the external power through to the components normally powered by the inverter.
I will look for the inline fuse and test it. My inverter has four output breakers, none of which are tripped. My next step will be to enter the output breaker panel and check for inverter output. Next to contact the manufacturer for addiction suggestions.
I'm also guessing that my inverter needs overhaul or replacement because its no/low load output voltage is 130 VAC or greater.
Another item that still puzzles me, do GFI receptacles require power to trip and reset?