If you can get one of those AC proximity tester from any home center, they're great for tracing faults in AC lines. Before you plug in your "shore" power cord, turn off all the lights, appliances, converter and accessories. Now once plugged in, use that tester to see if power is going to the 30A main breaker which Maineah have mentioned. If you have power on the main, check each breaker if it's getting distributed to all. If everything is good there, switch on your appliances and accessories one at a time to find the offending one. I had this kinda problem before, and what happened was the old converter/charger combined with a dying coach battery was drawing too much current from our outside AC outlet which tripped the house breaker constantly.