The items you list should not be drawing enough current to trip a 15 amp breaker. A 60 amp converter under full load should draw less than 8 amps and the fridge should draw around between 2 and 3.
Do you by any chance have a dual water heater, i.e. it runs off of propane and AC? If so there would be an additional switch in the bath area.
Is the breaker in question a GFCI breaker? If so you may have a hot to ground leak that is tripping the GFCI portion of the breaker. A common flaw is corrosion in the outside outlet box. A leak in the AC heater in the fridge is also a possibility.
Go to your trailer's AC breaker panel and turn all breakers off. Turn on shore power and wait long enough that you are sure it should trip. Turn the breakers on, one at a time, until you find the circuit that causes the trip.
"You cannot reason someone out of a position they have not been reasoned into"
Al, K5TAN and Missy, N4RGO WBCCI 1322
2002 Classic 30 Slideout -S/OS #004
2013 Dodge 2500 Laramie 4x4 Megacab Cummins