Where you running this off of a generator or power off the pole?
also check to see if any of the wires are nicked or touching which would also cause it to keep tripping the breaker.
Did you have anything else running in the camper or just the hot water heater?
I have camped at a site that kept popping the 30 amp breaker at the pole so I switch from 50 amp to 30 amp and never had a problem with the outside popping the breaker.
2011 Rockwood Mini Lite 2306 - Matt
2004 Dodge Ram 1500 Qaud Cab 4x4 with 35" tires and 3.92 gears, Dynatech Longtube Headers & Fabtech 6" lift + Superchips with shift Tuning
Nights Camped 2011 (37) - 2012 (16)-2013 (2) -2014 (5) -2015(0)
USMC 91 - 95 - F/A-18 Aviation Ordnance