What was found
(CAN) AFTER TAKEOFF, THE GROUND REFUEL AND FUEL TANK FILL VALVE AND BATTERY BUS SENSING CIRCUIT BREAKERS TRIPPED. ALSO, BATTERY BUS OFF LIGHT CAME ON. BOTH CIRCUIT BREAKERS RESET AND TRIPPED AGAIN, AIRCRAFT RETURNED. FOUND WIRE CHAFED AT EXTERNAL REFUEL PANEL. REPAIRED.