As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE TAXING FOR TAKEOFF THE CIRCUIT BREAKER POPPED. CREW RESET IT AND CONTIUNED THE FLIGHT. ABOUT 1 HOUR INTO THE FLIGHT THE CIRCUIT BREAKER POPPED AGAIN THE CREW RETURN TO THE AIRFIELD AND TERMINATED THE FLIGHT. THE TECH CHECKED THE WIRING WITH A VOLTAGE REGULATOR AND FOUND THE WIRING WAS FINE. REPLACED THE ELECTRIC FUEL PUMP.