What was found
DURING THE CROSSFEED CHECK AT CRUISE, THE CROSSFEED SWITCH WAS PLACED IN THE OPEN POSITION WITH NORMAL INDICATIONS. WHEN PLACED BACK IN THE CLOSED POSITION DURING THE CYCLE, THE X-SWITCH WAS INADVERTENTLY PLACED BACK IN THE OPEN POSITON CAUSING THE CROSSFEED BREAKER TO POP. MAINTENANCE WAS ADVISED AND BREAKER WAS RESET. CROSSFEED VALVE OPERATED NORMAL. ACFT GROUNDED. GVI OF FUEL CROSSFEED VALVE, NO DEFECTS NOTED. MANUALLY CYCLED CROSSFEED VALVE OPEN AND CLOSED, NO DEFECTS NOTED. CYCLED FUEL CROSSFEED VALVE OPEN AND CLOSED ELECTRICALLY SEVERAL TIMES, NO DEFECTS NOTED. AMM FIM 28-22 TASK 808.