What was found
(CAN) ON ACFT SHORT COMING IN TESTING PROCEDURES WAS DISCOVERED WHILE FOLLOWING THE MM FOR THE ADJUSTMENT OF THE VOLTAGE REGULATORS FOR THE GENERATORS. WHEN THE ACFT IS EQUIPPED WITH VR-1010-24-1A VOLTAGE REGULATORS AS ALLOWED BY MFG SERVICE INSTRUCTION NR 0766-354, REV II THE TESTING PROCEDURE FOR THE OVERVOLTAGE IS NOT ACHIEVABLE. THE SOLID STATE VOLTAGE REGULATORS ARE NOT ADJUSTABLE TO A RANGE THAT WILL ADEQUATELY TEST THE OVERVOLTAGE RELAYS, OVER 31.5 VOLT. DURING A GROUND RUN AND ADJUSTMENT OF THE VOLTAGE REGULATORS, 1 REGULATOR FAILED AND CAUSED AN OVER VOLTAGE CONDITION. HAD THIS HAPPENED IN THE AIR IT COULD HAVE BEEN DANGEROUS. THEREFORE IT IS THIS TECH`S OPINION THAT THE TEST PROCEDURE FOR THE OVERVOLTAGE RELAY SHOULD BE CHANGED TO INCLUDE REMOVING AND BENCH TESTING THE OVERVOLTAGE RELAYS.