VAMP - Grid Interface and GRID TANK INPUT VOLTAGE CORRECTION

Service note 4680: VAMP - Grid Interface and GRID TANK INPUT VOLTAGE CORRECTION Grid/Bias interface Board 2137893, Grid tank 2127280-2 Frequent grid tank failures. Correct the input voltage range for Grid tank. Service note 4680: VAMP - Grid Interface and GRID TANK INPUT VOLTAGE CORRECTION Grid/Bias interface Board 2137893, Grid tank 2127280-2 Frequent grid tank failures. Correct the input voltage range for Grid tank. PROBLEM The Grid/Bias interface Board voltage adjustment is required in the MPPU GENERATOR DISASSEMBLY/RE-ASSEMBLY documentation with 10% tolerance (SM 2323207-100 - Job Card DR007 Section 13 and schematic 2137893.SCH). The grid needs exactly 36 Volts, over voltage could induce premature failure of Micro Grid. SOLUTION Adjust the G1 voltage value of the on the Grid/Bias interface PCB MPPU1 A5 A13 to exactly 36V (tolerance +/- 0.8%). PROCEDURE 1 CHECK THE G1 VOLTAGE Check the G1 voltage value of the on the Grid/Bias interface PCB MPPU1 A5 A13. Measurement is to be done between TP4 and TP3 of this board. 2 ADJUST G1 VOLTAGE TO 36V The G1 nominal voltage is U = 36V. The voltage limits are 35,7V and 36,3V (tolerance is +/- 0.8%). The adjustment has to be carried out with the power supply potentiometer, on the Grid/Bias interface PCB. Note: If you are changing the micro-grid, pursue with the Job Card DR17-108. 3 MARK "MODIFIED PER SN 4680", • On the changed DR007 Job Card, • On the Revision History 4 INSERT A COPY OF THIS SERVICE NOTE IN THE CHANGED DIRECTIONS.