I've got an AB 1336 AC drive that failed and had no DC bus voltage.
The DC bus fuse was fine. The incoming AC power was fine and the AC fuses were fine on the rectifier firing board.
We bench tested the SCR bridge for the rectifier each SCR in the device conducted when the gates were fired, and they all meggered fine.
We partially charged the capacitor bank with a crank megger, and they held a charge and seemed to discharge at a reasonable rate.
We replaced the rectifier firing board and the main control board, and we still have nothing. Could there be another condition that would keep the recifier from chargin the DC bus? Thanks.
The DC bus fuse was fine. The incoming AC power was fine and the AC fuses were fine on the rectifier firing board.
We bench tested the SCR bridge for the rectifier each SCR in the device conducted when the gates were fired, and they all meggered fine.
We partially charged the capacitor bank with a crank megger, and they held a charge and seemed to discharge at a reasonable rate.
We replaced the rectifier firing board and the main control board, and we still have nothing. Could there be another condition that would keep the recifier from chargin the DC bus? Thanks.