AB | 80026-044-06-R | POWER SUPPLY SWITCHING

Overview

• After isolating the drive from medium voltage, be sure that the
device, snubber circuit, sharing resistor and the fiber-optic signal
are not damaged.
• For multiple device faults, the risk of a line to line short exists, so
tests with medium voltage isolated should be attempted.
• Complete a resistance check on the rectifier, including the gatecathode resistance, the snubber and sharing resistors.
• Complete a firing check on the rectifier.
• Verify the snubber circuitry, and the sharing resistors.
• Verify fiber-optic integrity from SCRGD board transmitter to FOI
board receiver.
• Replace all faulty components.
• For nuisance faults, contact the factory about extending the
diagnostic delay.
NOTE: There is only the redundant option available on the Rectifier,
and only on 6P drives (SCR or PWM). You cannot have N-1 operation
on the rectifier since we cannot control the line voltage.