Brake Igbt Test - GE AF-650 GP Operating Instructions Manual

6.2.3 Brake IGBT Test

This test can only be carried out on units equipped with a dynamic brake option.
1. Remove the safety covers to access the unit.
2. Note the position of the brake jumper bus bars prior to removal. The tops of the bus bars are connected to the motor lead bus bars as referred to in the
following test procedures.
3. Remove the brake jumper bus bars
Brake IGBT test part I
1. Connect the positive (+) meter lead to the brake resistor terminal R+ (82).
2. Connect the negative (-) meter lead to the brake resistor terminal R- (81).
The reading should indicate infinity. The meter may start out at a value and climb toward infinity as capacitance is charged within the frequency converter.
Brake IGBT test part II
1. Connect the positive (+) meter lead to the brake resistor terminal R- (81).
2. Connect the negative (-) meter lead to the brake resistor terminal R+ (82).
The reading should indicate a diode drop.
Brake IGBT test part III
1. Connect the positive (+) meter lead to the brake resistor terminal R- (81).
2. Connect the negative (-) meter lead to the negative (-) DC bus.
The reading should indicate infinity. The meter may start out at a value and climb toward infinity as capacitance is charged within the frequency converter.
Incorrect reading
An incorrect reading on any of the above tests indicates the brake IGBT is defective. Replace the brake IGBT per the disassembly procedure. The inverter module
must be removed to replace the IGBT brake.
High Power Service Manual for Unit Sizes 6x
6
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