GE Industrial Solutions AF-600 FP High Power Unit Sizes 6x - Manual (Page 94)

6.4 Module-level Static Test Procedures
6.4.1 Inverter Module
Heatsink Temperature Sensor Test
Remove the inverter module from the drive in accordance with disassembly procedures.
The temperature sensor is an NTC (negative temperature coefficient) device. As a result, high resistance means low temperature. As temperature decreases,
resistance increases. Each IGBT module has a temperature sensor mounted internally. The sensor is wired from the IGBT module to the gate drive card connector
MK100. The centre IGBT module is used.
On the gate drive card, the resistance signal is converted to a frequency signal. The frequency signal is sent to the power card for processing. The temperature
data is used to regulate fan speed and to monitor for over and undertemperature conditions.
1. Use ohmmeter set to read Ω.
2. Unplug connector MK100 on the gate drive card and measure the resistance across the cable leads.
The relationship between temperature and resistance is nonlinear. At 25 °C, the resistance will be approximately 5k Ω. At 0° C, the resistance will be approximately
13.7k Ω. At 60° C, the resistance will be approximately 1.5k Ω. The higher the temperature, the lower the resistance.
6.4.2 Rectifier Module
Heatsink Temperature Sensor Test
Remove the rectifier module from the drive in accordance with disassembly procedures.
The temperature sensor is an NTC (negative temperature coefficient) device. As a result, high resistance means low temperature. As temperature decreases,
resistance increases. The power card reads the resistance of the NTC sensor to regulate fan speed and to monitor for over temperature conditions.
1. Use ohmmeter set to read Ω.
2. Unplug connector MK103 on power card and measure across cable leads.
The full range of the sensor is 787 Ω to 10K Ω where 10K Ω equals 25°C and 787 Ω equals 95°C. The higher the temperature, the lower the resistance.
Soft Charge Rectifier Test
1. Remove the rectifier module from the drive in accordance with disassembly procedures.
2. Remove the power card mounting plate in accordance with disassembly procedures.
3. Disconnect the connector MK3 from each soft charge card.
Since the rectifier test requires the soft charge resistor to be in the circuit, verify the resistor is good before proceeding.
1. Measure the resistance between pins A and B of connector MK4 on the soft charge card. It should read 27 Ω (±10%) for 380–480 V frequency converters
or 68 Ω (±10%) for 525–690 V frequency converters. A reading outside this range indicates a defective soft charge resistor. Replace the resistor according
to the disassembly procedures. Continue tests.
Should the resistor be defective and a replacement not readily available, the remainder of the tests can be carried out by disconnecting the cable at connector
MK4 on the soft charge card and placing a temporary jumper across pins A and B. This provides a path for continuity for the remaining tests. Ensure any temporary
jumpers are removed at the conclusion of the tests. For the following tests, set the meter to diode check or Rx100 scale.
2. Connect the negative (-) meter lead to the positive (+) MK3 (A) (DC output to DC bus), and connect the positive (+) meter lead to MK1 terminals R, S, and
T in sequence. Each reading should show a diode drop.
3. Reverse meter leads with the positive (+) meter lead to the positive (+) MK3 (A). Connect the negative (-) lead to MK1 terminals R, S, and T in sequence.
Each reading should show open.
High Power Service Manual for Unit Sizes 6x
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