GE Industrial Solutions AF-600 FP High Power (460V_575V 150HP and above) User Manual
Page 99
Supply voltage
Supply voltage for the fans is from the soft charge card to power card connector MK106. First, verify the supply voltage is present as follows.
1.
Use a voltmeter to measure the AC phase to phase voltage at R, S, and T of power card connector MK106. It should equal main supply voltage applied
to frequency converter.
2.
If voltage is not present, ensure proper mains voltage is applied to frequency converter. Conduct Input Voltage test (6.3.2).
3.
If mains voltage is present at the input of the frequency converter but not at MK106 of the power card, conduct a static test of the soft charge fuses
(6.2.1).
4.
If voltage is present at MK106, check the voltage at the fan transformer read from connector CN2 located near the transformer. With a voltmeter, read
the AC voltage at CN2 pins 1 and 3. The voltage should correspond to the main mains voltage applied to the frequency converter.
5.
If voltage is not present, ensure jumpers are in place at power card connector FK103. Otherwise, connect an external source of power to terminal FK103
for fan supply voltage.
If the jumpers are in place or an auxiliary supply is connected and powered but no voltage is present at the fan transformer connector CN2, the power card is
likely defective. Replace the power card in accordance with the disassembly instructions in Section 7 or 8.
Transformer output
If the appropriate voltage is present at CN2 pins 1 and 3, next check the output of the transformer. Prior to making this test, ensure the fan transformer fuse is
good.
1.
With a voltmeter, measure mains voltage from CN2 terminal 1 to terminal 2. Voltage should equal 66% of main AC supply voltage (48% for frequency
converters 525–690 VAC) applied to frequency converter (or that of the auxiliary supply). If the voltage is incorrect, replace the fan transformer.
2.
If the voltage is correct, check the fan voltage supplied to the fans themselves. The voltage can be read at power card connector MK107 pins 8 and 11
with respect to pin 1. The voltage at pins 8 and 11 correspond to the fan's commanded speed: 200 VAC for low speed and 230 VAC for high speed.
If the correct voltage is available but the fan is not running, that fan is defective. If no voltage is available, verify that the fans should be running. If so, the power
card is defective. Replace the fan or power card in accordance with the disassembly instructions in Section 7 or 8.
Fan control circuit
To verify that the fan control circuit is receiving appropriate commands from the control card, the signal test board can be used to verify those signals.
1.
Remove power from the frequency converter and allow the DC bus to fully discharge.
2.
Install the signal test board into power connector MK104.
3.
Reapply power to the frequency converter.
4.
Connect the negative (-) meter lead of a voltmeter to signal board terminal 4 (common).
5.
With a positive (+) meter lead, check the signal at terminal 6 of the signal board. The meter should read zero (0) volts with the fans set to run, 5 VDC if
the control card has the fans set to off.
6.
Verify sequence of operation of the cooling fans to ensure they should be running. In addition, the signal board contains a fan test switch. When switched
on, fans should start and run at high speed.
The signals at terminals 5 and 10 of the signal board determine fan speed. See Section 9 for more on those signals. In addition, if a heatsink overtemperature trip
has occurred, the fans will automatically be switched to high speed.
Given the fact that the fans should be running, if the signal at terminal 6 is correct and the fan test switch activates the fan, the control card is defective. Otherwise,
the power card is defective. Replace the appropriate assembly in accordance with the disassembly instructions in Section 7 or 8.
AF-650 GP and AF-600 FP High Power Service Manual
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