GE Industrial Solutions AF-600 FP High Power (460V_575V 150HP and above) - Manual (Page 88)

Incorrect reading
Open (blown) input fuses or tripped circuit breakers usually indicate a more serious problem. Prior to replacing fuses or resetting breakers,
perform static tests described in section 6.2.
An incorrect reading here requires that the main supply be investigated further. Typical items to check would be:
Open (blown) input fuses or tripped circuit breakers
Open disconnects or line side contactors
Problems with the power distribution system
If the Input Voltage Test was successful check for voltage to the control card.
6.3.3 Basic Control Card Voltage Test
1. Measure the control voltage at terminal 12 with respect to terminal 20. The meter should read between 21 and 27 VDC.
An incorrect reading here could indicate the supply is being loaded down by a fault in the customer connections. Unplug the terminal strip and repeat the test. If
this test is successful, then continue. Remember to check the customer connections. If still unsuccessful, proceed to the Switch Mode Power Supply (SMPS) test.
2. Measure the 10 V DC control voltage at terminal 50 with respect to terminal 55. The meter should read between 9.2 and 11.2 VDC.
An incorrect reading here could indicate the supply is being loaded down by a fault in the customer connections. Unplug the terminal strip and repeat the test. If
this test is successful, then continue. Remember to check the customer connections. If still unsuccessful, proceed to the SMPS test.
A correct reading of both control card voltages would indicate the Keypad or the control card is defective. Replace the Keypad with a known good one. If the
problem persists, replace the control card in accordance with the disassembly procedures in Section 7 or 8.
6.3.4 Switch Mode Power Supply (SMPS) Test
The SMPS derives its power from the DC bus. The first indication that the DC bus is charged is the DC bus charge indicator light located on the power card being
lit. This LED however can be lit at a voltage still to low to enable the power supplies.
First test for the presence of the DC bus.
1. Using a voltmeter, read DC bus voltage at power card connector MK105 (A) with respect to MK105 (B). The meter should indicate approximately 1.35 x
AC input voltage to the frequency converter.
2. If the voltage is correct, proceed to set 3. If voltage is present but out of range, proceed to DC Undervoltage test. If voltage is at zero, proceed to Zero
DC Bus Voltage test.
3. Test the remaining power supplies. Insert the signal test board into the power card connector MK104.
4. Connect the negative (-) meter lead to terminal 4 (common) of the signal board. With a positive (+) meter lead, check the following terminals on the signal
board.
Terminal Supply Voltage Range
11 +18V 16.5–19.5 VDC
12 -18V -16.5–-19.5 VDC
23 +24V 23–25 VDC
24 +5V 4.75–5.25 VDC
In addition, the signal test board contains three LED indicators that indicate the presence of voltage as follows:
Red LED +/- 18VDC supplies present
Yellow LED +24VDC supply present
Green LED +5VDC supply present
AF-650 GP and AF-600 FP High Power Service Manual
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