GE Industrial Solutions AF-600 FP High Power Unit Sizes 6x - Manual (Page 85)

Incorrect reading
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
Open (blown) input fuses or tripped circuit breakers usually indicate a more serious problem. Prior to replacing fuses or resetting breakers,
perform static tests.
If the Input Voltage Test was successful check for voltage to the control card.
6.3.5 Basic Control Card Voltage Test
1. If the Input Voltage Test was successful check for voltage to the control card.
If an external 24 VDC supply is used for control voltage, it would be likely for switch 4 on the control card to be open. This opens the common connection to
terminal 20. If this is the case, measure terminal 12 with respect to terminal 39.
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 out the customer connections.
2. Measure 10 V DC control voltage at terminal 50 with respect to terminal 55. 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 than continue. Remember to check out the customer connections.
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.
6.3.6 DC Undervoltage Test
The initial charge of the DC bus is accomplished by the soft charge circuit. If the DC bus voltage is below normal it would indicate that either the line voltage is
out of tolerance or the soft charge circuit is restricting the DC bus from charging. Conduct the input voltage test to ensure the line voltage is correct.
If excessive input power cycling has occurred, the PTC resistors on the soft charge card may be restricting the bus from charging. If this is the case, expect to read
a DC bus voltage in the area of 50 VDC.
High Power Service Manual for Unit Sizes 6x
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