GE Industrial Solutions AF-600 FP High Power (460V_575V 150HP and above) - Manual (Page 151)

To install the cable, first make sure the frequency converter is powered down and the DC bus is fully discharged.
1. For 4x-frame size units, follow the procedure in Section 7 for soft charge card removal and disengage the soft charge card far enough to disconnect
the cable plugged into the MK3.
2. For all frame sizes, disconnect the cable from the MK3 connector on the soft charge card and connect one end of the test cable into the MK3.
3. For 4x-frame size units, reinstall the soft charge card.
4. For all frame sizes, disconnect connectors MK100 and MK105 on the power card.
5. For all frame sizes, connect the free end of the test cable into MK105.
6. For all frame sizes, connect the SCR gate shorting plug into the cable that was removed from MK100.
When reapplying main input power to the frequency converter, the soft charge rectifier provides DC power to the power card. Testing with the use of the gate
signal board and the signal test board can now be carried out without the presence of DC bus voltage.
9.1.2 Signal Test Board (p/n 6KAF6H8437)
The signal test board provides access to a variety of signals that can be helpful
in troubleshooting the frequency converter.
The signal test board is plugged into power card connector MK104. Points on
the signal test board can be monitored with or without the DC bus disabled.
In some cases, the frequency converter will need the DC bus enabled and
operating a load to verify some test signals.
The following is a description of the signals available on the signal test board.
Section 6 of this manual describes when these tests would be called for and
what the signal should be at that given test point.
130BX66.10
Illustration 9.4: Signal Test Board
9.1.3 Signal Test Board Pin Outs: Description and Voltage Levels
The tables on the following pages list the pins located on the signal test board. For each pin, its function, description, and voltage levels are provided. Details on
performing tests using the test fixture are provided in Section 6 of this manual. Other than power supply measurements, most of the signals being measured are
made up of waveforms.
Although in some cases, a digital voltmeter can be used to verify the presence of such signals, it cannot be relied upon to verify that the waveform is correct. An
oscilloscope is the instrument prefered. However, when similar signals are being measured at multiple points, a digital voltmeter can be used with some degree
of confidence. By comparing several signals to each other, such as gate drive signals, and obtaining similar readings, it can be concluded each of the waveforms
match one another and are therefore correct. Values are provided for using a digital voltmeter for testing as well.
Pin No. Schematic
Acronym
Function Description Reading Using a Digital Voltmeter
1 IU1 Current sensed,
U phase, not condi-
tioned
Approx 400 mv RMS @100% load
.937 VACpeak @ 165% of CT current rating. AC
waveform @ output frequency of the frequency
converter.
AF-650 GP and AF-600 FP High Power Service Manual
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