GE Industrial Solutions AF-600 FP High Power (460V_575V 150HP and above) - Manual (Page 48)

4.5 Fault Symptoms
4.5.1 No Display
The Keypad display provides two display indications. One by means of the
backlit LCD alphanumeric display. The other is three LED indicators lights near
the bottom of the Keypad. If the green power-on LED is illuminated but the
backlit display is dark, this indicates that the Keypad itself is defective and
must be replaced.
Be certain, however, that the display is completely dark. Having a single character in the upper corner of the Keypad or just a dot indicates that communications
may have failed with the control card. This is typically seen when a serial bus communication option has been installed in the frequency converter and is either
not connected properly or is malfunctioning.
If neither indication is available, then the source of the problem may be elsewhere. Proceed to the No Display test (6.3.1) to carry out further troubleshooting steps.
4.5.2 Intermittent Display
Cutting out or flashing of the entire display and power LED indicates that the power supply (SMPS) is shutting down as a result of being overloaded. This may be
due to improper control wiring or a fault within the frequency converter itself.
The first step is to rule out a problem in the control wiring. To do this, disconnect all control wiring by unplugging the control terminal blocks from the control card.
If the display stays lit, then the problem is in the control wiring (external to the frequency converter). All control wiring should be checked for shorts or incorrect
connections.
If the display continues to cut out, follow the procedure for No Display as though the display were not lit at all.
AF-650 GP and AF-600 FP High Power Service Manual
47
4