4-12 Controller Troubleshooting
TP-5672 11/95
System-Status, System-Alert
For location of pushbuttons, switches, LEDs, and keys
referred to in this section, see Figure 2-1.
If the System-Status, System-Alert LED is flashing,
check the LCD for an error message. If the
System-Status, System-Alert LED is flashing, but no
error message appears on the LCD, the status panel is
defective. Replace the logic board assembly.
The following sections will cover the different error
messages encountered when the System-Status,
System-Alert LED is flashing.
Contactor Position Fault Error
Messages
The auxiliary-switch (AUX-SWITCH) fault error occurs
when the position of the contactor does not match the
position that the logic controller last placed the contactor
in. The double auxiliary-switch (DBL AUX-SW) fault error
occurs when two contactor positions are detected
simultaneously. If either of these error messages
appears on the LCD, perform the following steps. See
Figure 4-8.
P1-14
P1-10
P1-13
Closed in Normal
Closed in Emergency
560448
Figure 4-8. Wiring Diagram— Auxiliary-switch fault
and double auxiliary-switch fault
error message
Check the continuity of the contactor by performing the
following three steps:
1. Disconnect the 24-pin plug to the logic controller
assembly.
2. While the contactor is in the NORMAL position,
connect one test lead of an ohmmeter to the
contactor side of P1-12. Connect the other test lead
to the contactor side of P1-4. Note the resistance.
3. While the contactor is in the EMERGENCY
position, connect one test lead of an ohmmeter to
the contactor side of P1-16. Connect the other test
lead to the contactor side of P1-8. Note the
resistance.
4. If the resistance in either case was high, there is an
open circuit. Verify correct wiring.
5. Check the auxiliary switches on the contactor.
The following steps check proper operation of the
controller.
6. Connect the positive lead of a 12-24 volt DC power
source to TB-DC1-29. Connect the negative lead of
the power source to TB-DC1-34. See Appendix B
Figure B-9 for location of TB-DC1 and other power
supply board components referred to in this section.
7. Connect P1-12 to P1-4. Press the RESET MENU
key. If the Contactor-Position, Normal LED is not
on, or if the System-Status, System-Alert LED is still
on, replace the power supply board.
8. Connect P1-16 to P1-8. Press the RESET MENU
key. If the Contactor-Position, Emergency LED is
not on, or if the System-Status, System-Alert LED is
still on, replace the power supply board.
Transfer Hang Error Message
A Transfer Hang error occurs when the controller issues
a transfer command, but a transfer is not detected.
If TRANSFER HANG ERROR appears on the LCD,
check for a binding contactor and check the contactor
bridge rectifier. See the Contactor Service Manual.
Power-Down Error Message
A POWER-DOWN ERROR indicates there was a loss of
AC power for a period of time. If the POWER-DOWN
ERROR message does not appear regularly on the LCD,
press the RESET MENU key, and set the time and the
date. Press the RESET MENU key and then the ENTER
key to store the setpoints. If the POWER-DOWN
ERROR message does appear regularly on the LCD,
perform the following two steps.
1. If the ambient temperature is less than 20 degrees
Fahrenheit, install a battery backup on the logic
board.
