TP-6322 9/0424 Section 4 Troubleshooting
4.7.5 NR/ER Relays, Coils, and
Controller Circuitry
Use the following steps to troubleshoot controller
circuits when voltage is not appearing on terminals AC1
and AC2 of the bridge rectifier BR to energize the
solenoid when a transfer is supposed to occur.
NR/ER Relay, Coil, and Controller Circuit
Troubleshooting
1. Disconnect all power sources.
2. Check that the jumper on terminals CRB and
CRBD (TB4-1 and TB4-2) is installed. If not,
reinstall a permanent jumper wire between these
terminals and test the system.
3. Manually operate the contactor to the normal
position and check for continuity between
terminals J1-7 and J1-10 on the controller
assembly. There should be no connection, replace
the NR relay if there is. See Figure 4-5.
4. Coil-clearing contact SCE should be closed.
Check for continuity across contact SCE between
coil terminal 7 and neutral. Check the contactor
wiring harness and connections or replace
coil-clearing c ontact SCE if there is no continuity.
SeeFigure4-5.
5. Manually operate the contactor to the emergency
position.
6. Coil-clearing contact SCN should be closed.
Check for continuity across SCN between coil
terminal 3 and neutral. Check the contactor wiring
harness and connections or replace coil-clearing
contact SCN if there is no continuity. See
Figure 4-6.
7. Apply the normal power source. The NA LED
should light. If the NA LED does not light, see
Section 4.10.
8. When the NA LED lights, wait for TDEN, listen to
the NR relay energize, and observe the NR LED. If
120 volts is not applied between terminals J 1-15
and neutral and the contactor does not transfer to
the normal source, check the following. See
Figure 4-7.
a. If the NR LED does not light, replace the
controller assembly.
b. If the NR LED lights but the NR relay does not
energize, replace the NR relay. If the
replacement NR relay does not cause 120 volts
to be applied between terminals J1-15 and
neutral, replace the controller assembly.
9. If the NA LED is lit, NR is energized, and 120 volts
appears between J1-15 and neutral but the
contactor does not transfer to the normal position,
check the contactor wiring harness and
connections to terminals 3 and 4 on the CN coil.
Replace the CN coil if the wiring harness and
connections are good.
10. When the contactor transfers the load to the normal
power source, disconnect the normal source and
allow the generator set to start.
11. When the generator starts the EA LED should light.
If the EA LED does not light, see Section 4.9.
12. When the EA LED lights, wait for TDNE, listen to
the ER relay energize, and observe the ER LED. If
120 volts is not applied between terminals J1-6 and
neutral and the contactor does not transfer to the
emergency source, check the following. See
Figure 4-8.
a. If the ER LED does not light, replace the
controller assembly.
b. If the ER LED lights but the ER relay does not
energize, or if the ER relay energizes and the
NR relay was replaced, replace the ER relay.
c. Replace the NR or ER relay if it has not been
replaced already. It is difficult to access the
contacts to determine the faulty relay in-circuit.
13. If voltage appears between terminals J1-6 and
neutral but the contactor does not transfer to the
emergency position, check the contactor wiring
harness and connections to terminals 7 and 8 on
coil CE. Replace the CE coil if the wiring harness
and connections are good.
4.8 Controller Operation
Follow this section to check the controller’s automatic
operation sequence including engine starting, time
delays, contactor operation, and LEDs.
Controller Operation Test
1. Disconnect all power sources for at least five
minutes.
2. Manually operate the contactor to the normal
position.
3. Disconnect the exerciser switch wiring harness
from connector P2 on the controller assembly.
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