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Rockwell Automation Publication 150-UM009E-EN-P - August 2021
Chapter 4 Troubleshooting
Troubleshooting Steps
4
Phase Loss/
Open Load
• Missing Supply Phase.
• Missing or unable to detect motor connection.
• Check for open line (open fuse).
• Check for incorrect wiring to load.
• Verify proper operation of the fault contactor.
• Verify connection type to motor (line or Delta).
• Ensure product is sized correctly for motor.
5
Phase Imbalance
• Unbalanced Phase Currents (> 65% differential).
• Incoming line voltage problem.
• Check motor current in each phase to verify imbalance. Motor
current imbalance can indicate potential motor problem.
6
Shorted SCR
• Shorted SCR.
• Welded or latched bypass contactor.
• Verify connection type (line or Delta) and verify setting.
• Perform continuity check across power poles (L1 – T1, L2 – T2,
L3 - T3). Measurements should exceed 10 kΩ. For best results,
remove line and load motor connections.
• Cycle power to device and attempt to restart. If fault persists,
replace device.
7
Test
• Intended operation.
• Reset fault.
12
Check Sum
• Internal software corruption.
• Replace device.
Table 18 - LED Fault Indication & Diagnostics (Continued)
Flashes
Fault Type
Possible Fault Explanations
Possible Solutions
Table 19 - Troubleshooting Steps
Control
Device Status
Solution
Prestart - no start command given but
device is faulted.
LED Flashing
• Reset fault.
• Allow device to cool (overload or SCR over temp). Reset fault.
• Cycle power to device.
Motor fails to start after start command
given.
LED Off
• Check control power.
• Check control circuit connections.
LED ON
• Verify proper operation of fault contactor or isolation devices.
• Check connections to the motor.
• Verify line power and frequency are within specifications.
LED Flashing
• See
for information related to specific fault codes.
Motor attempts to start after start command
is given, but fails to reach an up-to-speed
condition.
LED ON
• Verify proper operation of the fault contactor or isolation devices.
• Verify line power and frequency are within specifications.
• Try increasing the initial torque or current limit setting.
LED Flashing
• See
for information related to specific fault codes.
Motor stops abruptly and fails to restart.
LED Off
• Check for a blown fuse or tripped circuit breaker.
• Ensure the control power and start command are present.
• Verify proper operation of the fault contactor or isolation devices.
LED ON
• Verify proper operation of the fault contactor or isolation devices.
LED Flashing
• See
for information related to specific fault codes.
Fault contactor fails to close when power
is applied.
All Conditions
• Verify wiring to the coil. The contactor should close when power is applied to the controller.
• Verify voltage across the coil (A1 to A2).
• Check the resistance of the coil. Replace, if measured open.
• Verify internal contact of the controller (terminals 97/98) are properly changing state. Replace the
controller if the contact does not operate correctly.