Allen-Bradley 20G1AJC770JN0NNNNN

Common Fault Codes

Fault Code 2

Auxiliary Input fault. The auxiliary input interlock has opened, indicating an external fault condition has been signaled to the drive.
Check the external device or circuit connected to the auxiliary input terminals. Verify wiring integrity and confirm the external interlock device is functioning correctly before resetting the fault.

Fault Code 3

Power Loss fault. The drive detected a loss of input AC power or an input phase loss condition.
Check incoming AC supply voltage on all three phases. Inspect input fuses, disconnect, and supply wiring. Verify supply voltage is within the drive's rated input range.

Fault Code 4

UnderVoltage fault. DC bus voltage has dropped below the minimum acceptable threshold during operation.
Check input supply voltage for sags or interruptions. Inspect input line reactors or transformers. Verify that the supply capacity is adequate for the load being driven.

Fault Code 5

OverVoltage fault. DC bus voltage has exceeded the maximum allowable level, typically caused by regenerative energy from a decelerating load.
Increase deceleration time to reduce regenerative energy. Consider adding a dynamic braking resistor or an active front end. Check for overhauling load conditions.

Fault Code 7

Motor Overload fault. The drive's electronic overload protection has tripped due to sustained overcurrent condition in the motor.
Check motor load for mechanical binding or excessive load. Verify motor overload parameters are set correctly for the connected motor's nameplate ratings. Allow motor to cool before restarting.

Fault Code 12

HW OverCurrent fault. A hardware-level overcurrent condition was detected, indicating output current exceeded the drive's instantaneous hardware current limit.
Check for short circuits on the output wiring or motor windings. Verify motor insulation resistance. Inspect for sudden load impacts. Check that acceleration time is not too short for the load inertia.

Fault Code 33

Auto Restart Tries fault. The drive attempted to automatically restart after a fault the maximum number of times without successfully clearing the fault condition.
Identify and resolve the underlying fault that triggered repeated restart attempts. Review the fault queue log on the drive's HMI. Correct the root cause before manually resetting and restarting the drive.

Fault Code 81

Communication Loss fault. The drive lost communication with the controlling device over the configured network (e.g., EtherNet/IP, DeviceNet).
Check network cable connections and switch/hub integrity. Verify the controller is online and actively producing data. Review the drive's communication loss action parameter and network configuration settings.