Allen-Bradley 20G1AND156JA0NNNNN

Common Fault Codes

Fault Code 2

Auxiliary Input fault. A digital input configured as an auxiliary input has opened, indicating an external fault condition.
Check the external device or circuit connected to the auxiliary input. Verify wiring continuity and confirm the external device is operating correctly before clearing the fault.

Fault Code 3

Power Loss fault. The drive detected a loss of input AC power or a significant voltage sag below the minimum threshold.
Check incoming AC supply voltage at all three phases. Inspect fuses, contactors, and supply cabling. Verify that supply voltage is within the rated input range of the drive.

Fault Code 4

UnderVoltage fault. DC bus voltage has dropped below the minimum operating level during run.
Measure incoming line voltage. Check for loose connections or phase loss. Verify that the supply transformer is adequately sized for the load.

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 detected sustained overcurrent conditions indicating the motor is thermally overloaded.
Reduce load on the motor or increase the motor overload parameter setting if the motor is rated for higher current. Check for mechanical binding or excessive load inertia.

Fault Code 12

HW OverCurrent fault. Hardware overcurrent protection has tripped due to output current exceeding the instantaneous hardware current limit.
Check for a short circuit or ground fault on the output wiring or motor windings. Verify motor insulation resistance. Reduce acceleration rate or increase current limit settings if appropriate.

Fault Code 29

Analog Input Loss fault. An analog input signal has fallen below the configured loss-of-signal threshold (e.g., 4 mA signal lost on a 4–20 mA input).
Check the analog signal source and wiring to the drive's analog input terminals. Verify the signal source is powered and functioning. Inspect for broken wires or loose terminal connections.

Fault Code 71

Adapter Communication Loss fault. The drive has lost communication with an installed option card or external communication adapter.
Check that the option card is fully seated in the option bay. Inspect the network cable and connections. Verify the network scanner or controller is active and the communication parameters match.