Allen-Bradley 20G11NC3P5AA0NNNNN

Common Fault Codes

Fault Code 12

HW OverCurrent – The drive output current has exceeded the hardware overcurrent trip threshold.
Check for a short circuit at the drive output or motor terminals. Verify motor and cable insulation resistance. Reduce acceleration rate or check for mechanical overload on the motor.

Fault Code 13

Ground Fault – Excessive current is detected flowing to ground at the drive output.
Inspect motor cables and motor windings for insulation breakdown to ground. Disconnect the motor and run the drive unloaded to isolate whether the fault is in the cable or motor.

Fault Code 3

Power Loss – DC bus voltage dropped below the minimum acceptable level during operation.
Check input supply voltage for sags or interruptions. Verify input fusing and contactor operation. Inspect input power connections for loose terminals.

Fault Code 4

UnderVoltage – The DC bus voltage has fallen below the undervoltage trip level.
Measure incoming AC supply voltage and verify it is within the drive's rated input range. Check for voltage drops under load and inspect supply transformer capacity.

Fault Code 5

OverVoltage – The DC bus voltage has exceeded the overvoltage trip threshold, typically caused by regenerative energy from the motor.
Increase deceleration time to reduce regenerative energy. Consider adding a dynamic braking resistor or an active front end if regeneration is frequent. Check supply voltage for overvoltage conditions.

Fault Code 7

Motor Overload – The drive's electronic overload protection has detected sustained overcurrent indicative of motor thermal overload.
Verify motor FLA setting in the drive parameters matches the motor nameplate. Check for mechanical overload or excessive duty cycle. Allow motor to cool before restarting.

Fault Code 29

Analog Input Loss – An analog input configured for a 4-20 mA signal has detected a signal below 2 mA, indicating a broken wire or failed signal source.
Check wiring continuity on the analog input circuit. Verify the signal source device is powered and functioning. Confirm parameter settings for analog input loss action are configured correctly.

Fault Code 71

Safe Torque-Off (STO) – The safe torque-off function has been activated, removing gate firing signals from the output power devices.
Verify that the STO input signals are correctly applied and that the safety circuit is in the correct state for operation. Check STO wiring and the safety relay or controller providing the STO signal.