Allen-Bradley 20F11NC037AA0NNNNN

Common Fault Codes

Fault Code 3

Power Loss – DC bus voltage dropped below the minimum threshold during operation, indicating an input power interruption or severe voltage sag.
Check input supply voltage and connections. Verify that input fuses and circuit breakers are intact. Inspect for loose wiring at the input terminals.

Fault Code 4

UnderVoltage – DC bus voltage is below the minimum acceptable level. This can occur during power dips or if the input voltage is out of specification.
Verify input line voltage is within the 342-528V AC range. Check for voltage sags on the supply. Inspect input wiring and connections.

Fault Code 5

OverVoltage – DC bus voltage has exceeded the maximum threshold, typically caused by regenerative energy from the motor during deceleration.
Increase deceleration time to reduce regenerative energy. Consider adding a dynamic braking resistor. Verify that the supply voltage is not above specification.

Fault Code 7

Motor Overload – The drive has detected that the motor has exceeded its thermal capacity based on the programmed motor overload parameters.
Check motor load conditions and reduce mechanical load if excessive. Verify motor nameplate data is correctly programmed in the drive parameters. Inspect motor for mechanical binding or overheating.

Fault Code 12

HW OverCurrent – A hardware-level overcurrent condition has been detected, indicating the output current has exceeded the drive's hardware protection threshold.
Check for short circuits in the motor cable or at the motor terminals. Verify motor insulation resistance. Inspect for damaged output wiring. If wiring is intact, the drive power section may require inspection or replacement.

Fault Code 29

Analog Input Loss – The analog input signal has been lost or has fallen below the configured minimum threshold, indicating a broken wire or signal source failure.
Check the analog input wiring and signal source. Verify that the signal is within the configured range. Inspect for broken or loose connections at the control terminal block.

Fault Code 33

Auto Restart Tries – The drive has attempted to automatically restart the maximum number of times following a fault without successfully clearing the fault condition.
Identify and resolve the underlying fault that triggered the auto-restart attempts. Clear the fault manually and investigate the root cause before re-enabling auto-restart.

Fault Code 81

Drive Overtemperature – The drive heatsink or internal temperature has exceeded the allowable limit, indicating insufficient cooling or excessive ambient temperature.
Check that cooling fans are operating correctly. Verify that ambient temperature is within specification. Clean any dust or debris from heatsink fins and ventilation openings. Ensure adequate clearance around the drive enclosure.