Allen Bradley PowerFlex 40P Drive Fault Codes List

Complete guide to Allen Bradley PowerFlex 40P fault codes. Troubleshoot positioning errors, F80 Encoder Loss, Safe-Off trips, and closed-loop control issues.

PowerFlex 40P Fault Codes Reference Table

Fault Codes	Cause & Solutions
F2 Auxiliary Input	Cause : Auxiliary input interlock is open. Solution: - Check remote wiring. - Verify communications programming for intentional fault.
F3 Power Loss	Cause: Excessive DC Bus voltage ripple. Solution: - Monitor the incoming AC line for low voltage or line power interruption. - Check input fuses. - Reduce load.
F4 UnderVoltage	Cause: DC bus voltage fell below the min value. Solution: Monitor the incoming AC line for low voltage or line power interruption.
F5 OverVoltage	Cause: DC bus voltage exceeded max value. Solution: - Monitor the AC line for high line voltage or transient conditions. - Bus overvoltage can also be caused by motor regeneration. - Extend the decel time or install dynamic brake option.
F7 Motor Overload	Cause: Internal electronic overload trip. Solution: - An excessive motor load exists. Reduce load so drive output current does not exceed the current set by parameter P033 [Motor OL Current]. - Verify A084 [Boost Select] setting
F8 Heatsink OvrTmp	Cause: Heatsink/Power Module temperature exceeds a predefined value. Solution: - Check for blocked or dirty heatsink fins. Verify that ambient temperature has not exceeded the rated ambient temperature. - Check fan.
F12 HW OverCurrent	Cause: The drive output current has exceeded the hardware current limit. Solution: - Check programming. - Check for excess load, improper A084 [Boost Select] setting, DC brake volts set too high or other causes of excess current.
F13 Ground Fault	Cause: A current path to earth ground has been detected at one or more of the drive output terminals. Solution: - Check the motor and external wiring to the drive output terminals for a grounded condition.
F29 Analog Input Loss	Cause: An analog input is configured to fault on signal loss. - A signal loss has occurred. - Configure with A122 [Analog In Loss]. Solution: 1. Check parameters. 2. Check for broken/loose connections at inputs.
F33 Auto Rstrt Tries	Cause: Drive unsuccessfully attempted to reset a fault and resume running for the programmed number of A092 [Auto Rstrt Tries]. Solution: Correct the cause of the fault and manually clear.
F38 Phase U to Gnd	Cause: A phase to ground fault has been detected between the drive and motor in this phase. Solution: - Check the wiring between the drive and motor. - Check motor for grounded phase. - Replace drive if fault cannot be cleared.
F39 Phase V to Gnd	Cause: A phase to ground fault has been detected between the drive and motor in this phase. Solution: - Check the wiring between the drive and motor. - Check motor for grounded phase. - Replace drive if fault cannot be cleared.
F40 Phase W to Gnd	Cause: A phase to ground fault has been detected between the drive and motor in this phase. Solution: - Check the wiring between the drive and motor. - Check motor for grounded phase. - Replace drive if fault cannot be cleared.
F41 Phase UV Short	Cause: Excessive current has been detected between these two output terminals. Solution: - Check the motor and drive output terminal wiring for a shorted condition. - Replace drive if fault cannot be cleared.
F42 Phase UW Short	Cause: Excessive current has been detected between these two output terminals. Solution: - Check the motor and drive output terminal wiring for a shorted condition. - Replace drive if fault cannot be cleared.
F43 Phase VW Short	Cause: Excessive current has been detected between these two output terminals. Solution: - Check the motor and drive output terminal wiring for a shorted condition. - Replace drive if fault cannot be cleared.
F48 Params Defaulted	Cause: The drive was commanded to write default values to EEPROM. Solution: - Clear the fault or cycle power to the drive. - Program the drive parameters as needed.
F63 SW OverCurrent	Cause: Programmed A098 [SW Current Trip] has been exceeded. Solution: - Verify connections between motor and load. - Check load requirements and A098 [SW Current Trip] setting.
F64 Drive Overload	Cause: Drive overload rating has been exceeded. Drive rating of 150% for 1 minute or 200% for 3 seconds has been exceeded. Solution: Reduce load or extend Accel Time.
F70 Power Unit	Cause: Failure has been detected in the drive power section. Solution: - Check that max ambient temperature has not been exceeded. - Cycle power. - Replace drive if fault cannot be cleared.
F71 Net Loss	Cause: The communication network has faulted. Solution: - Cycle power. - Check communications cabling. - Check network adapter setting. - Check external network status.
F80 SVC Autotune	Cause: The autotune function was either cancelled by the user or failed. Solution: - Restart procedure.
F81 Comm Loss	Cause: RS-485 (DSI) port stopped communicating. Solution: 1. If adapter was not intentionally disconnected, check wiring to the port. Replace wiring, port expander, adapters or complete drive as required. 2. Check connection. 3. An adapter was intentionally disconnected. 4. Turn off using A105 [Comm Loss Action].
F91 Encoder Loss	Cause: Requires differential encoder.One of the 2 encoder channel signals is missing. Solution: 1. Check Wiring. 2. If P038 [Speed Reference] = 9 “Positioning” and E216 [Motor Fdbk Type] = 5 “Quad Check” swap the Encoder channel inputs or swap any two motor leads. 3. Replace encoder.
F100 Parameter Chksum	Cause: The checksum read from the board does not match the checksum calculated. Solution: Set P041 [Reset To Defalts] to option 1 “Reset Defaults”.
F111 Enable Hardware	Cause & Solutions: 1. DriveGuard Safe-Off Option (Series B) board is installed and the ENBL enable jumper has not been removed. - Remove the ENBL enable jumper. - Cycle power. 2. DriveGuard Safe-Off Option (Series B) board has failed. - Remove power to the drive. - Replace DriveGuard Safe-Off Option (Series B) board. 3. Hardware Enable circuitry has failed. - Replace drive.
F122 I/O Board Fail	Cause: Failure has been detected in the drive control and I/O section. Solution: - Cycle power. - Replace drive if fault cannot be cleared.
F6 Motor Stalled	Cause: Drive is unable to accelerate or decelerate motor. Solution: - Increase P039…A067 [Accel Time x] or reduce load so drive output current does not exceed the current set by parameter A089 [Current Limit]. - Check for overhauling load.

 

How to Read PowerFlex 40P Faults

Troubleshooting the PowerFlex 40P requires checking both the drive status and the feedback loop integrity. Here is how to access the necessary data:

• Integral Keypad: The 4-digit LED display flashes “F” followed by the code. For positioning applications, the drive might not be faulted but simply “Holding” or waiting for a “Home” signal—check the status LEDs carefully.
• Fault History (d007 – d009):
  • d007: Most Recent Fault
  • d008: Fault 2
  • d009: Fault 3
• Encoder Diagnostics: If you suspect a feedback issue without a hard fault, check parameter d016 (Encoder Speed). If the motor is turning but this value reads “0”, your encoder signal is lost, which will eventually cause an F80 trip.
• Safe-Off Status: The PowerFlex 40P features a “Safe-Off” hardware input. If the yellow jumper on the control terminals is loose or the safety relay is open, the drive display may flash “STOP” or “SS” (Safe Stop) and will not start.

Frequently Asked Questions (FAQ)

Q: How do I fix the “F80 Encoder Loss” fault?

A: This is the most common fault specific to the PowerFlex 40P. It means the drive expects feedback but isn’t receiving it.

• Check the wiring at the encoder terminal block (Terminals 26-31).
• Verify the DIP switches for 5V vs. 12V/24V encoder power are set correctly for your device.
• Ensure parameter A169 (Encoder Config) matches your encoder’s line count (PPR).

Q: What is the difference between the PowerFlex 40 and 40P?

A: The “P” stands for Positioning. The 40P adds:

• Pulse Train/Encoder Input: Direct terminals for closed-loop speed control or basic position indexing.
• Safe Torque Off (STO): Compliant with EN954-1 Category 3.
• Positioning Logic: Internal parameters for StepLogic that include position hold and homing routines.

Q: Why won’t the drive run even though there are no faults?

A: On the PowerFlex 40P, check the Safe-Off inputs (Terminals 12 & 13 for the safety relay enable). Even if the standard Start command is given, the drive will not modulate if the Safe-Off circuit is open. The display will often indicate a “Non-Executable” state.