Allen-Bradley PowerFlex 525 Fault Codes: Complete Troubleshooting Guide

How Allen-Bradley PowerFlex 525 Fault Codes Work

Fault codes are diagnostic messages that trigger when the drive detects unsafe or abnormal conditions.

• Type 1 (Auto-reset) – These may clear automatically when conditions improve (for example, undervoltage during a line dip).
• Type 2 (Non-resettable) – These require action: fix the cause, then manually reset or power cycle.

Pro tip: Always address the root cause. Simply clearing a code without fixing the problem can lead to repeated trips and costly downtime.

• Verify incoming AC line power stability and proper grounding.
• Confirm realistic parameter settings (accel/decel, current limits).
• Check cooling and airflow in the enclosure.
• Inspect motor and control wiring for loose or damaged connections.

The Most Common PowerFlex 525 Fault Codes (and How to Fix Them)

Power & Voltage Faults

• F003 – Power Loss
  Cause: Loss of incoming AC line or single-phase condition.
  Fix: Monitor AC line stability, inspect fuses, reduce load.
  Context: Common during power sags or if a fuse blows on one phase.

• F004 – Undervoltage
  Cause: DC bus voltage fell below minimum.
  Fix: Check supply for dips or interruptions; stabilize the source.
  Context: Often happens when large motors or welders share the same feed.

• F005 – Overvoltage
  Cause: DC bus voltage exceeded maximum. Usually from regeneration or line surges.
  Fix: Increase decel time, add a dynamic braking resistor, inspect AC line for surges/transients.
  Context: Shows up frequently when high-inertia loads decelerate too quickly.

Motor & Load Faults

• F006 – Motor Stalled
  Cause: Drive can’t accelerate or decelerate the motor.
  Fix: Increase accel time (P041, A442–A446), reduce load, inspect mechanics for binding or jams.
  Context: Typical in conveyors with heavy loads or jammed material.

• F007 – Motor Overload
  Cause: Motor drawing more current than rated; internal overload protection tripped.
  Fix: Reduce load, verify P033 (Motor OL Current), confirm boost settings (A530).
  Context: Common when a machine is over-tensioned or a pump runs dry.

• F015 – Load Loss
  Cause: Output torque current dropped below programmed threshold for too long.
  Fix: Check motor-to-load coupling; adjust A490 (Load Loss Level) and A491 (Load Loss Time).
  Context: Often seen with broken couplings, belts, or no-load running.

• F064 – Drive Overload
  Cause: Drive rating exceeded.
  Fix: Reduce load or extend accel time; evaluate if the drive is undersized for the application.

Thermal Faults

• F008 – Heatsink Overtemp
  Cause: Heatsink or power module too hot.
  Fix: Clean heatsink fins, confirm fan operation, reduce ambient temperature / improve ventilation.
  Context: Very common in dusty or hot enclosures.

• F009 – Control Module Overtemp
  Cause: Control electronics overheating.
  Fix: Improve airflow, remove obstructions, ensure enclosure fans are working.

Current & Ground Faults

• F012 – Hardware Overcurrent
  Cause: Drive output current exceeded hardware limit.
  Fix: Reduce load; verify programming; check wiring, boost (A530), and DC brake settings.
  Context: Frequent during sudden load spikes.

• F013 – Ground Fault
  Cause: Current path detected to earth ground at output terminals.
  Fix: Inspect motor insulation and wiring; correct any grounded conditions.
  Context: A critical safety fault — investigate thoroughly.

• F038–F043 – Phase-to-Ground / Phase-to-Phase Faults
  Cause: Short detected between motor phases or a phase to ground.
  Fix: Inspect motor and cable insulation and terminal connections; replace the drive if damage cannot be cleared.
  Context: Usually caused by damaged motor windings or cables.

Communication & Network Faults

• F071 – DSI Network Loss
  Cause: Modbus/DSI communications interrupted.
  Fix: Cycle power; check cabling and comm settings; verify master status.

• F072 – Option Card Network Loss
  Cause: Network option card lost communication.
  Fix: Reseat card; check external network; replace wiring or the card if needed.

• F073 – Embedded EtherNet/IP Loss
  Cause: Embedded adapter dropped connection.
  Fix: Verify IP settings, cable integrity, switch health; consider C125 (Comm Loss Action).
  Context: Common when networks are congested or cables are loose.

• F081–F083 – Communication Loss (DSI / Option / Embedded)
  Cause: Internal/external communications interrupted.
  Fix: Inspect cabling, grounding, and settings; reinstall option card if needed; replace damaged components.

Safety & Control Faults

• F002 – Auxiliary Input Trip
  Cause: External trip command triggered.
  Fix: Verify remote wiring and communications logic; ensure any intentional trip logic is understood.
  Context: Typical when safety relays or e-stops are triggered.

• F059 – Safety Open
  Cause: Safety inputs not enabled.
  Fix: Check safety terminals (S1, S2, S+); verify jumpers if safety is not used; confirm t105 (Safety Open Enable) configuration.

• F091 – Encoder Loss
  Cause: Encoder channel signal missing.
  Fix: Inspect wiring; swap channel leads if required; replace encoder if faulty.
  Context: Critical in positioning systems like hoists or indexing conveyors.

Hardware & Firmware Faults

• F048 – Parameters Defaulted
  Cause: Parameters reset to defaults (commanded or EEPROM event).
  Fix: Reprogram required values; clear fault or cycle power.

• F070 – Power Unit Failure
  Cause: Failure in the drive power section.
  Fix: Check ambient temperature; cycle power; replace drive if the fault persists.

• F100 / F101 – Parameter Storage / Checksum Error
  Cause: Parameter storage corrupted or external storage failed.
  Fix: Use P053 (Reset to Defaults); re-enter parameters; restore from backups.

• F105–F109 – Control/Power Module Mismatch or Connection Error
  Cause: Incompatible or incorrectly recognized modules.
  Fix: Reset power; verify proper module pairing; replace control module if needed.

• F114 – Microprocessor Failure
  Cause: Internal CPU fault.
  Fix: Cycle power; replace control module if unresolved.

• F122 – I/O Board Failure
  Cause: Control or I/O hardware fault.
  Fix: Cycle power; replace control module or drive if the fault persists.

• F125 / F127 – Flash Update Required
  Cause: Firmware corrupt or mismatched (including DSI-only backup firmware state).
  Fix: Perform a proper firmware flash update (per OEM procedure) to load a valid set.

• F126 – Non-Recoverable Error
  Cause: Critical internal firmware or hardware error; drive stopped and reset automatically.
  Fix: Clear fault or cycle power; if recurring, replace drive or control module.

Preventing Recurring Faults

• Cooling: Keep heatsinks and fans clean; monitor ambient temps.
• Power Quality: Use surge protection; maintain proper grounding and shielding.
• Parameters: Set realistic accel/decel times and current limits for your application.
• Wiring: Inspect cables for wear, insulation breakdown, or loose terminals.
• Firmware: Keep firmware current and consistent across drives and modules.

When to Repair vs. Replace

Some issues — like repeated Power Unit Failures (F070), Microprocessor Failures (F114), or Non-Recoverable Errors (F126) — often indicate hardware damage that’s not worth chasing. In these cases, replacing the drive is typically the fastest and most cost-effective path back to production.

That’s where Industrial Automation Co. can help:

• Thousands of in-stock PowerFlex 525 units and parts
• Same-day shipping to reduce downtime
• Free technical support to help diagnose faults before you buy

Shop PowerFlex 525 Drives Now

Not sure which option you need? Contact us for support.

Full Allen-Bradley PowerFlex 525 Fault Code Guide

This article covers the most common and critical codes. For the complete official list of fault codes and full parameter context, download the Rockwell guide here:

PowerFlex 525 Adjustable Frequency AC Drive On-Drive Guide (PDF)