Power Recovery Restart Prevention (USP) Error

What does E13. mean?

The USP error occurs when the inverter's power recovery restart prevention function is activated. This specific fault triggers if the power supply is turned on while the RUN command is already active, preventing unintended motor restarts after a power interruption. It's a safety feature designed to ensure controlled startup.

• Inverter input power is cycled (lost and restored) while the RUN command signal (e.g., via digital input S1 or communication) is still active.
• Control circuit providing the RUN command is not properly sequenced to remove the command BEFORE main power is reapplied.
• Persistent RUN command from a communication bus (e.g., Modbus, EtherNet/IP) after a power outage.
• Parameter (e.g., P6-06 Power Recovery Restart) is enabled and detecting an unsafe restart condition.
• Intermittent or unstable main input power causing repeated power loss and restoration events while RUN is active.

Click steps to track your progress.

1. 1

   Ensure the RUN command signal (e.g., on terminal S1 or S2) is removed (e.g., 0VDC) BEFORE applying main input power to the inverter.

2. 2

   Review the control logic (PLC/DCS program) responsible for the RUN command to ensure it deactivates the command during a power loss event.

3. 3

   If using a communication network, verify that the RUN command bit is reset to '0' during power-up sequences of the control system.

4. 4

   Temporarily disable the Power Recovery Restart Prevention function (e.g., set P6-06 to '0') for diagnostic purposes, then re-enable after troubleshooting.

5. 5

   Monitor the incoming AC line voltage (R, S, T) for stability and to identify any intermittent power losses that trigger the fault.