USP (Unattended Start Protection) Error

What does E13 mean?

This fault occurs when the Unattended Start Protection (USP) function is enabled and a Run command is present simultaneously with the application of power. It prevents the motor from unexpectedly starting upon power-up, requiring deliberate action to clear the fault and resume operation, enhancing safety.

• A 'Run' command (digital input or communication command) is active (e.g., terminal FWD/REV high) when the inverter is powered on.
• USP function (Parameter P6-01) is enabled, requiring the run command to be OFF at power-up.
• Sticky relay or faulty switch providing a persistent run command signal, even when disengaged.
• Communication error or noise on the serial link (e.g., Modbus) causing a 'Run' command to be inadvertently sent.
• Incorrect configuration of input terminals (e.g., P4-01) or communication settings, causing a default 'Run' state.

Click steps to track your progress.

1. 1

   Ensure that all 'Run' commands (e.g., FWD, REV digital inputs) are OFF (low signal) before applying main power to the inverter.

2. 2

   Check the state of the digital input terminals (e.g., FWD, REV) using a multimeter to confirm they are at 0V (or logic low) when power is applied.

3. 3

   If using serial communication, verify that no 'Run' command is sent by the master device until after the inverter has fully initialized.

4. 4

   Disable the Unattended Start Protection function (Parameter P6-01 set to 0) if the application design permits and risks are acceptable.

5. 5

   Trace the control wiring for 'Run' commands to ensure no short circuits or faulty switches are maintaining an active signal.