No motor

What does WARNING/ALARM 3 mean?

No motor is detected as connected to the output of the frequency converter. This condition prevents the drive from operating and indicates a potential wiring issue or a missing motor connection.

• Open circuit in one or more motor phases (U, V, W) between the drive output terminals and the motor terminal box.
• Loose or disconnected motor power cables inside the motor terminal box or at the drive's output terminals (e.g., T1, T2, T3).
• Internal damage to the motor winding (e.g., a completely open phase winding) preventing current flow.
• External motor output contactor (if present) failed in an open position or not properly engaging during a run command.

Click steps to track your progress.

1. 1

   With power off, measure the resistance between the drive's output terminals U, V, W (or L1, L2, L3 for single-phase) to verify continuity and balanced phase resistance (typical 0.1-100 Ohms).

2. 2

   Verify all motor power cable connections are secure and properly terminated at both the drive's output terminals (e.g., T1, T2, T3) and the motor terminal box.

3. 3

   Disconnect the motor power cables from the drive and measure the winding resistance directly at the motor terminals (U-V, V-W, W-U); ensure readings are balanced.

4. 4

   If an external motor output contactor is installed, check its coil for proper energization (e.g., 24VDC) and confirm its main power contacts close when a run command is active.

5. 5

   Ensure that the drive's motor data parameters (e.g., P1-20 'Nominal Voltage', P1-22 'Nominal Current', P1-23 'Nominal Speed') are accurately entered for the connected motor.