Current Detection Fault

What does Er - 12 mean?

This fault occurs during Auto-Tuning when the motor current exceeds its rated value or an open phase is detected on the U/T1, V/T2, or W/T3 output terminals. It suggests an issue with the motor connection, wiring, or an attempt to tune a loaded motor, which can skew current measurements.

• Open phase on the motor output wiring (U/T1, V/T2, W/T3) due to a loose connection, broken wire, or faulty contactor between the drive and motor.
• Motor winding short circuit or insulation breakdown within the motor, causing excessive current draw.
• Motor cable short circuit or ground fault between the drive output terminals and the motor terminals.
• Incorrect motor data entered into drive parameters (e.g., E1-01, E1-02) causing the auto-tuning process to attempt to drive the motor with inappropriate current limits.
• Internal failure of the drive's current sensors (e.g., Hall effect sensors) or their associated circuitry.

Click steps to track your progress.

1. 1

   Perform a thorough visual inspection of the motor output wiring from the drive's U/T1, V/T2, W/T3 terminals to the motor junction box for any loose or disconnected cables.

2. 2

   Using an ohmmeter, measure the resistance between each motor output phase (U to V, V to W, W to U) at the motor's terminal box, ensuring all three readings are balanced and non-infinite.

3. 3

   Perform an insulation resistance test (megger) on the motor windings to ground and between phases, checking for values above 1 megaohm (MΩ).

4. 4

   Verify that motor nameplate data (rated current, rated voltage, rated frequency) is correctly programmed into drive parameters like E1-01 (Motor Rated Current) and E1-02 (Motor Rated Voltage).

5. 5

   If a motor contactor is used between the drive and motor, manually check its contacts for proper engagement and verify coil operation.