Motor speed feedback

What does 7301 mean?

No motor speed feedback signal is being received by the drive. This fault means the drive cannot accurately monitor motor speed, which is critical for closed-loop control and protection. The drive will likely trip or fail to start reliably, impacting performance and safety.

• Encoder or resolver feedback cable damage (e.g., open circuit in signal lines, short to ground, poor shielding).
• Encoder/resolver malfunction (e.g., internal failure, loss of 5VDC or 15VDC power supply to the device).
• Incorrect wiring of feedback signals (e.g., A/B/Z signals swapped or connected to wrong terminals X20, X21).
• Loose or corroded terminals at the encoder, motor junction box, or drive's feedback connector (e.g., X20, X21).
• Excessive electromagnetic interference (EMI) on feedback cables without proper shielding and grounding.

Click steps to track your progress.

1. 1

   Verify 5VDC or 15VDC power supply to the encoder at the encoder connector (e.g., pins 1 and 2).

2. 2

   Check continuity of each signal wire (A, /A, B, /B, Z, /Z) from the encoder to the drive's feedback terminals (e.g., X20, X21).

3. 3

   Visually inspect the encoder or resolver for mechanical damage, contamination, or loose mounting on the motor shaft.

4. 4

   Confirm encoder parameters (e.g., P21-01 Encoder type, P21-02 Pulses per revolution) match the installed feedback device.

5. 5

   Ensure proper shielding of the feedback cable is connected to ground at the drive's shield clamp and at the motor frame.