Speed error

What does 61 mean?

The motor's actual speed deviates significantly from its commanded speed reference. This can be caused by a faulty encoder connection (if an encoder is used), or for Permanent Magnet Synchronous (PMS) motors, exceeding the pull-out torque. An uncorrected speed error leads to inaccurate motor control, poor process performance, and potential instability.

• Encoder feedback cable damage (e.g., open circuit, short circuit) or loose connection at drive or encoder.
• Encoder sensor failure or contamination causing inconsistent pulse generation.
• Incorrect encoder parameters (e.g., P1-20, P1-21 for pulse count) in the drive setup.
• Motor shaft coupling slippage or mechanical load issue preventing motor from reaching commanded speed.
• For PMS motors, incorrect motor parameters (e.g., P1-10, P1-11 for motor poles) or incorrect phase detection.
• Excessive motor load exceeding drive's torque capabilities, leading to slip or inability to accelerate.

Click steps to track your progress.

1. 1

   Verify all encoder cable connections (e.g., terminals 88, 89, 90 on drive) for proper seating and continuity using a multimeter.

2. 2

   Measure encoder pulse output (e.g., channels A, B, Z) with an oscilloscope while rotating the motor slowly, checking for signal integrity.

3. 3

   Confirm drive parameters P1-20 (Encoder resolution) and P1-21 (Encoder type) match the installed encoder specifications.

4. 4

   Inspect motor shaft coupling for tightness and verify no slippage under load.

5. 5

   For PMS motors, re-run auto-tuning (e.g., Parameter P1-30 set to '2' or '3') to ensure correct motor data is learned.

6. 6

   Monitor drive's actual speed feedback (e.g., via LCP or software) and compare to commanded speed reference to quantify deviation.