Speed limit

What does 49 mean?

The motor speed is not within the specified range set in parameters 4-11 (Motor Speed Low Limit) and 4-13 (Motor Speed High Limit), generating a warning. If the speed drops below the limit set in 1-86 (Trip Speed Low) (except during start/stop), the frequency converter will trip. This indicates an operational deviation that could affect process control or product quality.

• Motor operating above P4-13 (Motor Speed High Limit) due to an over-commanded speed reference or incorrect scaling.
• Motor operating below P4-11 (Motor Speed Low Limit) or P1-86 (Min Speed Warning Limit) due to excessive mechanical load or friction.
• Incorrect scaling factor applied to the speed feedback signal (e.g., encoder resolution in P1-20 set incorrectly).
• Loss of motor speed feedback signal (e.g., encoder cable fault) causing the drive to lose accurate speed information.
• Sudden load changes or mechanical braking causing the motor speed to momentarily exceed or drop below defined limits.

Click steps to track your progress.

1. 1

   Verify parameters P4-11 (Motor Speed Low Limit), P4-13 (Motor Speed High Limit), and P1-86 (Min Speed Warning Limit) are set appropriately for the application.

2. 2

   Monitor the actual motor speed using the drive's display (e.g., P16-00 Measured Motor Speed) and compare it against the commanded speed reference.

3. 3

   Check the settings for the speed feedback source (e.g., P1-20 Encoder Resolution, P1-21 Motor Poles) for accuracy if an encoder is used.

4. 4

   Inspect the mechanical system for excessive friction, bearing wear, or misaligned components that could restrict or over-speed the motor.

5. 5

   Adjust acceleration and deceleration ramp times (e.g., P3-41, P3-42) to prevent transient speed excursions during changes in reference.

6. 6

   Verify the scaling of the speed reference input (e.g., P6-10 Analog Input 1 High Reference) matches the expected motor speed range.