High Slip Braking Overload

What does oL7 mean?

This fault is triggered when the load inertia is excessively large, an external force rotates the motor, or deceleration is impeded. It can also occur if the n3-04 [HSB Overload Time] parameter is set too low. The drive detects this when the output frequency remains constant beyond the duration specified by n3-04. Ignoring this can lead to excessive heat and damage to the drive or motor.

• Excessively large load inertia exceeding the drive's braking capability, leading to high slip during deceleration.
• External mechanical force (e.g., gravity, another machine) driving the motor shaft during deceleration.
• Deceleration time (e.g., C1-02 [Deceleration Time 1]) set too short for the inertia, requiring high braking torque.
• Parameter n3-04 (HSB Overload Time) is set too low, tripping the fault prematurely.
• Failure or improper operation of external braking resistor (if used) leading to insufficient energy dissipation.

Click steps to track your progress.

1. 1

   1. Increase the deceleration time (e.g., C1-02) in small increments to reduce the required braking torque.

2. 2

   2. Increase parameter n3-04 (HSB Overload Time) to allow for longer periods of high slip braking.

3. 3

   3. Verify the external braking resistor (if installed) has the correct resistance and power rating, and that its terminals are connected correctly (e.g., B1, B2).

4. 4

   4. Measure the actual braking resistor resistance (using a multimeter) and compare it to the specified value.

5. 5

   5. Inspect the mechanical system for any external forces or back-driving conditions during deceleration.

6. 6

   6. Configure regenerative braking settings (e.g., n3-01 [HSB Level]) to optimize energy dissipation for the application.