I²t overload

What does OC6 mean?

This fault signifies an I²t overload condition, where the motor or drive has been operating with high current for an extended duration, causing excessive heat. The default behavior for this fault is to be switchable off, suggesting it might be configurable to a warning or message level, but its presence still indicates potential thermal stress on the components if not addressed.

• Continuous operation of the motor and drive at a current exceeding the drive's internal I²t thermal model limit (e.g., P1-54).
• Inadequate cooling of the drive itself (e.g., blocked heatsink fins, failed cooling fan) leading to its internal I²t reaching critical levels.
• Motor and drive are undersized for the application's continuous load requirements, resulting in sustained high current.
• Recurring transient overloads that accumulate heat faster than it can dissipate, triggering the I²t model.
• Incorrect configuration of the drive's I²t trip level (e.g., P1-54 Motor thermal time constant) for the specific application.

Click steps to track your progress.

1. 1

   Measure the actual RMS current drawn by the motor and verify it is below the drive's continuous output current rating (P0-02) and motor nameplate.

2. 2

   Check the drive's internal cooling fans for proper operation and ensure the heatsink fins are free of dust and debris; measure heatsink temperature (P6-01).

3. 3

   Review the drive's I²t thermal model parameters (e.g., P1-54, P0-03) and ensure they are correctly set for the connected motor and application.

4. 4

   Evaluate the mechanical load on the motor; perform torque measurements on the driven equipment if possible to confirm load is within limits.

5. 5

   Consider increasing the drive's nominal output current (P0-02) or motor rated current (P0-03) within limits, if justified by the application and motor.

6. 6

   Log current and load profiles over an extended period to identify peak demands or continuous high-current operation.