Overheat Pre-Alarm

What does OH mean?

The Overheat (OH) Pre-Alarm indicates that the drive's cooling fin temperature has exceeded the threshold set in parameter L8-02. Depending on the setting of L8-03, this condition can either trigger a fault detection (with the fault contact activating) or function as an alarm only. Ignoring this pre-alarm can lead to a more severe overheat fault (like OH1) and potential damage to the drive if the temperature continues to rise.

• Ambient temperature around the drive within the control cabinet exceeds its specified maximum operating limit.
• Blocked or restricted airflow to the drive's cooling fins due to dust accumulation or enclosure design.
• Failure or reduced efficiency of the drive's internal cooling fan (if not separately monitored by OH1).
• Accumulation of dust and debris on the heat sink fins, reducing cooling performance.
• Overloading of the drive, causing internal components to generate more heat than usual.

Click steps to track your progress.

1. 1

   1. Measure the ambient temperature within the control cabinet using a thermometer and compare it to the drive's specifications.

2. 2

   2. Clear any obstructions blocking the drive's cooling air intake or exhaust vents.

3. 3

   3. Clean dust and debris from the drive's heat sink fins using compressed air (ensure power is off and wear appropriate PPE).

4. 4

   4. Verify the drive cooling fan is operating correctly and producing adequate airflow.

5. 5

   5. Review L8-02 (Overheat Pre-Alarm Level) setting to ensure it is appropriate for the application's operating conditions.