Overvoltage

What does OSF mean?

The input line voltage supplied to the soft starter has exceeded the permissible limits. This condition can potentially damage the soft starter's power components and other connected equipment.

• Input line voltage from the mains supply consistently exceeds the soft starter's maximum permissible input voltage (e.g., >528VAC for a 480V unit).
• Regenerative energy from a high inertia load rapidly decelerating without adequate braking (can occur if fast stop is initiated).
• Unstable or poorly regulated grid supply with frequent voltage spikes or surges.
• Incorrect soft starter model selected for the available line voltage (e.g., 400V unit on a 480V system).
• Faulty voltage sensing circuit within the soft starter providing inaccurate readings.

Click steps to track your progress.

1. 1

   1. Measure the incoming line voltage (L1-L2, L2-L3, L3-L1) at the soft starter's input terminals using a true RMS voltmeter; monitor for spikes over time.

2. 2

   2. Verify that the supply voltage consistently remains within the soft starter's specified operating voltage range (e.g., 380-480VAC).

3. 3

   3. Check power quality upstream of the soft starter for transients using a power quality analyzer if persistent voltage spikes are suspected.

4. 4

   4. Review soft starter parameters for any voltage monitoring thresholds (e.g., P6-01 (Overvoltage Trip Level)) and ensure they are appropriately set for the application.

5. 5

   5. Confirm that the installed soft starter is rated for the nominal input line voltage (e.g., 400V, 480V, 600V).