OverVoltage

What does F5 mean?

This fault occurs when the incoming AC line experiences high voltage or transient conditions, or when the motor regenerates energy back into the drive (e.g., during rapid deceleration). This can cause the DC bus voltage to exceed safe limits. This is an Auto-Reset/Run type fault configurable with parameters A092 and A093.

• High input line voltage from the utility or plant distribution system exceeding the drive's specified maximum operating voltage.
• Rapid deceleration of a high-inertia load, causing the motor to act as a generator and feed energy back to the drive's DC bus.
• Malfunctioning or incorrectly sized dynamic braking resistor (if installed), unable to dissipate regenerated energy.
• Failure of the drive's internal DC bus voltage regulation circuitry, leading to an uncontrolled voltage rise.
• Voltage transients (spikes) on the incoming AC line caused by switching inductive loads or power factor correction capacitors.

Click steps to track your progress.

1. 1

   Measure the incoming AC line voltage (L1-L2, L2-L3, L3-L1 for 3-phase, L1-N for 1-phase) at the drive's input terminals and compare to drive specifications.

2. 2

   Monitor the drive's DC bus voltage (via display) during operation, particularly during deceleration ramps, and compare to the Overvoltage trip threshold.

3. 3

   If regenerating load is present, inspect the dynamic braking resistor for proper connection, resistance value (using an ohmmeter), and signs of overheating.

4. 4

   Increase the deceleration ramp time (e.g., parameter P004 [Decel Rate 1]) to reduce the rate of regenerated energy back to the drive.

5. 5

   Check for external sources of voltage transients (e.g., capacitor bank switching, large motor starts) on the power line feeding the drive.