Schneider Altivar VFD Diagnostics
Schneider Altivar drives are used in material handling and pumping applications. This guide covers key error codes and remedies.
1. OCF - Overcurrent Fault
The drive has detected excessive output current. Causes: Short circuit in the motor, cable issue, or damaged power components. Action: Perform a static diode test on the drive's output stage. Replace shorted IGBTs and driver components.
2. OSF - Overvoltage Fault
The DC bus voltage has exceeded the safety threshold. Causes: High input grid voltage or regenerative feedback. Action: Adjust deceleration ramp times or inspect the braking chopper and resistors.
3. USF - Undervoltage Fault
The DC bus voltage is too low. Causes: Input voltage fluctuations, phase loss, or pre-charge circuit fault. Action: Measure the input voltage, check the pre-charge contacts, and replace degraded DC link capacitors.