oL2 Overload (Drive) fault in delta drive

oL2 Overload (Drive) fault in delta drive troubleshooting

Description

oL2 protects the VFD itself. It indicates the drive is outputting more current than its internal components are rated for (e.g., 150% for 60 seconds). Unlike oL1 (which protects the motor), oL2 implies the drive is undersized for the task.

Causes

1. Undersized Drive: The motor is larger than the drive, or the load requires torque that exceeds the drive's peak capacity.
2. High Friction: A mechanical bind is causing high current that doesn't quite trip instantaneous OC, but sustains high enough to heat up the drive logic.
3. V/F Mismatch: Excessive Torque Boost settings can cause high current saturation at low speeds.

Solution

Upgrade or adjust:
1. Upsize Drive: If the current draw is consistently near the drive’s maximum limit, replace the VFD with the next power size up.
2. Reduce Load: lessen the mechanical burden.
3. Lower Torque Boost: Reduce the Torque Compensation voltage. Too much boost saturates the motor core, drawing high current without producing extra torque.
4. Duty Cycle: Review the application. Is it Heavy Duty (constant torque) or Normal Duty (fan/pump)? Ensure the drive is rated for the specific duty cycle.