Troubleshooting Panasonic Servo Drive Error 16.0 | Overcurrent Protection

Learn how to identify and fix the SCF3 (Ground Short Circuit) fault in Schneider Electric VFDs like ATV320, ATV630, and ATV930. Follow our step-by-step troubleshooting guide.

A complete guide to fixing Error 16.0 on Panasonic Minas A5 and A6 servo drives. Learn how to diagnose overcurrent issues, check IGBTs, and inspect motor wiring.

 

Panasonic Servo Drive: Error 16.0 Guide

In Panasonic Minas A4, A5, and A6 series drives, Error 16.0 is one of the most serious alarms. It indicates Overcurrent Protection, meaning the current flowing through the drive's power transistors (IGBTs) has exceeded the allowable limit.

Error Code: Err 16.0
Message: Overcurrent Protection / Power Module Error
Main Cause: Short circuit, motor insulation failure, or drive hardware defect.

Common Root Causes

• Short Circuit: A short between motor power lines (U, V, W) or a short to the ground.
• Motor Burnout: Internal winding insulation failure within the servo motor.
• IGBT Failure: The internal power module of the Panasonic drive is damaged.
• Dynamic Brake Fault: Excessive use of the dynamic brake or a faulty external regenerative resistor.
• Parameter Mismatch: Extremely high gain settings causing current spikes.

CAUTION: High voltage remains in the drive's capacitors even after power is disconnected. Wait at least 15 minutes before touching terminals.

Troubleshooting Steps

1. The Isolation Test (Drive vs. Motor)

Turn off the power and disconnect the motor power cable (U, V, W) from the drive terminals. Turn the power back on.
• If Err 16.0 occurs immediately: The drive's internal power module is likely shorted. The drive must be repaired or replaced.
• If the error does NOT occur: The issue is in the cable or the motor.

2. Check Motor Wiring

Inspect the motor power cable for any cuts, abrasions, or pinches. Use a multimeter to check for continuity between phases (U-V, V-W, W-U) and ensure there is no continuity between any phase and the ground/shield.

3. Measure Motor Resistance

Using an Ohmmeter, measure the resistance between the phases of the motor. The values should be very low but perfectly balanced. If one phase shows significantly different resistance, the motor windings are damaged.

4. Check Regenerative Resistor

If you are using an external regenerative resistor, check the wiring and the resistance value. If the resistor is shorted, it can trigger overcurrent errors during deceleration.

5. Review Gain Settings

If Error 16.0 occurs only during high-speed moves or rapid acceleration, check your Inertia Ratio and Gain settings. Use the PANATERM software to auto-tune the drive and ensure the motor isn't oscillating violently.

Hardware Verification Table

Symptom	Likely Component
Error appears with motor disconnected	Servo Drive (Internal)
Error appears only when motor turns	Motor Insulation or Cable
Error appears during hard braking	Regenerative Resistor