Alarm 16 on a Danfoss VFD (Variable Frequency Drive) indicates a short circuit detected between the drive and the motor. This is a serious issue that can damage the drive and the motor if not addressed promptly.

Here's a breakdown of Alarm 16 and steps you can take to troubleshoot the problem:

Possible Causes:

• Motor Winding Short Circuit: A short circuit within the motor windings themselves can cause this alarm.
• Cable Damage: Damage to the motor cable, such as cuts, abrasions, or internal shorts, can create a short circuit path.
• Internal Drive Fault (less likely): In rare cases, an internal issue within the VFD itself might be responsible for the false short circuit detection.

Troubleshooting Steps:

1. Safety First: Absolutely ensure the system is completely powered down and locked out before attempting any troubleshooting procedures. High voltage is present and can cause serious injury or death.
2. Isolate the Drive and Motor: Disconnect the motor cable from the VFD output terminals to isolate the two components.
3. Visually Inspect Motor Cable: Carefully examine the motor cable for any signs of physical damage or wear, especially near the motor terminals and connector points.

4. Check Motor Terminals: On the disconnected motor, visually inspect the motor terminals for any signs of burning or overheating, which could indicate a short circuit within the motor itself.