Alarm 12 on a Danfoss VFD indicates a torque limit issue. This means the motor connected to the VFD is trying to produce more torque (turning force) than the drive allows.

Here's a breakdown of what the alarm signifies and how to troubleshoot it:

Cause:

• Motor Overload: The motor might be working harder than it's designed to, causing it to demand more torque than the VFD limit. This could be due to mechanical issues like jams or excessive friction.
• Incorrect Settings: The torque limit parameters (typically 4-16 or 4-17) in the VFD might be set too low for the current application.
• Ramp-up Time: If the motor tries to reach high torque too quickly during startup (rapid acceleration), it can trigger the alarm.

Troubleshooting Steps:

1. Reduce Load: If possible, try to reduce the mechanical load on the motor. This will lessen the torque demand.
2. Verify Motor Data: Ensure the motor's specifications (horsepower, torque rating) are correctly entered in the VFD parameters.
3. Adjust Torque Limit: If necessary, increase the torque limit value in VFD parameters (refer to your specific Danfoss VFD manual for parameter locations). Be cautious not to set it excessively high, as it could damage the motor if overload persists.
4. Check Ramp Times: Consider extending the acceleration and deceleration ramp times in the VFD settings. This allows the motor to reach the desired speed more gradually, reducing the initial torque demand.