Cause: Overvoltage comes when drive detected that the DC link voltage exceeded the allowed maximum value, which typically happens during rapid deceleration or other conditions where the motor is generating excessive voltage back into the drive.

danfoss w7 alarm indicates a DC link overvoltage. This means the voltage in the intermediate DC circuit of the drive has exceeded its permissible limit.

Troubleshooting Steps for a Danfoss W7 Alarm:

Follow these steps to correct danfoss w7 alarm:

• Check the Mains Voltage: Measure the incoming AC line voltage and ensure it is within the acceptable range specified.
• Increase Deceleration Ramp Time: If the deceleration time is set too short, try increasing it to allow the motor to slow down more gradually.
• Verify Braking Resistor (if used): Ensure a braking resistor is installed if the application involves frequent or rapid deceleration or overhauling loads.
• Check Motor and Load: Ensure the motor is appropriately sized for the application and that the load is not excessively high, which could exacerbate regenerative effects during deceleration.

How to Reset a W7 Alarm:

Typically, a W7 warning will clear automatically once the DC link voltage drops back within the acceptable range. If it trips into a fault state, you might need to:

• Press the [Reset] button on the VFD keypad.
• Cycle the power to the VFD (turn it off and then back on).
• In some cases, a parameter setting might need to be adjusted to enable automatic reset after a warning condition.