Supply Fan VFD Failure alarm

What does Supply Fan VFD Failure mean?

This alarm indicates a problem with the variable frequency drive (VFD) that controls the supply fan. It may occur if there is a fault within the VFD itself or if the electrical connection to it is interrupted.

• Loss of 24 VAC power at the VFD fault input on the SEC board
• Fault within the VFD
• Improper air balancing of the unit
• Blower motor exceeding amperage limits
• Incorrect VFD amperage or voltage settings for the blower motor

Click steps to track your progress.

1. 1

   Check for 24 VAC at the VFD fault input on the SEC board. If absent, unplug the VFD and SEC board, then reset the unit. If the alarm persists, replace the SEC board.

2. 2

   If 24 VAC is present, check the VFD for specific fault codes and follow VFD manufacturer's instructions.

3. 3

   Ensure the unit is properly air balanced and the blower motor is not exceeding its rated amperage.

4. 4

   Verify that the VFD amperage and voltage settings match the blower motor specifications.