American Power Conversion DX Manual De Usuario

Airflow too low

• Blower setting too low
• Dirty or blocked air filters
• External static pressure too high

• Raised floor height too low

• Return airflow restriction

• Supply airflow restriction

• Increase blower setting.
• Check filters and replace as needed.
• Increase the blower speed to compensate.
• Verify floor height is not less than 18 in. Check 

for under floor obstructions.

• Check return duct sizing and and return grille 

openings.

• Check supply duct sizing and supply grille 

openings.

Blower motor fails 
to start

• System is off
• System time delay is active
• Remote shutdown or input contact 

is active

• Airblock interlock alarm

• VFD alarm
• Frequency drive has failed
• Blown fuse or fuses

• No run signal to VFD
• Blower failure

• Turn System on.
• Allow ample time to expire.
• Check input contact configuration settings.

• Check airblock panels and secure as needed. 

Check interlock switches and wiring 
connections.

• Check alarm for specific fault code.
• Replace the frequency drive.
• Check for shorted wiring, failed motor, failed 

VFD, and proper voltage. Replace fuses with 
specified type.

• Check VFD control wiring and connections.
• Replace blower assembly.