FloAire DMUA - Manual (Page 22)

22
Troubleshooting
The following table lists causes and corrective actions for possible problems with the fan units. Review
this list prior to consulting manufacturer.
Troubleshooting Chart
Problem Potential Cause Corrective Action
Fan Inoperative Blown fuse or open circuit breaker Replace fuse or reset circuit
breaker and check amps
Disconnect switch in “Off” position Turn to “On” position
Motor wired incorrectly Check motor wiring to wiring
diagram located on fan motor
Broken fan belt Replace belt
Motor starter overloaded Reset starter and check amps
Motor Overload Fan rotating in the wrong direction Be sure fan is rotating in the
direction shown on rotation label
Fan speed is too high Reduce fan RPM
Motor wired incorrectly Check motor wiring to wiring
diagram located on fan motor
Overload in starter set too low Set overload to motor FLA value
Motor HP too low Determine if HP is sufficient for
job
Duct static pressure lower than
design Reduce fan RPM
Insufficient Airflow Fan rotating in the wrong direction Be sure fan is rotating in the
direction shown on rotation label
Poor inlet/outlet conditions There should be a straight clear
duct at the inlet/outlet
Damper not fully open Inspect damper linkage and
replace damper motor if needed
Duct static pressure higher than
design Improve ductwork to eliminate or
reduce duct losses
Blower speed too low Increase fan RPM. Do not
overload motor
Belt slippage Adjust belt tension
Excessive Airflow Blower speed to high Reduce fan RPM
Duct static pressure lower than
design Reduce fan RPM
Excessive Vibration and Noise Misaligned pulleys Align pulleys
Damaged or unbalanced wheel Replace wheel
Fan is operating in the unstable
region of the fan curve Refer to performance curve for
fan
Bearings need lubrication or
replacement Lubricate or replace
Fan speed is too high Reduce fan RPM
Belts too loose, worn or oily Inspect and replace if needed