Troubleshooting - CaptiveAire D76 Installation, Operation And Maintenance Manual

Troubleshooting

The following table lists causes and corrective actions for possible problems with the fan units. Review this
list prior to consulting manufacturer. The following table lists causes and corrective actions for possible
problems with the fan units. Review this list before consulting manufacturer.
Airflow Troubleshooting Chart
Problem
Fan Inoperative
Motor Overload
Insufficient Airflow
Excessive Airflow
Excessive Vibration and
Noise
Potential Cause
Blown fuse/Open circuit breaker
Disconnect switch in "OFF" position
Incorrect wiring to motor
Broken fan belt
Motor starter overloaded
Incorrect fan rotation
Fan speed is too high
Incorrect wiring to motor
Overload in starter set too low
Motor HP too low
Duct static pressure lower than design
Incorrect fan rotation
Poor outlet conditions
Intake damper not fully open
Duct static pressure higher than design
Blower speed too low
Supply grills or registers closed
Dirty/clogged filters
Belt slippage
Blower speed too high
Filters not installed
Duct static pressure lower than design
Damaged/Unbalanced
Misaligned pulleys
Fan is operating in unstable region of fan
curve
Bearings need lubrication/Damaged bearing Lubricate bearings, replace if damaged.
Fan speed is too high
Dirty/oily belt(s)
Belt(s) too loose
Worn belt(s)
Check amperage.
Check fuse, replace if needed.
Check circuit breaker.
Place switch to the "ON" position.
Inspect motor wiring. Verify connections with
wiring diagram located on fan motor.
Replace belt.
Check amperage.
Reset starter.
Verify that the fan is rotating in the direction
shown on rotation label.
Reduce fan RPM.
Inspect motor wiring. Verify connections with
wiring diagram located on fan motor.
Set overload to motor's FLA value.
Determine if HP is sufficient for job.
Reduce fan RPM.
Verify that the fan is rotating in the direction
shown on rotation label.
Check duct and connections. There should be
a straight duct connection to the outlet.
Inspect damper linkage. If the linkage is
damaged, replace damper motor.
Check ductwork. Adjust/resize to eliminate or
reduce duct losses.
Increase fan RPM. Do not overload motor.
Open/Adjust.
Clean filters. Replace filters if they cannot be
cleaned or are damaged.
Adjust belt tension.
Reduce fan RPM.
Install filters.
Reduce fan RPM.
Replace wheel.
Align pulleys.
Refer to performance curve for fan.
Reduce fan RPM.
Clean belt(s).
Adjust, replace if necessary.
Replace belt(s).
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Corrective Action