Direct Gas Make-Up Air
49
Troubleshooting
Supply Fan
Problem: Motor overamps.
Motor voltage correct?
Yes
No
Provide proper power supply
. Reference Supply Fan, Start-Up.
Fan rotation correct?
Yes
No
Reverse fan rotation
. Reference Supply Fan, Start-Up.
Air volume too high?
No
Yes
Adjust drives or increase external static pressure as needed
.
Reference Supply Fan, Start-Up.
Actual static pressure lower than
design?
No
Yes
Adjust drives to reduce fan RPM
. Reference Supply Fan, Start-Up.
All three phases supplied to motor?
Yes
No
Supply motor fuse (FU1) blown
. Test and replace blown fuse(s).
Motor horsepower too low?
No
Yes
Resize motor.
Shorted windings in motor?
Yes
Replace motor.
Everything is working properly, consult factory.
Problem:
Insufficient airflow.
Damper(s) not fully opened?
No
Yes
Adjust damper linkage(s), or replace faulty actuator(s).
Damper
actuators may take a few minutes to open.
Fan rotation correct?
Yes
No
Reverse fan rotation.
Reference Supply Fan, Start-Up.
Filters dirty or clogged?
No
Yes
Clean or replace filters.
Reference Maintenance, General, Filters.
Belt slipping or broken?
No
Yes
Replace or tighten belt
. Reference Maintenance, General, V-Belt
Drives.
Fan speed too low?
No
Yes
Adjust drives as needed
. Reference Supply Fan, Start-Up section.
System static losses too high?
No
Yes
Reduce losses by improving ductwork
.
Leaks in ductwork?
Yes
Repair leaks.
Everything is working properly, consult factory.
Problem: Excessive noise or vibration.
Belts worn or loose?
No
Yes
Replace worn belts or tighten loose belts.
Reference
Maintenance, General, V-Belt.
Sheaves aligned?
Yes
No
Align sheaves.
Reference Maintenance, General, V-Belt Drives.
Wheel(s) unbalanced?
No
Yes
Clean and/or balance wheel(s).
Bearings worn or need lubrication?
No
Yes
Replace worn bearings or lubricate bearings as needed.
Reference Maintenance, General, Bearings.
Wheel(s) rubbing on inlet?
No
Yes
Adjust wheel(s) or inlet.
Fan rotation correct?
Yes
No
Reverse fan rotation.
Reference Supply Fan, Start-Up.
Everything is working properly, consult factory.