7
Series L: Models LB, LBP, LD, and LDP
®
Troubleshooting
WARNING: Before taking any corrective action, make certain unit is not capable of operation during repairs.
PROBLEM
CAUSE
CORRECTIVE ACTION
Reduced Airflow
System resistance too high
Check system for proper operation of backdraft or
control dampers; remove obstructions in ductwork, etc.
Unit running backwards
See Pre-Starting Checks.
Fan speed too low
Increase fan speed.
Excessive dirt buildup on
wheel
Clean wheel.
Improper wheel alignment
Center wheel on inlets.
Excessive Noise
or Vibration
Bad Bearings
Replace.
Belts too tight or too loose
Refer to Figure 4 and adjust tension.
Wheel improperly aligned and
rubbing
Center wheel on inlets. See Figure 1.
Loose drive or motor pulleys
Align and tighten. See Pre-Start-up Checks.
Foreign objects in wheel or
housing
Remove objects, check for damage or unbalance.
Unbalance of wheel caused
by excessive dirt and grease
buildup
Remove buildup.
Job Information
Job Name:___________________________________ Service Organization: _________________________________
Address: ____________________________________ Address: _____________________________________________
City: ________________________________________ City: _________________________________________________
State:
_______________ Zip:
__________________ State:
_______________ Zip:
__________________________
Phone: ______________________________________ Phone: ______________________________________________
Contact Person: ______________________________ Work Done By: _______________________________________
Nameplate Information
Field Start-Up Documentation
Model: ______________________________________
Volts: ________ Hertz:
________ Phase:
______ Actual
Voltage:
_______ Hertz:
______ Phase:
_________
Amps: _______________
Mark: ________________ Actual Amperage: ____________________________________
Supply hp: ___________ Exhaust hp: __________ Blower Rotation: _____________________________________
Serial Number: _______________________________ Air Volume: Design cfm: _____________________________
Model Voltage: _______________________________
Actual cfm: ______________________________
Motor Amperage: ____________________________ Level of fan (L or H): __________________________________
Fan RPM: ___________________________________ Fan RPM Range (min.) ___________ (max.) _____________
Maintenance Documentation
