Larkin Industries, Inc.
114 David Green Rd., Birmingham, AL 35244
Phone: 1.800.322.4036 Fax: 1.205.987.0583
Email: [email protected]
474589 • XRAE and XRAS, Rev. 3, March 2018
Copyright 2018 © Larkin Industries, Inc.
2
Troubleshooting
Problem
Cause
Corrective Action
Ventilator
Inoperative
Blown fuse or breaker
Replace or repair motor
Defective motor
Replace or repair
Incorrectly wired
Shut power OFF and check wiring
for proper connections
Insufficient
Airflow
Blocked duct or clogged filters
Clean or replace
Speed too slow
Check for correct drives
Damper closed
Inspect/repair damper
Incorrect propeller rotation
Check motor wiring
Loose fitting duct sections
Check for secure connection
where duct permitting air loss
sections are joined (suggest duct
tape at seams for sealed closure)
Excessive
Noise or
Vibration
Loose propeller
Tighten set screws
Accumulation of material on propeller Clean
Ventilator base not securely anchored Secure properly
Motor hood loose and rattling
Tighten acorn nuts securing
motor hood
Fan propeller out of balance
Replace propeller
Motor
Overloads or
Overheats
Propeller RPM too high
Check drives
Shorted motor winding
Replace motor
Incorrect propeller rotation
Check motor wiring
Over/Under line voltage
Contact power Company
Maintenance
Disconnect and lockout power source
before servicing.
Uneven cleaning of the propeller will
produce an out-of-balance condition that
will cause vibration in the ventilator.
1. Keep inlets and approaches to ventilator
clean and free from obstruction.
Depending on the usage and severity
of the contaminated air, a regularly
scheduled inspection for cleaning the
fan propeller, ventilator, and surrounding
areas should be established.
2. Check for unusual noises when fan is
running.
3. Periodically inspect and tighten
setscrews.
4. Follow motor manufacturer’s instructions
for motor lubrication.
Parts List
Shroud
Propeller
Motor Cover
Isolator Kit
Motor
Conduit
Curb Cap/Venturi
Windband
Operation
1. Before starting up or operating, check all fasteners
for tightness. In particular, check set screws in
propeller hub. While in the OFF position, or before
connecting the ventilator to power, turn the fan
propeller by hand to be sure it is not striking the
venturi or any obstacle.
2. Start the ventilator up and shut it off immediately
to check rotation of the propeller with directional
arrow in the motor compartment. Ventilator propeller
should rotate counterclockwise on all models when
viewed from the top and clockwise for size 10 only.
3. When the ventilator is started, observe the operation
and check for any unusual noises.
4. With the system in full operation and all ductwork
attached, measure current input to the motor and
compare with the nameplate rating to determine if
the motor is operating under safe load conditions.
5. Keep inlets and approaches to ventilator
clean and free from obstruction.
