TM 9-4120-398-14
This task covers: a . Adjustment
b. Replacement
INITIAL SETUP
Tools
Equipment Condition
Tool kit, refrigeration SVC
Power OFF
Wheel puller
Top panel open, grille removed
General Safty Instructions
WARNING
Voltages used can kill. Always disconnect power
cord to air conditioner before performing any
internal maintenance, Shutting unit off at its
control panel does not disconnect unit power.
NOTE
An unbalanced impeller causes a vibration and noisy operation, Bent or broken blades resulting
in an unbalanced condition require impeller replacements.
a. Removal.
(1) Loosen the two setscrews (1) in the hub of the impeller (2).
(2) Remove the impeller (2) from the motor shaft using a wheel puller, if necessary. Ensure that the drive key
remains in the keyway on the motor shaft.
b. I n s t a l l a t i o n .
(1) Install impeller (2) on the motor shaft. The tips of the blade ends should extend 9/16inch above the venturi at
the airflow exit.
(2) Tighten both setscrews (1).
(3) Install top panel and grille. (See paragraph 4-15.)
If the fan hub rubs against the bolt heads on the motor end bell, lower the motor as described in
c. Adjustment
