Evaporator Fan Service And Replacement; Belt Tension Adjustment; Evaporator-Fan Motor Replacement - Carrier WEATHERMAKER 48J Started Manual

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CENTER DRIVE
SHAFT
FLEX
MEMBER
SHAFT SHAFT
FLANGE
BEARINGS
7.
8.
Fig. 41 -- Evaporator Fan Coupling
Outside of the unit, assemble the flex members to the cen-
ter drive shaft with 4 bolts and nuts. The flex members
have collars that need to be inserted into the smaller hole
of the drive shaft flange.
Assemble the flex member/drive shaft assembly to one of
the shaft flanges, using 2 bolts and nuts. Slide the other
shaft flange towards the assembly and assemble using
2 bolts and nuts. If the shafts are not misaligned, the collar
in the flex member should line up with the shaft flange
holes.
9. Torque nuts properly to 95 to 100 ft-lb. Do not turn a cou-
pling bolt. Always turn the nut. Always use thread lubri-
cant or anti-seize compound to prevent thread galling.
10. The ends of the shafts should be flush with the inside of
the shaft flange. Torque the set screws to 25 ft-Ib.
11. After assembly is complete, slowly rotate the shafts by
hand for 30 to 60 seconds.
12. Tighten the bearing
mounting bolts, using care not to
place any loads on the shaft which would cause flexure to
the shafts.
13. Reinstall drive belts. (Refer to Belt Tension Adjustlnent
section below.)
14. Visually inspect the assembly. If the shafts are overly mis-
aligned, the drive shaft flange will not be parallel with the
shaft flanges.
15. Recheck nut torque after 1 to 2 hours of operation. Bolts
tend to relax after being initially torqued.
Evaporator Fan Service and Replacement
1. Turn offunit power supply.
2. Remove supply-air section panels.
3. Remove belt and blower pulley.
4. Loosen setscrews in blower wheels.
6. Adjust bolts and nut on mounting plate to secure motor in
fixed position. Recheck belt tension after 24 hours of
operation. Adjust as necessary. Refer to Installation In-
structions for proper tension values.
7. Restore power to unit.
Evaporator-Fan Motor Replacement
1. Turn offunit power supply.
2. Remove upper outside panel and open hinged door to
gain access to motor.
3. Fully retract motor plate adjusting bolts.
4. Loosen the 2 rear (nearest the evaporator coil) motor plate
nuts.
5. Remove the 2 front motor plate nuts and carriage bolts.
6. Slide motor plate to the rear (toward the coil) and remove
fan belt(s).
7. Slide motor plate to the front and hand tighten one of the
rear motor plate nuts (tight enough to prevent the motor
plate from sliding back but loose enough to allow the
plate to pivot upward).
8. Pivot the front of the motor plate upward enough to allow
access to the motor mounting hex bolts and secure in
place by inserting a prop.
9. Remove the nuts from the motor mounting hex bolts and
remove lrlotor.
10. Replace the locktooth washer under the motor base with a
new washer. Be sure that the washer contacts the motor
base surface.
11. Reverse above steps to install new motor.
5. Remove locking collars from bearings.
6. Remove shaft.
7. Remove venturi on opposite side of bearing.
8. Lift out wheel.
9. Reverse above procedure to reinstall fan.
10. Check and adjust belt tension as necessary.
11. Restore power to unit.
Belt Tension Adjustment E To
adjust
belt tension:
1. Turn offunit power supply.
2. Loosen motor mounting nuts and bolts. See Fig. 42.
3. Loosen fan motor nuts.
4. Turn motor jacking bolts to move motor mounting plate
left or right for proper belt tension. A slight bow should
be present in the belt on the slack side of the drive while
running under full load.
5. Tighten nuts.
MOTOR MOTOR
MOUNTING
BOLTS FAN MOTOR NUTS AND
NUTS BOLTS
Fig. 42 -- Belt Tension Adjustment
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