Caution – Carrier 40RU User Manual

Page 25

Individual Fan Wheel Adjustment -- Loosen the 2

locking bolts holding fan wheel hub to shaft. See Fig. 23.

Position fan wheel in center of the fan housing and tighten

locking bolts. Clearance between wheel and housing

should be the same on both sides.

Fan Belts -- Motor mounting plate and motor support

angles are slotted to permit both vertical and horizontal

adjustment. Adjust belt(s) for correct deflection by

loosening motor plate mounting bolts, moving motor/plate

assembly forward or back, and re tightening bolts. Press

down on belt with one finger midway between fan and

motor pulleys to check deflection. For units with motor

sizes up to and including 3.7 Hp (2.76 kW), correct

deflection is

--in. (4.8 mm). For larger motor sizes,

correct deflection is

--in. (3.2 mm). See Fig. 25.

If complete belt replacement is required during servicing,

loosen the motor plate mounting bolts (Fig. 25), move

motor/plate assembly towards fan pulley, and pull belt(s)

off pulleys. Reverse the procedure with new bolts and

readjust deflection.

Fan Rotation -- Correct fan rotation with respect to fan

outlet is shown in Fig. 26.

To reverse the direction of rotation of a 3--phase fan

motor, reverse any 2 of the power leads. Refer to the

connection diagram on the inside of motor terminal box

cover for proper reversing procedure of single--phase

motor.

C10701

Fig. 26 -- Fan Rotation

Fan Pulley Alignment -- Align as follows:

1. Loosen setscrews on pulleys.
2. Align pulleys visually and tighten setscrews on fan

pulley to lock it in place.

3. Use the methods shown in Fig. 27 to check proper

pulley alignment.

C10702

Fig. 27 -- Fan Pulley Adjustments

4. If pulleys are not in correct alignment, loosen the mo-

tor holddown bolts and slide the motor axially until

the pulleys are aligned.

5. Tighten motor holddown bolts.

Pulley and Drive Adjustment -- To obtain desired fan

speed, refer to the fan motor and drive data in Tables

8A--11D and adjust fan motor pulley as follows:

1. Remove belt from fan motor pulley after loosening

motor from motor base.

2. Loosen setscrew in moveable flange of pulley. Screw

moveable flange toward fixed flange to increase the

fan speed and away from fixed flange to reduce

speed. Before tightening setscrew, make certain that

setscrew is over nearest flat surface of pulley hub

(Fig. 27).

UNIT OPERATION HAZARD
Failure to follow this caution could cause equipment

damage.
Increasing fan speed produces a greater load on motor.

Do not exceed rated capacity of motor.

CAUTION

Condensate Drains -- Keep condensate drains free of dirt

and foreign matter.

Return--Air Filters -- Refer to Replacing Filters section

for filter accessibility and removal. Replace with clean

filters of the sizes listed in Tables 1A--1F.

40RU