Carrier 39SH Installation, Start-Up And Service Instructions Manual Download

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START-UP

Check List —

Make a walkway inside unit components to

protect insulation. Remove all construction debris from unit

interior.

Remove walkway before starting unit.

FILTERS — Install unit filters in all filter sections.
FANS

1. Check lubrication of fan, motor bearings, and linkages.

a. Note that bearings are shipped completely full of

grease for corrosion protection and may run warm

temporarily on start-up until excess grease has

discharged.

b. Hand-operate all damper linkages to check for

freedom of movement.

2. Check tightness of bearing setscrews or locking collars.

Also, check tightness of setscrews on fan wheels and

sheaves.

3. Check tightness of fan shaft bearing mounting.
4. Recheck sheave alignment and belt tension. (Refer to

Fig. 49 and 50.)

5. Hand turn fan to make certain fan wheel does not rub in

housing.

6. Check fan speed with a strobe-type tachometer or use the

following formula: Obtain the motor rpm from the fan

motor nameplate and read sheave pitch diameters marked

on the fan and motor pulleys, or estimate the pitch diame-

ters by using the pulley outside diameters.
Then:

Example:

Actual Approximate

Nameplate Motor

Rpm

= 1760

1760

Mtr Sheave Pitch

Diameter

8.9 in.

9.0 (OD)

Fan Sheave Pitch

Diameter

12.4 in.

12.5 (OD)

Fan Rpm

1760 x 8.9

1760 x 9

= 12.4

12.5

1263 Rpm

1267 Rpm

Refer to the product data catalog for maximum allowable

fan speeds for standard wheels.

Excessive fan speed may

result in condensate carryover from cooling coil or fan

motor overload and wheel failure.

7. Check direction of rotation (see Fig. 61). Arrow on drive

side of fan housing indicates correct direction of rotation.

8. Check vibration. If excessive vibration occurs, check for

the following:

a. Variable sheave (if air balance of system has been

accomplished: replace sheave with fixed sheave

for continuous application).

b. Drive misalignment.
c. Mismatched, worn or loose belts.
d. Wheel or sheaves loose on shaft.
e. Loose bearings.
f. Loose mounting bolts.
g. Motor out of balance.
h. Sheaves eccentric or out of balance.
i. Vibration isolators improperly adjusted.
j. Out-of-balance or corroded wheel (rebalance or

replace if necessary).

k. Accumulation of material on wheel (remove

excess material).

SERVICE

General

1. Place a suitable walkway to protect floor insulation

whenever entering the fan section.

2. Review Safety Considerations at beginning of these in-

structions. Good safety habits are important tools when

performing service procedures.

3. To make speed measurements, use a strobe-style tachom-

eter or calculate per Step 6 of Start-Up, Check List.

Fan Motor Replacement

1. Shut off motor power.
2. Disconnect and tag power wires at motor terminals.
3. Loosen motor brace-to-mounting-rail attaching bolts.

Loosen belt tensioning bolts to adjust the motor position

so V-belts can be removed without stretching over

grooves.

4. Mark belt as to position. Remove and set aside belts.
5. Remove motor to motor bracket holddown bolts.
6. Remove motor pulley and set aside.
7. Remove motor.
8. Install new motor. Reassemble by reversing Steps 1-6. Be

sure to reinstall multiple belts in their original position.

Use a complete new set if required. Do not stretch belts

over sheaves. Review the sections on motor and sheave

installation, sheave alignment and belt tensioning dis-

cussed previously (Fig. 48-50).

9. Reconnect motor leads and restore power. Check fan for

proper rotation as described in Start-Up, Check List.

Coil Cleaning

DETERGENT — Spray mild detergent solution on coils with

garden-type sprayer. Rinse with fresh water. Check to ensure

condensate line is free. Excess water from cleaning may flood

unit if condensate line is plugged.