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3.12.7 DRIVE BELT ALIGNMENT & ADJUSTMENT
Place belt on the groove of the blower sheave and motor sheave to obtain the approx-
imate alignment and belt tension. Remove the belt and align the blower sheave and
motor sheave using a straight edge. When both sheaves are properly aligned, re-install
belt. Do not force or pry the belt onto the sheaves. With the belt in place, adjust so that
all the slack is on one side of the drive. The belt should have from 3/4” to 1” [19 to 25
mm] of slack at 3 lbs. [21 kPa] pressure. Adjust the belt to this tension, by raising or
lowering the swing base via the adjusting rods and nuts.
4.0 START-UP
4.1 PRE-START CHECKLIST
1. Leak test entire system.
2. Check motor mounting to make sure all nuts are tight.
3. Check motor and blower sheaves to make sure they are in proper alignment and set
screws are tight.
4. Check belt tension—belts should be fairly tight for the initial “start-up”.
5. Check bearing—collar set screws on blower shaft to make sure they are tight.
6. Ball type bearings are factory lubricated and do not require additional grease before
starting.
7. Rotate blower shaft by hand to be sure it is free.
8. Check motor and blower rotation.
9. Check all screws, bolts, set screws and piping connections for tightness.
10. Check drain.
11. Insure that filters are in place.
12. Insure all outdoor unit service valves are open.
13. Be sure that electrical controls and motors are properly wired and fused in accor-
dance with applicable codes.
14. Check wheel position in blower housing. See Figures 10A and 10B.
4.2 SYSTEM START-UP & OPERATIONAL CHECK-OUT
• Once everything on the Pre-Start Check-List has been confirmed, turn the electrical
power disconnect on and adjust the thermostat to call for continuous fan operation.
Confirm the blower has the correct rotation and is circulating air in the duct system.
• If the blower is running backwards, disconnect power to the unit and switch two of the
motor leads in the junction box to reverse the motor rotation. Restore electrical power
to the unit and confirm proper blower rotation.
• Confirm the blower is turning the correct RPM using a strobe light or other device
capable of measuring RPM.
• Confirm the full load motor amps listed on the unit data plate are not being exceeded
by more than the 15% service factor rating of the motor.
• If the blower is unusually noisy, disconnect power to the unit and check for improper
alignment of the blower wheel or belt or for something loose.
• If field installed accessories have been installed, confirm proper functioning of those
accessories.
FIGURE 9
FIGURE 10
