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II − REFRIGERATION SYSTEM
Units are equipped with single refrigerant circuit (072) or dual refrigerant circuit (090−240). The 090−240 units have a
dual distribution system for two stage capacity control during cooling cycles. Each circuit has its own service valve
connection and expansion valve.
III − BLOWER SPEED & BELT TENSION
Air Volume Adjustment
FIXED PULLEY
BLOWER BELT
ADJUSTABLE
PULLEY
ADJUSTABLE PULLEY
ALLEN SCREW
Run the blower without a cooling demand.
Use the static pressure and rev/min readings to
determine the unit’s air volume (see applicable blower
performance tables).
Measure the indoor blower motor’s rpm.
Measure the static pressure external to the unit.
NOTE − The indoor coil must be dry and the air
filters must be in place when the following
measurements are taken.
Loosen the Allen screw on the adjustable pulley.
Turn the adjustable sheave clockwise to increase the air
volume or counterclockwise to decrease the air volume.
Once the desired air volume has been achieved, tighten
the Allen screw.
1
2
3
4
5
6
7
FIGURE 3
Adjusting Belt Tension
Place belt over all three pulleys.
Using a 15/16" wrench on the
tensioner body nut, apply force until
marks align as shown.
While holding the tensioner in this position,
tighten the mounting bolt to 23 ft−lbs using
a 9/16" wrench.
1
2
3
BELT TENSIONER
FIGURE 4
