560.20-N1Y
035-16734-000
16
Unitary Products Group
2.
A movable flange with one set screw
After the movable flange has been rotated to the proper num-
ber of “turns open”; the setscrew should be tightened against
the flat on the barrel to lock the movable flange in place. If
the pulley includes a locking collar, the locking collar must be
loosened to adjust the setting of the movable flange.
Note the following:
1.
The supply air CFM must be within the limitations shown
in Table 1.
2.
All pulleys can be adjusted in half turn increments.
3.
The tension of the belt should be adjusted for a deflec-
tion of 3/16 of an inch per foot of belt span with and
applied force of 2 to 3 pounds. Moving the blower motor
mounting plate makes this adjustment. Refer to Figure
8 turning the adjustment bolt (B) moves the motor
mounting plate up or down.
Two hex nuts (A) have to be loosened to move the
mounting plate and retighten after the mounting plate
has been moved to the proper position.
4.
All pulleys are factory aligned.
5.
All supply air motor pulleys are factory set at 2 “turns
open”.
After the supply air blower motor is operating, adjust the
resistances in both the supply and the return duct systems to
balance the supply and the return duct system to balance the
air distribution throughout the conditioned space. The job
specifications may required that this balancing be done by
someone other than the equipment installer.
To check the supply air CFM after the initial balancing has
been completed:
1.
Drill two 5/16-inch holes in the side panel as shown in
Figure 9.
2.
Insert at least 8” of 1/4 inch tubing into each of these
holes for sufficient penetration into the airflow on both
sides of the evaporator coil.
NOTE:The tubes must be inserted and held in a position per-
pendicular to the air flow so velocity pressure will not affect
the static pressure readings. Filters must be removed on the
CED060 to get accurate readings.
3.
Using an inclined manometer, determine the pressure
drop across a dry evaporator coil. Since the moisture on
an evaporator coil may vary greatly, measuring the pres-
sure drop across a wet coil under field conditions would
be inaccurate. To assure a dry coil, The refrigeration
system should be de-activated while the test is being
run.
4.
Knowing the pressure drop across a dry coil, the actual
CFM through the unit can be determined from the curve
in Figure 10.
If the CFM is above or below the specified value, the supply
air motor pulley may have to be re-adjusted. After on hour of
TABLE 12: SUPPLY AIR BLOWER MOTOR PULLEY
ADJUSTMENT
TURNS
OPEN
1
1.
Pulleys can be adjusted in half-turn increments.
BLOWER RPM
DRIVE RPM RANGE AND UNIT SIZE
CED060
810-110
RPM
CED190
655-880
RPM
CED120
700-950
RPM
CED180
625-810
RPM
0
1110
880
950
810
1
1050
835
900
773
2
990
790
850
736
3
930
745
800
699
4
870
700
750
662
5
810
655
700
625
NEVER LOOSEN THE TWO NUTS (C OF FIG-
URE 8) THIS COULD CAUSE THE MOTOR
MOUNT TO LOOSEN AND BREAK THE BELT.
FIGURE 8 : TYPICAL MOTOR MOUNTING
ASSEMBLY
A
M O T O R
M O U N T
B
C ( D O N O T L O O S E N )
M O T O R
