036-33072-001 Rev. A (0601)
16
Unitary Products Group
MOTOR AND PULLEY DATA
TABLE 4: STANDARD BLOWER MOTOR AND DRIVE DATA
TABLE 5:
OVERSIZE BLOWER MOTOR AND DRIVE DATA
BLOWER SPEED ADJUSTMENT
The RPM of the supply air and condenser air blowers will
depend on the required CFM, and the static resistances of
both the supply/discharge and the return/intake duct systems.
With this information, the RPM for the blowers can be deter-
mined from the blower performance tables. Adjustment of
blower speed is accomplished as follows:
a.
Loosen belt tension by moving motor towards the
blower shaft via the adjustable mounting.
b.
Loosen the setscrew in the adjustable motor pulley
flange. Remove external key on pulleys 4 in. dia and
larger.
c.
Slower speed will increase when moveable flange is
adjusted towards the fixed flange (closed). Blower
speed will decrease when the moveable flange is
adjusted away from the fixed flange (opened). Pul-
leys are adjustable only in half-turn increments. Do
not ODen Dullev more than five full turns for "4L"
and "A" belts. or six full turns for "B" belts.
d.
Once the pulley has been opened/closed the appro-
priate number of turns, replace the external key and
tighten the adjustment setscrew. Proper torque is
110-130 in.-Ibs.
e.
Install drive belt and adjust motor mount to tension
belt.
START-UP AND OPERATION
Start unit and check rotation of fans and compressors.
Scroll compressors will only compress in one rotational direc-
tion. Three phase compressors will rotate in either direction
depending upon phasing of the power. Since there is a 50-50
chance of connecting power in such a way as to cause rota-
tion in the reverse direction, it is important to ensure
proper rotation direction is achieved when the system is
installed and operated.
Verification of proper direction is made by observing that suc-
tion pressure drops and discharge pressure rises when the
compressor is energized. Reverse rotation also results in an
elevated sound level as well as substantially reduced current
draw.
Model
Drive Range
(RPM)
Motor
Adjustable
Motor Pulley
Pitch Dia. (in.)
Fixed Blower
Pulley Pitch
Dia. (in.)
Belts
HP
Frame
Size
RPM
Eff.
(%)
Designation
Qty.
CU060
843-1167
1
143
1800
82.5
2.4-3.4
5.2
4L-330
1
CU096
632-875
1-1/2
145
1800
84.0
2.4-3.4
7.0
4L-410
1
CU120
659-913
2
145
1800
84.0
2.4-3.4
6.7
A38
1
CU180
724-925
3
182
1800
86.5
3.4-4.4
8.5
A38
1
CU240
806-1012
5
184
1800
87.5
4.4-5.6
9.9
B60
1
CU300
892-1098
7-1/2
213
1800
88.5
4.9-6.1
9.4
BX60
1
Model
Drive Range
(RPM)
Motor
Adjustable
Motor Pulley
Pitch Dia. (in.)
Fixed Blower
Pulley Pitch
Dia. (in.)
Belts
HP
Frame
Size
RPM
Eff.
(%)
Designation
Qty.
CU060
1034-1432
1-1/2
145
1800
84.0
2.4-3.4
4.2
4L-320
1
CU096
711-984
2
145
1800
84.0
2.4-3.4
6.2
A37
1
CU120
875-1118
3
145
1800
86.5
3.4-4.4
7.0
A40
1
CU180
938-1155
5
184
1800
87.5
4.9-6.1
9.4
A42
1
CU240
1010-1191
7-1/2
213
1800
88.5
5.3-6.3
9.4
B59
1
CU300
1033-1296
10
213
3600
88.5
4.4-5.6
15.4
BX70
1
PRIOR TO STARTING UNIT FOR THE FIRST
TIME, TURN THE THERMOSTAT SYSTEM
SWITCH TO OFF - OR RAISE THE COLLING
SETPOINT TO THE HIGHEST TEMPERATURE
TO PREVENT THE UNIT FROM STARTING,
THEN CLOSE THE ELECTRICAL DISCONNECT
SWITCH.
CAUTION
