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349218-JIM-F-0512
Johnson Controls Unitary Products
43
Air Balance
Start the supply air blower motor. Adjust the resistances in both
the supply and the return air duct systems to balance the air
distribution throughout the conditioned space. The job
specifications may require 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.
Remove the two 5/16” dot plugs from the blower motor and
the filter access panels shown in the Unit Dimensions and
Rear View Clearances Figure 6.
2.
Insert at least 8" of 1/4 inch tubing into each of these holes
for sufficient penetration into the air flow on both sides of
the indoor coil.
NOTE:
The tubes must be inserted and held in a position
perpendicular to the air flow so that velocity pressure
will not affect the static pressure 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 pressure
drop across a wet coil under field conditions would be
inaccurate. To assure a dry coil, the compressors should
be deactivated while the test is being run.
Table 17: RPM Selection
Size
(Tons)
Model
HP
Max
BHP
Motor
Sheave
Blower
Sheave
6 Turns
Open
5 Turns
Open
4 Turns
Open
3 Turns
Open
2 Turns
Open
1 Turn
Open
Fully
Closed
J15
(15)
ZJ
5
5.75
1VP65
BK110
815
850
885
920
950
985
N/A
5
5.75
1VP65
BK090
1010
1055
1095
1135
1180
1220
N/A
J18
(17.5)
ZJ
5
5.75
1VP60
BK110
730
765
800
835
870
905
N/A
7.5
8.63
1VP60
BK090
905
950
990
1035
1075
1120
N/A
J20
(20)
ZJ
5
5.75
1VP60
BK110
730
765
800
835
870
905
N/A
7.5
8.63
1VP60
BK090
905
950
990
1035
1075
1120
N/A
J25
(25)
ZJ
7.5
8.63
1VP60
1B5V94
810
850
885
920
960
1000
N/A
10
11.50
1VP75X
1B5V110
975
1005
1040
1070
1100
1135
1165
15
17.25
1VP75X
1B5V94
1140
1180
1215
1255
1290
1330
1365
Table 18: Indoor Blower Specifications
Size
(Tons)
Model
Motor
Motor Sheave
Blower Sheave
Belt
HP
RPM
Eff.
SF
Frame
Datum Dia.
(in.)
Bore (in.)
Model
Datum Dia.
(in.)
Bore (in.)
Model
J15
(15)
ZJ
5
1725
0.89
1.15
184T
5.2 - 6.4
1 1/8
1VP65
10.4
1
BK110
BX83
5
1725
0.89
1.15
184T
5.2 - 6.4
1 1/8
1VP65
8.4
1
BK090
BX81
J18
(17.5)
ZJ
5
1725
0.89
1.15
184T
4.2 - 5.5
1 1/8
1VP60
10.4
1 3/16
BK110
BX78
7.5
1725
0.91
1.15
213T
4.2 - 5.5
1 3/8
1VP60
8.4
1 3/16
BK090
BX75
J20
(20)
ZJ
5
1725
0.89
1.15
184T
4.2 - 5.5
1 1/8
1VP60
10.4
1 3/16
BK110
BX78
7.5
1725
0.91
1.15
213T
4.2 - 5.5
1 3/8
1VP60
8.4
1 3/16
BK090
BX75
J25
(25)
ZJ
7.5
1725
0.91
1.15
213T
4.2 - 5.5
1 3/8
1VP60
9.5
1 7/16
1B5V94
BX78
10
1725
0.89
1.15
215T
5.8 - 7.0
1 3/8
1VP75X
11.1
1 7/16
1B5V110 5VX840
15
1725
0.91
1.15
254T
6.2 - 7.4
1 5/8
1VP75X
9.5
1 7/16
1B5V94
5VX860
Table 19: Power Exhaust Specifications
Voltage
Motor
Motor
CFM @
0.1 ESP
HP
RPM
1
1. Motors are multi-tapped and factory wired for high speed.
QTY
LRA
FLA
MCA
208/230-1-60
3/4
1075
1
7.7
5.0
6.25
5250
460-1-60
3/4
1075
1
4.1
2.2
2.75
5250
575-1-60
3/4
1050
1
2.84
1.5
1.875
5250
On VAV units be certain that the VFD drive is set to
maximum output, exhaust dampers are closed and
individual space damper boxes are full open.
VFD units with bypass must not be in bypass mode
(‘LINE’ position) unless all individual space dampers are
full open.