5370939-TIM-C-0518
Johnson Controls Ducted Systems
41
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.
Checking Air Quantity
Method One
1.
Remove the dot plugs from the duct panel (for location of
the dot plugs see Figures 10).
2.
Insert eight-inches of 1/4 inch metal tubing into the airflow
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.
Use an Inclined Manometer or Magnehelic to determine
the pressure drop across a dry evaporator coil. Since the
moisture on an evaporator coil can vary greatly, measuring
the pressure drop across a wet coil under field conditions
could be inaccurate. To assure a dry coil, the compressors
should be de-activated while the test is being run.
Table 19: RPM Selection
Size
(Tons)
Model Airflow Option
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
TA3
(3)
ZV
Field Supplied
1.5
1.5
1VL34
AK79
N/A
465
512
557
606
651
695
Std.
1.5
1.5
1VL40
AK79
N/A
612
661
707
752
799
844
H. Static
1.5
1.5
1VL40
AK61
N/A
782
846
906
968
1022
1085
Field Supplied
1.5
1.5
1VL40
AK54
N/A
896
960
1030
1090
166
1238
TA4
(4)
ZV
Std.
1.5
1.5
1VL34
AK64
N/A
576
631
688
747
800
859
H. Static
1.5
1.5
1VL44
AK69
N/A
792
844
892
944
996
1045
Field Supplied
1.5
1.5
1VL44
AK59
N/A
915
989
1050
1113
1173
1238
TA5
(5)
ZV
Field Supplied
1.5
1.5
1VL40
AK79
N/A
609
656
703
746
792
839
Std.
1.5
1.5
1VL40
AK61
N/A
782
846
906
968
1022
1085
Field Supplied
2
2
1VL40
AK54
N/A
896
960
1030
1090
1166
1238
H. Static
2
2
1VM50
AK64
N/A
1022
1079
1135
1190
1246
1297
Table 20: 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
TA3
(3)
ZV
Std.
1-1/2
1725
0.86
1.15
56
2.4 - 3.4
7/8
1VL40
7.5
1
AK79
H. Static
1-1/2
1725
0.86
1.15
56
2.4 - 3.4
7/8
1VL40
5.7
1
AK61
TA4
(4)
ZV
Std.
1-1/2
1725
0.86
1.15
56
1.9 - 2.9
7/8
1VL34
6
1
AK64
H. Static
1-1/2
1725
0.86
1.15
56
2.8 - 3.8
7/8
1VL44
6.5
1
AK69
TA5
(5)
ZV
Std.
1-1/2
1725
0.86
1.15
56
2.4 - 3.4
7/8
1VL40
5.7
1
AK61
H. Static
2
1725
0.86
1.15
56
3.4 - 4.4
7/8
1VM50
6
1
AK64
Table 21: Power Exhaust Specifications
Model
Voltage
Motor
Unit (Per Circuit)
Fuse Size
CFM @
0.1 ESP
HP
RPM
1
1. Motors are multi-tapped and factory wired for high speed.
QTY
LRA
FLA
MCA
2PE04704706
208/230-1-60
3/4
1075
1
24.9
5
6.3
10
4800
2PE04704746
460-1-60
3/4
1075
1
N/A
2.2
2.8
5
4800
2PE04704758
575-1-60
3/4
1050
1
N/A
1.5
1.9
4
4800
Belt drive blower systems MUST be adjusted to the
specific static and CFM requirements for the application.
The Belt drive blowers are NOT set at the factory for any
specific static or CFM. Adjustments of the blower speed
and belt tension are REQUIRED. Verify proper sheave
alignment; tighten blower pulley and motor sheave set
screws after these adjustments. Re-checking set screws
after 10-12 hrs. run time is recommended.
