288591-BIM-C-0408
Johnson Controls Unitary Products
17
Blower Speed Selection
The variable speed blowers are designed to deliver constant
CFM regardless of the external static pressure (ESP) in the
ductwork. Therefore, if too many supply registers are closed, a
filter becomes clogged, or there is a restriction in the ductwork,
the motor will automatically operate at a higher speed to
compensate for the higher ESP. This may result in a higher
operating sound level.
These units have variable speed motors that automatically
adjust to provide constant CFM from 0.2" to 0.6" w.c. static
pressure. From 0.6" to 1.0" static pressure, CFM is reduced by
2% per 0.1" increase in static. Operation on duct systems with
greater than 1.0" w.c. external static pressure is not
recommended.
To Set Cooling CFM:
Refer to Tables 7 and 8 for the possible cooling and heating
CFM selections.
Find the recommended system airflow for the unit model.
Set desired cooling airflow by moving the jumper on the “Cool”
tap located on the CFM selection board as indicated in Tables
7, 8 and Figure 10.
Airflow may be increased by 10% by moving the “ADJ” jumper
to “B”. Airflow may be decreased by 10% by moving the “ADJ”
jumper to “C”.
NOTE:
CFM indicator light flashes once for every 100 CFM
(i.e., 12 flashes = 1200 CFM).
To Set Delay Profile:
Every unit has multiple cooling “blower off delay” profiles to
optimize system performance and efficiency. Refer to Table
19 for the regional climate in your area. Place the “DELAY”
jumper tap on the CFM selection board to the appropriate pin
setting.
To Set Electric Heat CFM:
The airflow required for Electric Heat may be different than for
cooling.
Refer to Table 10 for the minimum required CFM for the
electric heater installed. Find the desired airflow in Tables 7
and 8. Set the “Heat” Jumper on the CFM selection board to
tap shown.
Table 17: DPX048 Superheat Charging
Outdoor
Temp
(°F)
Superheat at Compressor Suction (°F), Airflow = 1600 CFM
Indoor Wet Bulb Temp (°F)
55
57
59
61
63
65
67
69
71
73
75
65
10.1
10.0
9.9
9.8
9.8
9.7
9.6
9.6
9.7
9.7
9.7
70
9.9
9.8
9.7
9.7
9.6
9.5
9.5
9.5
9.6
9.6
9.6
75
9.7
9.6
9.5
9.5
9.4
9.4
9.3
9.4
9.5
9.5
9.5
80
9.5
9.4
9.4
9.3
9.3
9.2
9.2
9.3
9.4
9.4
9.5
85
9.2
9.2
9.2
9.1
9.1
9.0
9.0
9.1
9.2
9.3
9.4
90
8.8
8.9
8.9
8.9
9.0
9.0
9.1
9.2
9.4
9.5
9.5
95
8.4
8.5
8.6
8.7
8.9
9.0
9.1
9.3
9.5
9.6
9.7
100
8.3
8.4
8.5
8.6
8.7
8.8
9.0
9.2
9.5
9.7
9.8
105
8.3
8.4
8.4
8.5
8.6
8.7
8.8
9.2
9.5
9.7
9.9
110
8.2
8.3
8.4
8.4
8.5
8.6
8.7
9.1
9.5
9.8
10.0
115
8.1
8.2
8.3
8.3
8.4
8.4
8.5
9.0
9.5
9.8
10.1
Table 18: DPY060 Superheat Charging
Outdoor
Temp
(°F)
Superheat at Compressor Suction (°F), Airflow = 1750 CFM
Indoor Wet Bulb Temp (°F)
55
57
59
61
63
65
67
69
71
73
75
65
16.6
16.7
16.8
16.9
17.1
17.2
17.3
17.9
18.4
18.7
19.0
70
16.2
16.4
16.5
16.6
16.7
16.8
17.0
17.4
17.9
18.1
18.4
75
15.9
16.0
16.1
16.2
16.4
16.5
16.6
17.0
17.4
17.6
17.7
80
15.5
15.7
15.8
15.9
16.0
16.1
16.3
16.5
16.8
17.0
17.1
85
15.2
15.3
15.4
15.5
15.7
15.8
15.9
16.1
16.3
16.4
16.5
90
14.0
14.2
14.3
14.4
14.5
14.6
14.8
15.3
15.9
16.2
16.5
95
12.9
13.0
13.1
13.2
13.4
13.5
13.6
14.6
15.5
16.0
16.5
100
12.6
12.8
12.9
13.0
13.1
13.2
13.3
14.3
15.2
15.7
16.2
105
12.4
12.5
12.6
12.7
12.8
12.9
13.0
14.0
14.9
15.4
15.9
110
12.2
12.3
12.3
12.4
12.5
12.6
12.7
13.7
14.6
15.1
15.6
115
11.9
12.0
12.1
12.2
12.2
12.3
12.4
13.4
14.3
14.8
15.3
