5724452-UIM-A-0619
Johnson Controls Ducted Systems
7
SECTION VII: LOW VOLTAGE CONTROL
CONNECTIONS
The 24 volt power supply is provided by an internally wired low voltage
transformer which is standard on all models. If the unit is connected to a
208 volt power supply, the low voltage transformer must be rewired to
the 208 volt tap. See the unit wiring diagram.
Field supplied low voltage wiring can exit the unit through the top right
(when unit is vertical upflow) or the right side panel. Refer to Figure 5.
Remove desired knockout and pierce foil faced insulation to allow
wiring to pass through. Use as small of a hole as possible to minimize
air leakage. Install a 7/8” plastic bushing in the selected hole and keep
low voltage wiring as short as possible inside the control box.
To further minimize air leakage, seal the wiring entry point at the
outside of the unit.
The field wiring is to be connected at the pigtails supplied with the air
handler. Refer to Figures 12 and 13 for system wiring.
SECTION VIII: BLOWER SPEED
CONNECTIONS
Adjust the blower motor speed to provide airflow within the minimum
and maximum limits approved for indoor coils, electric heat, and
outdoor units. Make speed tap adjustments at the motor terminal block.
See Table 12 for airflow data. Connect the motor wires to the motor
speed tap receptacle for the speed required.
The standard ECM motor operates when a 24 VAC signal is sent to any
of its five speed taps. If simultaneous 24 VAC inputs are present, the
motor operates at the highest speed tap that is energized. The lowest
speed is 1, and the highest speed is 5. The air handler comes factory
wired with the electric heat kit connected to tap 5 for the heating speed,
and the Yellow cooling/heat pump lead connected to tap 4 for the
cooling/heat pump heating speed.
Move the electric heat kit wire for the heating speed from tap 5 to the
appropriate speed tap according to Table 4. If electric heat requires
speed tap 5, the highest speed tap available for cooling/heat pump
heating is tap 4.
The circulating blower (Green) thermostat input is factory connected to
speed tap 1, which is the lowest speed. For applications utilizing multi-
stage outdoor air conditioners or heat pumps, the circulating blower
speed (Green) thermostat input is utilized for the first-stage blower
speed. The circulating blower (Yellow) thermostat input is utilized for
the second-stage or full blower speed. See Figure 15 for wiring details.
FIGURE 9:
Line Power Connections
),(/'32:(5:,5,1*
9
&20321(17&2'(6
*1'*5281'/8*
6'6(59,&(',6&211(&7
&.7&,5&8,7
&1:,5(&211(&725187
*1'
12(/(&75,&+($7
32:(5
6833/<
&1
&1
*1'
-803(5%$5
6,1*/(6285&(32:(5
08/7,6285&(32:(5
08/7,6285&(32:(5
:,7+-803(5%$5
7(50,1$/%/2&.25
6(59,&(',6&211(&7
32:(5
6833/<
32:(5
6833/<
6,1*/(6285&(32:(5
&,5&8,7621N:N:
&,5&8,7621N:
7(50,1$/%/2&.25
6(59,&(',6&211(&7
&.7
&.7
32:(5
6833/<
6'
6'
6'
6'
6'
32:(5
6833/<
*1'
*1'
*1'
*1'
32:(5
6833/<
/
/
/
/
/
/
&.7
/
/
/
/
6'
6'
6'
/
/
/
/
/
/
/
/
/
08/7,6285&(32:(5
&.7
&.7
&,5&8,7621N:N:
&,5&8,7621N:
3+$6((/(&75,&+($7237,216
3+$6((/(&75,&+($732:(5237,216
$
NOTICE
All wiring must comply with local and national electrical code require-
ments. Read and heed all unit caution labels.
NOTICE
It is possible to vary the amount of electric heat turned on during the
defrost cycle of a heat pump. Standard wiring will only bring on the
first stage of electric heat during defrost. See Table 7 for additional
information on heat during defrost cycle.
FIGURE 10:
Blower Speed Connections
GRN
BLOWER
MOTOR
C
L
G
N
RED/WHT
BLK/WHT
TO 230V ON
TRANSFORMER
TO COMMON
ON TRANSFORMER
BLU/WHT
TO RESISTOR
RED
TO RESISTOR
YEL
BLK
STANDARD ECM - HIGH EFFICIENCY MOTOR
A1258-001
1 2 3 4 5
