5292157-UIM-B-0317
Johnson Controls Unitary Products
13
CONTROL WIRING USING COMMUNICATING
CONTROLS
The Communicating System consists of several intelligent communicat-
ing components including the Hx
TM
Thermostat, the variable speed air
handler and the modulating air conditioner or heat pump. These compo-
nents continually communicate with each other via the wire connections
shown in Figure 15. Commands, operating conditions, and other data
are passed continually between components over the A-R-C-B and A-
C-B bus. The result is a new level of comfort, versatility, and simplicity.
In order to use this air handler, it MUST be installed with the matching
Hx
TM
Thermostat and a matching modulating outdoor air conditioner or
heat pump.
Use the wiring diagram in Figure 15 to connect the air handler control
and the Hx
TM
Thermostat (wall thermostat) to the communicating out-
door unit. Be sure that all of the “A+” terminals are connected together,
all of the “B-” terminals are connected together, all of the “C” terminals
are connected together and both of the “R” terminals are connected
together. See Figure 15 and 16. The four small screw terminals in the
terminal block on the end of the air handler control should be used.
Connect a short piece of thermostat wire (18 gage minimum) to the
ARCB terminals on the air handler control board. Run this wire outside
the control board enclosure. Use wire connectors to connect this wire to
the room thermostat wire and the outdoor unit thermostat wire. The out-
door unit contains its own control transformer. DO NOT run a thermo-
stat “R” wire to the outdoor unit. See Figure 15 for details.
FLOAT SWITCH INPUT
An optional switch may be connected to the FLT terminals on the con-
trol board. This feature is only functional when used with the Communi-
cating Control. It is intended for use with a water overflow switch.
LEAVING AIR TEMP SENSOR INPUT
A plenum air temperature sensor (thermistor) can be connected to the
LAS terminals on the control board. The Communicating Control can
the monitor the temperature of the supply air in the plenum.
SECTION XI: REQUIRED CONTROL
SET-UP
1.
Consult system wiring diagram to determine proper thermostat
wiring for your system.
2.
The Hx
TM
controls the de-humidification during cooling operation
and does not require the HUM STAT jumper to be changed from
NO to YES.
3.
Set the MODE jumper to A/C (Air Conditioner) or HP (Heat Pump)
position depending on the outdoor unit included with the system.
4.
Set HEAT airflow jumper to proper position based on heat kit
installed. Refer to Table 7 for proper position.
FUNCTIONALITY AND OPERATION
Jumper Positions
Hum Stat Jumper
The HUM STAT jumper can be set on the Hx
TM
thermostat. This
function can lower the blower speed for de-humidification during cooling
operation.
AC/HP Jumper
The AC/HP jumper configures the control to operate properly with an air
conditioner (AC position) or heat pump (HP position).
If the jumper is not present, the control will operate as if the jumper is in
the HP position.
Airflow and Comfort Setting Jumpers
The comfort profile is set on the Hx
TM
thermostat. Heat pump and
cooling airflow is set by the outdoor unit.
CAUTION
If any field-supplied wiring is to be connected to the control board,
such as will be the case if the Communicating Control is used or if a
humidistat, float switch or leaving air temperature switch are used,
the additional wires MUST be routed through the hole at the lower left
of the control box. DO NOT add any additional holes to the control
box. After attaching the additional wires to the board, the remaining
hole around the wires must be plugged with the sealant putty supplied
or with a suitable waterproof sealant. FAILURE TO SEAL THIS HOLE
MAY ALLOW WATER TO ENTER THE CONTROL BOX AND DAM-
AGE THE CONTROL BOARD.
FIGURE 15:
Air Handler with Communicating AC or HP
IMPORTANT
Do not place more than one wire under any single communication
terminal screw (there are four communication terminal screws). If
more than one wire must be connected to a terminal screw, attach
only the terminal end of a one wire pigtail, and use a wire connector
to connect the other end of the pigtail to the other wires. Failure to
do this will result in nuisance communication error faults. See Fig-
ure 16.
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FIGURE 16:
Multi-wire Terminal Connection
IMPORTANT
The following steps must be taken at the time of installation to insure
proper system operation.
O
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R UNIT
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nsure
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ire
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ire
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ATING
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A
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237-
001
