507152-01
7/2013
Page 38
THERMOSTAT WIRE TERMINATION IN COMMUNICATING SYSTEM
Indoor Unit
Controller
Outdoor Unit
iComfort Wi-Fi
®
thermostat
Single wire to
terminal C
Single wire to
terminal C
Unused wires
Unused wires
RSBus
Minimum wire size is 18
gauge
Maximum total length of all connections on the RSBus is limited to
1500 ft. (450 m). Max. length between components is 300 ft. (90 m).
Note: iComfort Wi-Fi
®
thermostat does not require shielded cable wiring.
BEST PRACTICES!
Keep all communication wiring as far away from house electric
al wiring and large electrical appliances as possible (15' [5m] recommended).
Communicating systems using the iComfort Wi-Fi
®
thermostat require four
thermostat wires between the thermostat and the furnace/air handler control and
four wires between the outdoor unit and the furnace/air handler control. When a
thermostat cable with more than four wires is used, the extra wires must be properly
connected to avoid electrical noise. The wires must not be left disconnected.
Use wire nuts to bundle the unused wires at each end of the cable. A single wire
should then be connected to the indoor unit end of the wire bundle and attached to
the “C” terminals as shown in the diagram above.
This is not an issue in non-communicating systems.
CONFIGURING HEAT SECTIONS ON AIR HANDLER CONTROL
(AHC)
IMPORTANT: After electric heat strips are installed, the Air Handler Control (AHC)
must be manually configured to detect the number of electric heat sections. (SEE
ALSO 506181-01 for complete configuration guide.)
This procedure is applicable only to the CBX32MV-XX-230-6-06 and higher and
CBX40UHV (all models). To configure the heat strips so that they will be detected by
the thermostat:
Power must be applied to the air handler but NOT to the thermostat. Remove
thermostat from base plate or remove wires to thermostat at the air handler.
On the air handler control (AHC), unit should be in idle mode (decimal blinks
at 1 Hertz—0.5 second ON, 0.5 second OFF.
Select field test mode—press and hold the push button until solid “–” appears;
release button. Display will blink.
Press the push button and wait for the display LED to show “H” (capital H), then
release the button.
The AHC cycles the indoor blower motor “on” to the selected heat speed and
stages the electric heat relays “on” and “off” to automatically detect the
number of electric heat sections. The AHC stores the number of electric heat
sections, then automatically exits “Field Test Mode”.
At this point, the iComfort Wi-Fi
®
will now detect the heat strip information
stored in the AHC.
OUTDOOR
AIR SENSOR
HEAT
1
2 3
4
COOL
1 2
3 4
DELAY
1 2
3 4
ADJUST
NORM
+
ï
HUMIDIFICATION
SMART
AUTO
EVENHEAT
1
2
3 4
BLOWER
ONLY CFM
1
0
0
1
1
5
1
3
0
8
5
Y
1
ï
Y
2
2
ï
ST
A
GE
COMPR
R
ï
O
HE
A
T
PUMP
R
ï
DS
DEHUM
OR
C
W1
W2
G
Y2
Y1
C
R
DH
H
L
O
DS
W3
FUSE
3 AMP
XFMR 24V
24 VAC
COM
3
6
9
1
4
7
XFMR LINE
G
2
5
8
P8
L1
L2
L2 L1
INDOOR
BLOWER
POWER
EARTH
INDOOR BLOWER
SIGNAL
4
5
6
1
2
3
A92
INTEGRATED
CONTROL
OUTDOOR UNIT
LINK
I + I
ï
I + I
ï
R
C
I + I
ï
R
C
THERMOSTAT
HUMIDITROL
DH
DISCHARGE
AIR SENSOR
H
A
RMON
Y
PUSHBUTTON
LED
