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CBX32MV
Table 8. Air Handler Control Connections
Indoor Control
Terminal Label
Function
Non-Communicating
Room Thermostat
(Indoor and Outdoor -24 volts)
Indoor Communicating
Outdoor Non-Communicating
Full Communication
(Indoor & Outdoor)
W1 (Input)
Indicates a first-stage heating demand.
This input is an anticipator for the ther
mostat.
N/A
N/A
W2 (Input)
Indicates a second-stage heating de
mand.
W1
input must be active to recog
nize second-stage heat demand.
N/A
N/A
W3 (Input)
Indicates a third-stage heating demand.
W1
and
W2
inputs must be active to rec
ognize third-stage heat demand.
N/A
N/A
Y1 & Y2 (Input/
Output)
Room thermostat
inputs
24 volts to the
Y1
and
Y2
terminals on the indoor con
trol. The 24 volt signal is then passed
through to the outdoor unit. During a
second-stage demand, both
Y1
and
Y2
are active. The
Y1
terminal is connected
to
Y2
by link (Solid jumper on control
that would be cut for 2 stage applica
tions)
The room thermostat communicated
with the indoor control. The indoor con
trol
outputs
24 volts on its
Y1
and
Y2
terminals which are hard wired to the
non-communicating outdoor unit.
In a full communicating system, no
wiring is required on
Y1
and
Y2
termi
nals.
G (Input)
Indicates a 24 volt indoor blower de
mand.
In a communicating system, ”G” input to
indoor control is used by non-communi
cating IAQ devices (such as LVCS, HRV
or ERV) to ensure indoor blower de
mand.
In communicating system “G” input to
indoor control is used by non-communi
cating IAQ devices (such as LVCS, HRV
or ERV) to ensure indoor blower de
mand .
C
The C terminal shall interconnect the signal ground of the room thermostat with secondary transformer ground (TR) and
chassis ground (GND )
R
The R terminal shall be capable of providing the power to the thermostat and all the associated loads .
O (Input/Output)
Room thermostat
inputs
24 volts to the
O
terminal on the indoor control. The
O
terminal is connected to
R
by link (Solid
jumper on control that would be cut if
unit was a heat pump)
The room thermostat communicated
with the indoor control. The indoor con
trol
outputs
24 volts on its
O
terminals
which are hard wired to the non-com
municating outdoor unit. If there is 24
volts on
O
, the reversing valve will be
energized and the outdoor unit will run in
the cooling mode. If
O
does not have 24
volts, the outdoor unit will run in heating
mode.
In a full communicating system,
O
termi
nal is not wired.
DS (Input)
Used for Harmony III zoning systems, or
thermostat with dehumidification capa
bility. The
DS
terminal is connected to
R
by link (Solid jumper on control that
would be cut if for the above applica
tions).
Harmony III control
- This will allow the
control to vary the voltage signal to the
indoor blower motor to control required
CFM.
Dehumidification
- Allow a 24 volt sig
nal on the
DS
to turn off and on the dehu
midification mode.
N/A
N/A
DH (Output)
The DH terminal provides a 24VAC
output
for dehumidification needs in communicating systems .
H (Output)
The H terminal provides a 24VAC
output
for humidification needs in both communicating and non-communicating mode .
L (Input)
The
L
terminal is provided for connection to devices with Lennox System Operation Monitor (LSOM) capabilities. The control
interprets the fault signals and transmits them as an alarm message on the communication line. There are ten (10) identified
LSOM fault codes. Each is mapped to the communication Alarm codes.
Table 9. Run Length — Non-Communicating
Wire Run Length
AWG #
Insulation/Core Types
Less than 100' (30m)
18
Color-coded, temperature rating 95
º
F (35
º
C) minimum, solid
core. (Class II Rated Wiring)
More than 100' (30m)
16
