Air Handler Control Connections; Run Length — Non-Communicating - Lennox CBX32MV-018/024 Manual

Indoor Control
Non-Communicating
Terminal Label
Room Thermostat
(Indoor and Outdoor -24 volts)
Indicates a first-stage heating demand.
W1 (Input) This input is an anticipator for the ther­
mostat.
Indicates a second-stage heating de­
W2 (Input) mand. W1 input must be active to recog­
nize second-stage heat demand.
Indicates a third-stage heating demand.
W3 (Input) W1 and W2 inputs must be active to rec­
ognize third-stage heat demand.
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
Y1 & Y2 (Input/
second-stage demand, both Y1 and Y2
Output)
are active. The Y1 terminal is connected
to Y2 by link (Solid jumper on control
that would be cut for 2 stage applica­
tions)
Indicates a 24 volt indoor blower de­
G (Input)
mand.
The C terminal shall interconnect the signal ground of the room thermostat with secondary transformer ground (TR) and
C
chassis ground (GND )
R The R terminal shall be capable of providing the power to the thermostat and all the associated loads .
Room thermostat inputs 24 volts to the
O terminal on the indoor control. The O
O (Input/Output) terminal is connected to R by link (Solid
jumper on control that would be cut if
unit was a heat pump)
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).
DS (Input) 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.
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 .
The L terminal is provided for connection to devices with Lennox System Operation Monitor (LSOM) capabilities. The control
L (Input) 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.
Wire Run Length
Less than 100' (30m)
More than 100' (30m)
Table 8. Air Handler Control Connections
Function
Indoor Communicating
Outdoor Non-Communicating
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 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.
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.
Table 9. Run Length — Non-Communicating
AWG #
18
16
Page 29
N/A
N/A
N/A
In a full communicating system, no
wiring is required on Y1 and Y2 termi­
nals.
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 .
In a full communicating system, O termi­
nal is not wired.
N/A
Insulation/Core Types
Color-coded, temperature rating 95
core. (Class II Rated Wiring)
Full Communication
(Indoor & Outdoor)
N/A
N/A
N/A
N/A
º º
F (35 C) minimum, solid
CBX32MV