Sensor Connections And Wiring Requirements; Air Handler Control 9-Pin Connector; Control Connections And Wiring Requirements; Discharge Sensor (Dat) - Lennox CBX32MV-018/024 Manual

SENSOR CONNECTIONS AND WIRING
REQUIREMENTS
The following are sensor connections and wiring
requirements for the discharge air and outdoor air sensors.

Discharge Sensor (DAT)

The Air Handler Control has two screw terminals marked
Discharge Air Sensor. The sensor is REQUIRED for
EVENHEAT operation and is field installed and ordered
separately using Lennox Catalog # 88K38.
In the EVENHEAT mode, the discharge air sensor cycles
the electric heating elements as needed to maintain the Air
Handler control EVENHEAT jumper selected discharge
setpoint.
The discharge air sensor should be mounted downstream
of the electric heat elements as illustrated in Figure 26,
Detail A. It must be placed in a location with unobstructed
airflow, where other accessories (such as humidifiers, UV
lights, etc.) will not interfere with its accuracy.
Wiring distance between the Control and the discharge air
sensor should not exceed 10 feet (3 meters) when wired
with 18-gauge thermostat wire.
Outdoor Air Sensor
This is a two screw terminal for connection to a Lennox
X2658 outdoor temperature sensor. The Control takes no
action on the sensor status other than to communicate the
temperature to the RSBus network. Wiring distance
between the Control and outdoor temperature sensor
should not exceed 200 feet when wired with 18-gauge
thermostat wire.
S
Minimum temperature: -40ºF (-40ºC)
S
Maximum temperature: 70ºF (158ºC)
AIR HANDLER CONTROL 9-PIN CONNECTOR (P8)
1. Air Handler (no electric heat) — Two wire factory
harness (wired to pins 7 and 8) which provides 230
VAC power to Air Handler Control.
2. Air Handler (with electric heat) — Eight wire factory
harness (all pin positions are wired as noted in Table 5).
NOTE - See Figure 26, Detail B for wire colors.
CBX32MV
Table 5. Electric Heat Connection (P8)
Position Function / Description
1 Heat stage 1 relay coil
2 Heat stage 2 relay coil
3 Relay coil return
4 Heat stage 3 relay coil
5 Heat stage 4 relay coil
6 Heat stage 5 relay coil
7 L1 230VAC supply from heater kit
8 L2 230 VAC supply from heater kit
9 Not Used
CONTROL CONNECTIONS AND WIRING
REQUIREMENTS
This sections provides information on communicating and
non-communicating control connections and wire run
lengths.
Table 6. Air Handler Control Connections —
Communicating
Label Label
R
i+
Thermostat
i-
C
R
i+
Outdoor Unit
i-
C
i+
Link
i-
Table 7. Run Length — Communicating
Wire Run Length
Maximum length of wiring
for all connections on the
RSbus is limited to 1500
feet (457 meters).
Page 28
Function
24VAC
RSbus data high connection
RSbus data low connection
24VAC command (ground)
24VAC
RSbus data high connection
RSbus data low connection
24VAC command (ground)
Not used.
AWG # Insulation/Core Types
Color-coded, temperature
º º
rating 95 F (35 C) minimum,
18
solid core. (Class II Rated
Wiring)