Lennox 4SCU23LX Installation Instructions Manual page 15

Fire Hazard. Use of aluminum wire with this product
may result in a fire, causing property damage, severe
injury or death. Use copper wire only with this product.
Thermostat Type Indoor Unit Type
Comfort Sync A3
Comunicating Gas
Communicating
Thermostat
Conventional
24VAC 2-Stage Any Furnace or
Cooling Air Handler (non-
Thermostat (non- communicating)
communicating)
Conventional
24VAC Single- Any Furnace or
Stage Cooling Air Handler (non-
Thermostat (non- communicating)
communicating)
Size Circuit and Install Service Disconnect
Switch
Refer to the unit nameplate for minimum circuit ampacity,
and maximum fuse or circuit breaker (HACR per NEC).
Install power wiring and properly sized disconnect switch.
BOX/BREAKER
SERVICE
DISCONNECT
SWITCH
Figure 7.
NOTE: Units are approved for use only with copper
conductors. Ground unit at disconnect switch or connect
to an earth ground.
508296-01
WARNING
Qty. of
Wires to
Unit
Comfort Sync
4
Furnace or Air
Handler
4
3
Table 6. 4SCU23LX Thermostat Control Options
MAIN FUSE
PANEL
Failure to use properly sized wiring and circuit breaker
may result in property damage. Size wiring and circuit
breaker(s) per Technical Specifications and unit rating
plate.
4SCU23LX
Terminal Strip
Connections
Fully Communicating Variable
R, I+, I-, C Capacity Operation Based Upon
Full Variable Capacity Operation
R, C, Y1, Y2 Controlled by 4SCU23LX Unitary
Control Using Suction Pressure
Full Variable Capacity Operation
R, C, Y1
Controlled by 4SCU23LX Unitary
(Jumper Y1 to Y2)
Control Using Suction Pressure
Install Thermostat
Install room thermostat (ordered separately) on an inside
wall approximately in the center of the conditioned area
and 5 feet (1.5m) from the floor. It should not be installed
on an outside wall or where it can be affected by sunlight
or drafts.
THERMOSTAT
NOTE: 24VAC, Class II circuit connections are made in
the control panel.
Issue 2231
WARNING
Unit Operation
Thermostat Demand
5 FEET
(1.5M)
Figure 8.
Field Wiring
Diagram
Figure 10
Figure 12
Figure 11
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