Lennox Dave Signature XP21 Installation Instructions Manual page 6

A. ROUTE CONTROL WIRES — NON-COMMUNICATING
Install low voltage control wiring from outdoor to indoor unit and from
thermostat to indoor unit. All low voltage wiring must enter unit through
provided field-installed busing installed in electrical inlet.
Run 24VAC control wires through hole with grommet.
Make 24VAC control wire connections to heat pump control (A175).
NOTE — Do not bundle any excess 24VAC control wires inside control box.
NOTE — Wire tie provides low voltage wire strain relief and maintains
separation of field-installed low and high voltage circuits.
NOTE — For proper voltages, select control wires gauge per table below.
WIRE RUN LENGTH
LESS THAN 100' (30 METERS)
MORE THAN 100' (30 METERS) 16
B. ROUTE CONTROL WIRES — COMMUNICATING
Maximum length of wiring (18 gauge) for all connections on the RSBus is 1500 feet (457 meters). Wires should be color-coded, with a temperature rating
º º
of 95 F (35 C) minimum, and solid-core (Class II Rated Wiring). All low voltage wiring must enter unit through provided field-installed busing installed in
electrical inlet.
Communicating systems using the iComfortt-enabled thermostat require four thermostat wires between the thermostat and the furnace/air handler con­
trol 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 (see illustration below).
Use a wire nut to bundle the four unused wires at each end of the cable. Each bundle should also include an additional wire that should be connected
on each end to the C terminal as shown in the figure below.
iComfortt-enabled
Outdoor Unit
ROUTE HIGH VOLTAGE AND GROUND WIRES
Any excess high voltage field wiring should be trimmed and secured away from any low voltage field wiring. To facilitate a conduit, a
cutout is located in the bottom of the control box. Connect conduit to the control box using a proper conduit fitting.
WATERTIGHT
CONDUIT FITTING
WATERTIGHT
FLEXIBLE CONDUIT
TO SERVICE
DISCONNECT BOX
AWG# INSULATION TYPE
18 TEMPERATURE RATING
35ºC MINIMUM.
Single Wire To C
Terminal
Unused Wires
GROUND LUG*
CONTACTOR
ELECTRICAL INLET (CONTROL WIRING —
LOW VOLTAGE). USE BUSHING
PROVIDED IN BAG ASSEMBLY HERE.
B
iComfortt-enabled
Indoor Unit
CONTROL BOX
ELECTRICAL
INLET (HIGH
VOLTAGE)
WIRING ENTRY
POINTS
FIGURE 6
Page 6
CONTROL
(A175)
HOLE
A
iComfortt-enabled
thermostat
Single Wire To C
Terminal
Unused Wires
* Attach field-provided
green ground wire to
provided ground lug.
NOTE - Grounding wire
must be a single, contin­
uous wire run from unit
ground lug to earth
ground. DO NOT splice
wire.
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