System Operation - Lennox 13ACX Installation And Service Procedure

ROUTING HIGH VOLTAGE/ GROUND AND CONTROL WIRING
HIGH VOLTAGE / 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 panel.
Connect conduit to the control panel using a proper conduit fitting.
CONTROL WIRING
NOTE — Wire tie provides low voltage control wire strain relief and to
maintain separation of field installed low and high voltage circuits.
NOTE — For proper voltages, select thermostat wire (control wires)
gauge per table above.
NOTE — Do not bundle any excess 24VAC control wires inside
control panel.
Install low voltage wiring from outdoor to indoor unit and from thermostat
to indoor unit as illustrated.
A Run 24VAC control wires through hole with grommet and secure with
provided wire tie.
B Make 24VAC thermostat wire connections. Locate the two wires from the
contactor and make connection using field provided wire nuts:
S
Yellow to Y1
S
Black to C (common)
WIRE RUN LENGTH
LESS THAN 100' (30 METERS)
MORE THAN 100' (30 METERS) 16

System Operation

IMPORTANT
Some scroll compressor have internal vacuum protector
that will unload scrolls when suction pressure goes
below 20 psig. A hissing sound will be heard when the
compressor is running unloaded. Protector will reset
when low pressure in system is raised above 40 psig. DO
NOT REPLACE COMPRESSOR.
The outdoor unit and indoor blower will cycle on and off as
dictated by demands from the room thermostat. When the
thermostat's blower switch is in the ON position, the indoor
blower will operate continuously.
MANUAL HIGH PRESSURE SWITCH (S4) - USED ON
MODELS 13ACX-XXX-230-01 THROUGH -09
Some 13ACX units are equipped with a manual
high‐pressure switch that is located in the liquid line of the
compressor as illustrated in figure on page 2 and figure 13
for the location of the manual reset button.
AWG# INSULATION TYPE
18 TEMPERATURE RATING
35ºC MINIMUM.
HIGH VOLTAGE
CONNECTIONS
(CONTACTOR)
GROUND
HIGH VOLTAGE
FIELD WIRING
LOW VOLTAGE
FIELD WIRING
FACTORY
WIRING
THERMOSTAT
POWER
R
HEAT
W1
COOLING
Y
INDOOR
BLOWER
G
COMMON
C
MANUAL RESET
BUTTON
Figure 13. High Pressure Switch (S4) Manual Reset
The switch is a Single Pole, Single Throw (SPST),
manual-reset switch which is normally closed and
removes power from the compressor when discharge
pressure rises above factory setting at 590 + 10 psi. The
manual-reset button can be identified by a red cap that is
press to preform the reset function.
AUTOMATIC HIGH PRESSURE SWITCH (S4) - USED
ON MODELS 13ACX-XXX-230-10 AND LATER
The 13ACX is equipped with an auto-reset high pressure
switch (single-pole, single-throw) which is located on the
liquid line. The switch shuts off the compressor when
discharge pressure rises above the factory setting. The
switch is normally closed and is permanently adjusted to
trip (open) at 590 + 15 psig (4068 + 103 kPa).
Page 23
SINGLE PHASE
B
CONTROL
WIRING
HIGH VOLTAGE
FLEXIBLE CONDUIT
INDOOR UNIT
AND WIRE TIE
R
OUTDOOR
W
UNIT
Y1
Y
G
C
C
13ACX
A
GROMMET
SERIES