Typical Control Wiring; Low Voltage Wiring - Lennox Merit Series 14HPX Installation Instructions Manual

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
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.
B Make 24VAC thermostat wire connections to CMC1.
NOTE Do not bundle any excess 24VAC control wires inside
control panel.
NOTE For proper voltages, select thermostat wire (control
wires) gauge per Table above.
WIRE RUN LENGTH
LESS THAN 100' (30 METERS)
MORE THAN 100' (30 METERS) 16
HIGH VOLTAGE
FIELD WIRING
LOW VOLTAGE
FIELD WIRING
FACTORY
WIRING
HIGH VOLTAGE
CONNECTIONS
(CONTACTOR)
GROUND
CUTOUT FOR HIGH
VOLTAGE CONDUIT
506377−01 11/09
AWG# INSULATION TYPE
18 TEMPERATURE RATING
35ºC MINIMUM.
SINGLE PHASE
DEFROST CONTROL
A
GROMMET AND WIRE TIE
FOR CONTROL WIRES
Thermostat
R
C
1st. stage aux. heat
W1
indoor blower
G
reversing valve
O
compressor
Y1
NOTE Wire tie provides low voltage wire strain relief and
to maintain separation of field installed low and high voltage
circuits.
Low Voltage Wiring (with Auxiliary Heat)
Thermostat
R
C
BOARD (CMC1)
E
B
W1
1st. stage aux. heat
CONTROL WIRE
CONNECTIONS
G
O
Y1
Page 14

TYPICAL CONTROL WIRING

Low Voltage Wiring

Indoor Unit
power
R
common
common
C
1st. stage aux. heat
W1
W2
W3
G
(SOME CONNECTIONS MAY NOT APPLY. REFER
TO SPECIFIC THERMOSTAT AND INDOOR UNIT.)
Indoor Unit
power
R
common
C
emer.
emergency heat
heat
relay
W1
1st. stage aux. heat
W2
W3
indoor blower
G
reversing valve
compressor
(SOME CONNECTIONS MAY NOT APPLY. REFER TO
SPECIFIC THERMOSTAT AND INDOOR UNIT.)
Outdoor Unit
power
R
C
W1
O
Y1
Outdoor Unit
power
R
common
C
outdoor t'stat
W1
O
Y1