Wiring Thermostat - Lennox ComfortSense 7500 Installation And Setup Manual

WIRING THERMOSTAT

Below are the terminal designations and a general
description of their purpose.
1. Connect wiring between thermostat, indoor
and outdoor units.
2. Connect internal and external sensors if
applicable. See information starting on page
11 for sensor wiring and configuring sensor
settings under the Installer Settings menu.
NOTE - Wire run should not exceed 300 feet
(100m).
Seal the hole in the wall with a suitable
3.
material to prevent drafts from entering the
thermostat case.
Configure thermostat and equipment for
4.
system type, program the thermostat, and
test system.
TERMINAL DESIGNATIONS
Ti - Remote indoor temperature sensor
Tc - Sensor common terminal
To - Outdoor or discharge air temperature
sensor
Ec - Economizer/Time-of-Day (TOD)
output-powered via R terminal.
D - Dehumidification relay
W2 - Second-stage heating (non-heat pump) or
fourth-stage (heat pump)
Y2 - Second-stage heating or cooling
O - Cool active reversing valve
B - Heat active reversing valve
C - Common 24VAC
G - Fan relay
W1 - First-stage heating (non-heat pump or
emergency heat) or third-stage heating
(heat pump)
Y1 - Compressor output
R - 24VAC power
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