Wiring Thermostat; Terminal Designations - Lennox ComfortSense 7500 Installation And Setup Manual

WIRING THERMOSTAT

Thermostat wiring connections with various units,
including dual fuel, zone control, and applications
that include the
Dehumidification Accessory (EDA). See figures 3
through 7. For whole home dehumidifier, refer to
the installation instruction for the dehumidifier.
1. Connect wiring between thermostat, indoor
unit, and outdoor unit as shown in the
appropriate wiring diagram.
2. Connect the outdoor sensor (if used) to the
T connections on the thermostat (wire run
should not exceed 300' [100m]).
3. Seal the hole in the wall with a suitable
material to prevent drafts from entering the
thermostat case.
4. Configure thermostat and equipment for
system type, program the thermostat, and
test system.
®
Humiditrol Enhanced

TERMINAL DESIGNATIONS

Tc - Outdoor Temp. Sensor Connection 1 (Opt.)
To - Outdoor Temp. Sensor Connection 2 (Opt.)
H - Humidification relay (to Humidifier)
D - Dehumidification relay (to DS terminal)
W2 - Second-stage heating (non-heat pump) or 4th
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 - First-stage heating or cooling
R - 24VAC power
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