Lennox ComfortSense 7500 Assembly instructions

ComfortSense®7500 Commercial 507506-02
6/2018
Supersedes 5/2017
Installation and Setup Guide

2
Table of Contents
Shipping and Packing List 2...............
Description 2...........................
Installation 3............................
Menu 8................................
Installer Settings 9.......................
Dehumidify Mode 24......................
Economizer 26...........................
Unit Part (Catalog) & Serial Numbers 27......
Memory Protection 27.....................
Start-Up Sequence of Operations 28.........
Diagnostic Information 29..................
Reminder Information 32...................
Supported Configurations 33...............
Installation Checklist 34....................
Shipping and Packing List
1 - ComfortSense
®7500 touchscreen, 7-day
programmablethermostat with back plate
1 - Wall plate
2 - Mounting screws (M3.5x25mm self-tapping
screws)
2 - Wall anchors
1 - Warranty sheet
1 each - User and Installer Guides
Description
The ComfortSense®7500 commercial thermostat is
an electronic 7-day universal multi‐stage
programmable touch screen thermostat. It also
offers enhanced capabilities which include:
Sdehumidification measurement and control,
Sequipment maintenance reminders,
Sworry-free memory storage feature,
Smenu-driven touch-screen display.
This thermostat supports heat pumps (single or two
stage) or non-heat pump units, with up to:
Stwo auxiliary stages
Stwo stages of heating and two stages of
cooling.
SEconomizer support
Unit Dimensions (H x W x D)
Case dimensions: 3-5/16 x 4-5/16 x 7/8 in. (84 x 110
x 22mm)
Wall Plate Dimensions (H x W)
Plate dimensions: 4-1/2” x 5-3/4” (114 x 146mm)
Compressor Short Cycle Protection
This thermostat is equipped with automatic
compressor protection to prevent potential damage
due to short cycling or extended power outages.
The short-cycle protection provides a 5-minute
delay between heating or cooling cycles to prevent
the compressor from being damaged.
A 5-minute compressor short cycle protection timer
begins when a compressor output is de-energized.

3
Also, if a power loss occurs, the system will go into
compressor protection mode and display “waiting”
next to either a snow flake (compressor cooling), or
flame (compressor heating) in the display.
Internal and External Temperature Sensors
See information starting on page 9 for sensor
wiring and configuring sensor settings under
Installer Settings menu.
WARNING
Improper installation, adjustment, alteration, ser
vice or maintenance can cause property damage,
personal injury or loss of life.
Installation and service must be performed by a
licensed professional HVAC installer (or equiva
lent) or service agency.
WARNING
Always turn off power at the main power source
by switching the circuit breaker to the OFF posi
tion before installing or removing this thermostat.
All wiring must conform to local and national build
ing and electrical codes and ordinances.
CAUTION
This is a 24VAC low-voltage thermostat. Do not
install on voltages higher than 30VAC.
Do not short (jumper) across terminals on the gas
valve or at the system control to test installation.
This will damage the thermostat and void the war
ranty.
Installation
Before beginning installation, note the type of
equipment,number of stages, and any accessories
being installed. This thermostat is a 24VAC
low-voltage thermostat and requires a common wire
to the thermostat to operate.
DO
SShut off all power to system before
installing.
SRead this entire document, noting which
instructions pertain to your equipment and
system requirements.
SMake sure that all wiring conforms to local
and national building and electrical codes and
ordinances.
SUse thermostat wire between the
thermostat and any optional remote

4
temperature sensor (may be separate wire
pair or two wires of a multi-wire cable for
outdoor temperature sensor).
SEnsure load from any thermostat
connection is less than 1 AMP.
DO NOT
SInstall On voltages higher than 30VAC.
SShort (jumper) across terminals on the gas
valve or at the system control to test
installation. This will damage the thermostat
and void the warranty.
SInstall on outside walls or in direct sunlight.
SExceed thermostat wire run length
greater than 300 feet (91m).
Hardware Installation
1. Unpacked the thermostat and open the case
with a thin-blade screwdriver. Place between
wall base and unit and twist to separate unit
from base.
2. Select a location for the thermostat about 5 feet
(1.5m) above the floor in an area with good air
circulation at average temperature.
3. Do not install the thermostat where it can be
affected by:
SDrafts or dead spots behind doors and
in corners.
SNot close to entrance or automatic
doors.
SNot close to heat generating equipment
such as kitchen equipment.
SNot in an enclose environment unless a
remote indoor sensor is used.
SHot or cold air from ducts.
SRadiant heat from sun or appliances.
SConcealed pipes and chimneys.
SUnheated (uncooled) areas such as an
outside wall behind the thermostat.
Figure 1. Removing Back Plate
4. Use steps Athrough J (step Japplicable when
using provided wall plate) to install the
thermostat.

5
CUT OR DRILL A SMALL HOLE
FOR THERMOSTAT WIRING
¾” x ¾”
A
B
PULL ABOUT 3” OF THERMOSTAT
WIRE THROUGH OPENING AND RE
MOVE OUTER THERMOSTAT WIRE
JACKET.
THIS WILL HELP IN
ROUTING THE THER
MOSTAT WIRING TO
THE PROPER THER
MOSTAT TERMINALS
1/4”
TRIM 1/4” INSULATION FROM
END OF EACH WIRE
C
USE UNIT WALL PLATE AS TEMPLATE TO MARK
DESIRED MOUNTING HOLE LOCATIONS ON WALL
D
(USE A LEVEL) ALIGN WALL PLATE
DRILL 3/16” HOLES AT MARKED LOCATIONS
ON WALL FOR WALL ANCHORS
E
NOTE: INSTALLATION OF WALL PLATE
IS OPTIONAL.

6
Thermostat Installation with Wall Plate
F- Place wall plate
over holes in wall.
G- Insert wall anchors
through wall plate into wall.
H - Attach back plate
to wall plate.
I- Insert provided screws through back and wall
plates into wall anchors.
J- Attach thermostat to
back plate.
Thermostat Installation without Wall Plate
G- Place back plate over wall
anchors in wall.
F- Insert wall anchors
through wall plate into wall.
H- Insert provided screws through
back plate into wall anchors.
I- Attach thermostat to
back plate.

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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
9 for sensor wiring and configuring sensor
settings under the Installer Settings menu.
NOTE - Wire run should not exceed 300 feet
(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.
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/B - Heat/Cool active reversing valve
F - Economizer or other fault detection
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
IMPORTANT
In all applications, the commercial version of the
ComfortSense
®Model 7500 thermostat can only
be used if the following installation criteria is met:
Sinstallation uses 18 GAUGE thermostat
wire or larger,
Sthermostat wire run length DOES NOT EX
CEED 300' (91m),
Sload from any thermostat connection is 1
AMP or LESS.

8
Settings
menu
performance report
notifications 13
edit schedules
settings
Figure 2. Menu Screen
Menu
1. Touch menu option from the home screen.
2. Touch and hold the settings option on the
menu. This will display the installer settings
notice and then the installer settings menu.
installer settings
confirm
<
installer settings must be set
by qualified person.
Figure 3. Installer Menu Screen Confirmation

9
Installer Settings
Sets the thermostat for operation with either a heat
pump or condenser unit and defines the number of
compressor stages and the number of backup heat
stages (gas, electric or both).
system settings
compressor settings
indoor unit settings
no heat
<
non heat pump
heat pump
compressor stage
indoor heat stage


+
+
1
1
electric
gas/oil
Figure 4. System Setup
Sensors Settings
Use the following information to install sensors and
setup in the user interface.
Indoor Outdoor
outdoor sensor
indoor sensor
remote 10k
remote 20k
<
outdoor
discharge air
none

internal
Figure 5. Sensor Selections

10
Outdoor Sensor (small commercial split systems
only)
An outdoor temperature sensor (X2658) is required
for balance points and Humiditrol®unit operations.
Users has three options to select from (under
Installer Settings > sensor settings > outdoor
sensor):
SOption 1 is using a outdoor temperature
sensor (X2658) (default). Sensor connects to
To and Tc terminals on the thermostat.
SOption 2 is using a discharge air temperature
sensor (19L22). Connects to To and Tc
terminals on thermostat. This sensor is a
non-adjustable duct mount temperature
sensor.
NOTE - The outdoor sensors use standard
non-shielded thermostat wiring; it may be wired
using two wires of a multiple wire cable.
Indoor Sensors (remote temperature room
sensor)
This thermostat can support one to five remote
indoor temperature sensors. Users have three
options to select from under Installer Settings >
sensor settings > indoor sensor:
SOption 1 is remote 10k (47W37)
SOption 2 is remote 20k (47W36)
SOption 3 is internal (default)
NOTE: Both external sensors are purchase
separately. Wiring examples for up to five sensors
are illustrated in figure 6 on page 11. All examples
shown result in Option 2, 20k setting.
For detail installation requirements and procedure,
refer to the instructions provided with either kit.
Thermostat terminals Ti and Tc are used for indoor
sensor(s).
NOTE - All remote sensors use standard
non-shielded thermostat wiring; outdoor sensors
may be wired using two wires of a multiple wire
cable.
NOTE - Outdoor and indoor sensor wire runs
should not exceed 300 feet (100m).
NOTE: The discharge air sensor is for monitoring
and display only. There is no control based on input
from this sensor.