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.

7
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.

11
TcTi Tc
Ti
Ti Ti
Ti
Tc
Tc
Tc
One sensor
- (1) 47W36
Two sensors -
(2) 47W37
Three sensors -
(2) 47W36 and
(1) 47W37
Four sensors -
(4) 47W36
Five sensors - (3)
47W36 and (2)
47W37
Figure 6. Indoor Sensor Configurations (Option 2, 20K Setting)

12
Residual Cool
Default is 0 seconds. This is the time, in seconds,
that the fan runs after a call for cooling is satisfied in
order to deliver any residual cooling ability from the
coil and ductwork into the conditioned space.
Options are 0, 30, 60, 90 and 120 seconds. Touch <
to return to previous menu.
Low and High Balance Points
These balance points are for heat pump systems
only with an outdoor sensor installed and enabled
plus a indoor unit setting enable. Either gas/oil or
electric will enable the balance point options in the
installer settings list.
1. When in heat mode and the outdoor
temperature is below the programmed Low
Balance Point, then heat pump heating is not
allowed and only backup heat will be used.
2. When in heat mode and the outdoor
temperature is above the programmed High
Balance Point, then heat pump heating is
allowed and backup heat will not be used.
3. When in heat mode and the outdoor
temperature is between the programmed Low
and High Balance Points, then heat pump
heating and backup heat can be used.
4. Options are enable or disable. Default for both
is disable. Once enabled, the following
settings are available.
5. Low Balance Point Default is 25°F. Adjustable
range is -40°F to 48°F.
6. High Balance Point Default is 50°F. Adjustable
range is -38°F to 75°F.
NOTE - The high balance point minimum range is
adjustable to within +2°F of the low balance point
setting. For example, if the low balance point is set to
0°F, then the lowest setting for the high balance point
is 2°F.
Deadband
Default is 2°F. The deadband setting is the minimum
difference between the cooling and heating set
points. This setting is used in cool/heat mode to
ensure smooth equipment operation. The deadband
is adjustable from 2 to 9°F. Use the + or - option to
select desired deadband. Touch <to return to
previous menu.
Smooth Set Recovery(SSR)
Options are enable or disable. Default is Enabled.
When enabled, smooth set recovery begins
recovery up to two hours before the programmed
time so that the programmed temperature is
reached at the corresponding programmed event
time. Assume 12°F per hour for first stage
gas/electric heating and 6°F per hour for first stage
compressor based heating or cooling. With Smooth
Set Recovery disabled, the control will start a
recovery at the programmed time.

13
NOTE - Smooth Set Recovery and SSR STG 2
Lock Out operations vary depending on equipment
(see table 1).
SSR Stage 2 Lock Out
Default is 20 minutes. Use the + or - option to set the
number of minutes before the programmed event
time that stage 2 is allowed to operate (20 to 120
minutes in 10 minute increments). Touch <to return
to previous menu.
Contractor Information
This allows the installer to add contractor name,
address, phone, email, website and number.
Touch <to return to previous menu.
Temperature Offset
Default is 0°F. This setting can be used to offset the
displayed space temperature by up to +/- 5°F. This
offset also applies to the control temperature. Touch
<to return to previous menu.
Humidity Offset
Default is 0%. This can be used to offset the
displayed and controlled space relative humidity
(RH) by up to +/- 10% RH. Touch <to return to
previous menu.
Table 1. Smooth Set Recovery (SSR) & SSR Stage 2 Lock Out Operation
Equipment Available
When SSR is enabled then SSR
Stage 2 lock out is enabled. Can
be set between 20 and 120
minutes. Default is 20 minutes
When SSR is disabled then SSR Stg 2
lock-out setting is disabled.
Single-stage heat pump
with one or two stages
of electric backup
SRun heat pump (Y1) only
SAll backup heat (W1/W2) is
enabled and SSR Stage 2
Lock Out is set between 20 -
120 minutes before the wake-
up set point.
Run heat pump (Y1) and will have
available backup heat (W1/W2) as needed.
Two-stage heat pump
with one- or two-stages
of electric backup
SRun heat pump (Y1/Y2) only.
SAll backup heat (W1/W2) is
enabled and SSR Stage 2
Lock Out is set between 20 -
120 minutes before the
wake-up set point.
Run heat pump (Y1/Y2) and will have avai
lable backup heat (W1/W2) as needed.

14
Equipment Available
When SSR is enabled then SSR
Stg 2 lock out is automatically
enabled.
When SSR is disabled then SSR Stg 2
lock-out setting is disabled.
Single-stage heat pump
with single-stage gas or
oil backup
SRun heat pump (Y1) only
SAll backup heat (W1) is en
abled and SSR Stage 2 Lock
Out is set between 20 - 120
minutes before the wake-up
set point.
SRun heat pump (Y1) until a second-
stage heating demand is needed which
is determined by the time / temperature
differential.
SHeat pump operation will stop and gas
or oil heat will start.
SChangeover and lock-in to W1 heat will
occur until set point reached.
Single-stage heat pump
with:
STwo-stages of gas or
oil backup
SModulation furnace
SRun heat pump (Y1) only
SAll backup heat (W1/W2) is
enabled and SSR Stage 2
Lock Out is set between 20 -
120 minutes before the wake-
up set point.
SRun heat pump (Y1) until a second-
stage heating demand is needed which
is determined by the time / temperature
differential.
SHeat pump operation will stop and
changeover to W1/W2 heat as needed
SLock-in W1/W2 heat until set point is
reached.
Two-stage heat pump
with one stage gas/oil
backup
SRun heat pump (Y1/Y2) only.
SAll backup heat (W1/W2) is
enabled and SSR Stage 2
Lock Out is set between 20 -
120 minutes before the wake-
up set point.
SRun heat pump (Y1/Y2) until a
second-stage demand is needed which
is determined by the time / temperature
differential.
SHeat pump operation will stop and gas
or oil heat will start.
SChangeover and lock-in to W1 heat will
occur until set point is reached

15
Equipment Available
When SSR is enabled then SSR
Stg 2 lock out is automatically
enabled.
When SSR is disabled then SSR Stg 2
lock-out setting is disabled.
Two-stage heat pump
with:
STwo-stages of gas or
oil backup
SModulation furnace
SRun heat pump (Y1/Y2).
SAll backup heat (W1/W2) is
enabled and SSR Stage 2
Lock Out is set between 20 -
120 minutes before the wake-
up set point.
SRun HP (Y1/Y2) until a second-stage
demand is needed which is determined
by the time / temperature differential.
SHeat pump operation will stop and
changeover and lock-in to W1/W2 heat
until set point is reached.
Two stages of gas/oil
heat or modulation
furnace
Run W1 only; W2 is enabled and
SSR Stage 2 Lock Out is set be
tween 20 - 120 minutes before
the wake-up set point.
Run W1 heat and bring on W2 heat until
set point is reached.
Single stage cooling Run Y1 to wake up set point. Run Y1 heat until set point is reached.
Single stage cooling Run Y1 during recovery and en
able Y2 field wake up set point.
Run Y1 and Y2 heat as needed until set
point is reached.
Stage Delay Timer
Default ON. When ON, all stage delay timers
(stages 2, 3, and 4) are enabled and will serve to
bring on additional stage(s) of cooling or heating on
a timed basis (default 20 minutes) in cases when the
previous stage of heating or cooling will not raise or
lower the room temperature to the set point in a
given time. When OFF is selected all stage delay
timers are disabled. This means stages are
changed based on the temperature and not their
timer delays. Scroll to STG DELAY TIMERS; and
touch to select the applicable stage delay timer.
Touch <to return to previous menu.
Stage Delay Differentials
Stage delays and differentials are individual set in
the installer settings screen.
Stage 1 Diff
Stage 1 differential is used in all thermostats. The
default is 1.0°F but can be programmed between
0.5° and 8.0°F in 0.5°F increments. Touch <to return
to previous menu.
Stage 2 Through 4 Diff
(Where applicable) The default is 1.0°F but can be
programmed between 0.5° and 8.0°F in 0.5°F
increments. Touch <to return to previous menu.

16
Stage 2 Through 4 Delays
(Where applicable) If STG DELAY TIMERS is
turned ON, the default delay is 20 minutes but can
be programmed from 5 to 120 minutes in 5-minute
increments. If first stage fails to advance the
ambient temperature toward the setpoint by 1.0°F in
the programmed delay time, then the second stage
is activated.
Scroll to STG 2 DELAY (or 3 or 4); touch to select.
Select the desired delay. Touch <to return to
previous menu.
H/C Stages Locked In
When disabled the heat/cool stages are turned off
separately). When enabled (default), heat/cool
stages are turned off together. Touch <to return to
previous menu.
Stage 2 HP Lock Temp
When disabled the heat pump stage 2 operates
normally). Enable this setting in dual fuel
applications to lock in the 2nd stage compressor
when the outdoor temperature is at or less than the
LOCK TEMP set point. Scroll to STAGE 2 HP LOCK
TEMP; touch ENTER. Use - + option to select a
LOCK TEMP between -40 and 75ºF. Touch <to
return to previous menu.
Configuration Figures
Multi-stage Cooling for Heat Pump/Non-Heat Pump 7
Heating - Non-Heat Pump (1 or 2 stages) 8
Heating - Heat Pump with NO backup heat 10
Heating - Heat Pump w/electric heat (2-stage: 1compr/1backup) 10
Heating - Heat Pump w/electric heat (3 stage: 2compr/1backup) 11
Heating - Heat Pump w/electric heat (3 stage: 1compr/2backup) 11
Heating - Heat Pump w/electric heat (4 stage: 2compr/2backup) 12
Heating - dual fuel (2-stage: 1compr/1backup) 13
Heating - dual fuel (3 stage: 1compr/2backup) 14
Heating - dual fuel (3 stage: 2compr/1backup) 15
Heating - dual fuel (4 stage: 2compr/2backup) 16

17
H/C
Stages
Locked =
YES
H/C
Stages
Locked =
NO
SET
POINTS:
2nd stage
ON
2nd stage
OFF
1st stage
ON
1st stage
OFF
2nd stage
ON
2nd stage
OFF
1st stage
ON
1st stage
OFF
SP -1.5 SP -1.0 SP -0.5 SP SP +1.5SP +1.0SP +0.5 SP +2.0
Stg1 Differential
Stg2 Differential
Stg2 Differential
Stg1 Differential
Figure 7. Cooling - 1 or 2 Stages
H/C
Stages
Locked =
YES
H/C
Stages
Locked =
NO
1st stage
ON
2nd stage
ON
1st stage
ON
2nd stage
ON
2nd stage
OFF
1st stage
OFF
1st stage
OFF
2nd stage
OFF
SP -1.5 SP -1.0 SP -0.5 SP SP +0.5SP -2.0
Stg1 Differential
Stg2 Differential
SP -2.5SP -3.0
Stg1 Differential
Stg2 Differential
SET
POINTS:
Figure 8. Heating - Non-Heat Pump or Heat Pump w/o Backup Heat - 1 or 2 stages

18
H/C
Stages
Locked =
NO
H/C
Stages
Locked =
YES
SET
POINTS:
3rd stage
ON
1st stage
ON
2nd stage
ON
3rd stage
ON
1st stage
ON
2nd stage
ON
2nd stage
OFF
3rd stage
OFF
1st stage
OFF
1st stage
OFF
2nd stage
OFF
3rd stage
OFF
SP -1.5 SP -1.0 SP -0.5 SP SP +0.5SP -2.0
Stg1 Differential
Stg3 Differential
Stg2 Differential
SP -2.5SP -3.0SP -3.5
Stg1 Differential
Stg3 Differential
Stg2 Differential
Figure 9. Heating - Heat Pump w/Electric - 3 Stage (2 compressor / 1 backup OR 1 compressor /
2 backup)

19
H/C
Stages
Locked =
YES
H/C
Stages
Locked =
NO
3rd stage
ON
1st stage
ON
2nd stage
ON
4th stage
ON
3rd stage
ON
1st stage
ON
2nd stage
ON
4th stage
ON
2nd stage
OFF
3rd stage
OFF
4th stage
OFF
1st stage
OFF
Stg4 Differential
1st stage
OFF
2nd stage
OFF
3rd stage
OFF
4th stage
OFF
SET
POINTS: SP -1.5 SP -1.0 SP -0.5 SP SP +0.5SP -2.0
Stg1 Differential
Stg3 Differential
Stg2 Differential
SP -2.5SP -3.0SP -3.5
Stg1 Differential
Stg3 Differential
Stg2 Differential
Stg4 Differential
Figure 10. Heating - Heat Pump w/Electric - 4 Stage (2 compressor / 2 backup)
H/C
Stages
Locked =
NO or
YES
2nd stage
ON
1st stage
ON
2nd stage
OFF
1st stage
OFF
SP -1.5 SP -1.0 SP -0.5 SP SP +0.5SP -2.0
Stg1 Differential
SP -2.5SP -3.0
Stg2 Differential
SET
POINTS:
Figure 11. Heating - Dual Fuel - 2 Stage (1 compressor / 1 backup)

20
H/C
Stages
Locked =
NO
H/C
Stages
Locked =
YES
SET
POINTS:
3rd stage
ON
1st stage
ON
2nd stage
ON
3rd stage
ON
1st stage
ON
2nd stage
ON
2nd stage
OFF
3rd stage
OFF
1st stage
OFF
1st stage
OFF
2nd stage
OFF
3rd stage
OFF
SP -1.5 SP -1.0 SP -0.5 SP SP +0.5SP -2.0
Stg1 Differential
Stg3 Differential
Stg2 Differential
SP -2.5SP -3.0SP -3.5
Stg1 Differential
Stg3 Diff.
Stg2 Differential
Figure 12. Heating - Dual Fuel - 3 Stage (1 compressor / 2 backup)
H/C
Stages
Locked =
NO
H/C
Stages
Locked =
YES
SET
POINTS:
3rd stage
ON
1st stage
ON
2nd stage
ON
3rd stage
ON
1st stage
ON
2nd stage
ON
2nd stage
OFF
3rd stage
OFF
1st stage
OFF
1st stage
OFF
2nd stage
OFF
3rd stage
OFF
SP -1.5 SP -1.0 SP -0.5 SP SP +0.5SP -2.0
Stg1 Differential
Stg3 Differential
Stg2 Differential
SP -2.5SP -3.0SP -3.5
Stg1 Differential
Stg3 Differential
Stg2 Differential
Figure 13. Heating - Dual Fuel - 3 Stage (2 compressor / 1 backup)