Lennox ComfortSense 8500 Series Assembly instructions

507611-03
7/2019
Supersedes 11/2018
Installation and Setup
Guide
ComfortSense®8500 Commercial
Programmable Thermostat Series -

2
Table of Contents
Shipping and Packing List..................................3
CS8500 Features..................................................3
Product Dimensions............................................4
Unit Dimensions (H x W x D) ......................................... 4
Wall Plate Dimensions (H x W) ...................................... 4
Wiring Specications..........................................4
Communication Wire ..................................................... 4
Remote Sensor Wire ..................................................... 4
Transformer Wire............................................................ 4
Installation............................................................5
Terminal Connections .........................................6
Purpose.......................................................................... 6
Wiring CS8500 (with or without COSensor)................. 7
Installing Indoor Temperature Sensors ......................... 7
Installing Occupancy Sensor ......................................... 7
iCON™ by Lennox / L Connection
Equipment............................................................8
Network Thermostat Control (NTC) Setup ..................... 8
M1 / M2 Unit Controller Setup........................................ 9
M1 / M2 Unit Controller - Control Mode and
Backup Set Points Setup ............................................... 9
M3 Unit Controller Setup................................................ 9
CS8500 Setup.............................................................. 10
BACnet with M3 Unit Controller.......................10
Network Topology......................................................... 10
CS8500 Set Point Change ........................................... 10
CS8500 Occupancy Override ...................................... 11
BACnet Canceling Override ......................................... 11
Sensor Inputs ............................................................... 11
M3 Unit Controller Setup.............................................. 11
CS8500 Setup.............................................................. 13
CS8500 Sensor Failure................................................ 13
Functions Not Supported ............................................. 13
CS8500 Troubleshooting.............................................. 13
M3 Unit Controller - Setting Return Air
Temperature Limits ...........................................14
Menu ...................................................................14
Technician Settings ...................................................... 14
Parameter Settings Based on System Conguration... 15
Parameter Descriptions................................................ 16
System Status Descriptions.............................19
Error Codes and Reminders.............................23

3
Shipping and Packing List
Verify the following items have been included with
in the packing:
Table 1. Packing List
Quantity Item
1CS8500 (non-zoning) with back
plate
1Wall plate
2Wall anchors
2Screws (M3.5x24mm self-tapping)
1Warranty
1User guide
1Setup and installation guide
WARNING
Improper installation, adjustment, alteration,
service 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
equivalent) or service agency.
CS8500 Features
The ComfortSense®8500 (CS8500) is a commer-
cial, electronic, 7-day, multi-stage, programmable,
touchscreen thermostat. This CS8500 provides
temperature control for packaged gas/electric and
electric/electric for up to 4-heat / 4-cool multi-stage
roof top unit systems (not for heat pump systems).
• Models are available with or without COsensing
capabilities.
• For use with Energence®commercial rooftop
units equipped with Prodigy®.
• For use with iCON Intelligence Connected™ by
Lennox®building-automation solution.
• COmodels can be used to control Lennox’
premium rooftop unit Demand Control Ventilation
features based on COset points and conditions
stored in the unit controller.
The CS8500 also feature enhanced capabilities
    -
cation and control, economizer control and custom
reminders.
• 

• Built-in carbon dioxide monitoring version only


77°F (25°C). Sensor has built-in self-calibration
algorithm.

4
• Temperature monitoring - two internal
thermistors, range 32°F (0°C) to 99°F (37°C).

• External indoor temperature sensor connections

sensor in parallel may be used.
• External occupancy sensor connection (24VAC).
• 
• Maximum load per terminal - 1 amp
• Power supply range 18 to 30 VAC
• 
Product Dimensions
Unit Dimensions (H x W x D)

x 22mm)
Wall Plate Dimensions (H x W)

Wiring Specications
Communication Wire
Use one of the following Lennox communication ca-
bles (twisted pair with shield plenum):
Table 2. Twisted Pair Communication Wiring
(S-Bus - Yellow)
Catalog
Numbers Item
27M19 500 foot roll
 1000 foot roll
 2500 foot roll
CAUTION
This is a 24VAC low-voltage sensor. Do not install
on voltages higher than 30VAC.
Do not short (jumper) across terminals to test
installation. This will damage the sensor and void
the warranty.
Remote Sensor Wire
All remote sensors use standard non-shielded ther-
mostat wiring; 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).
Transformer Wire
Standard thermostat wire (one pair 20 AWG mini-
mum) may be used to wire the CS8500 to the op-
tional wall plug 24VAC transformer (18M13) or other
     -
former.

5
Installation
1. Unpacked the CS8500 and open the case
with a thin-blade screwdriver (see “Figure 1.
Removing Back Plate” on page 5).
2. Place between wall base and unit and twist to
separate unit from base.
Figure 1. Removing Back Plate
3. 

good air circulation at average temperature.
4. Do not install the CS8500 where it can be
󰀨
• Drafts or dead spots behind doors and in
corners.
• Entrance or automatic doors.
• Heat generating equipment such as kitchen
equipment.
• Enclose environment unless a remote indoor
sensor is used.
• Hot or cold air from ducts.
• Radiant heat from sun or appliances.
• Concealed pipes and chimneys.
• Non-heated or non-cooled areas such as an
outside wall behind the sensor.
5. Use the following steps:
a. Determine location using best practices.
b. Use the provided wall plate as a template
to determine location cutout for wiring and
location for wall anchors.
NOTE: The use of the provided wall plate is
optional.
Wall Anchor Locations
Use a level to align wall plate horizontally
Cutout location
for thermostat
wiring
Figure 2. Level Wall Plate
c. Cut or drill a small hole approximately 3/4”
x 3/4” for wiring.
d. Pull about three inches of all wiring through
opening and remove outer communication
wire jacket.
e. Trim 1/4” insulation from end of each wire.
f. 
for wall anchors.


g. Route the CS8500 and outdoor tempera-
ture sensor (optional) wiring from wall
through center openings on wall plate (use
is optional) and back plate (see “Figure 3.

Wall Plate (optional)
Thermostat
Back Plate
Run thermostat wire
through openings
Figure 3. Route Wiring
h. Secure back plate and wall plate (option-
al) to wall with the two provided mounting
screws.
Wall Plate (optional)
Thermostat
Back Plate
Screw
Figure 4. Secure Back Plate
NOTE: Remember to seal the hole in the wall with
a suitable material to prevent drafts from
entering the zone sensor case. Not doing
so could aect the internal temperature
and humidity sensors.
Terminal Connections
External sensors use standard thermostat wiring;
and may be wired using two wires of a multiple wire
cable. Wire run should not exceed 300 feet (100m).
        -
enced in “Table 2. Twisted Pair Communication Wir-
ing (S-Bus - Yellow)” on page 4.
Table 3. Twisted Pair Communication Wiring
(S-Bus - Yellow)
Terminals Purpose
R24VAC
T T External indoor temperature sensor

OC OC Occupancy sensor
 S-Bus communication
C24VAC common
IMPORTANT!
Damage to the ComfortSense 8500 may occur if
24VAC polarity is not maintained.

7
Wiring CS8500 (with or without COSensor)
Below are the terminal designations and a general
description of their purpose.
1. Connect wiring between CS8500 and
applicable controller.
2. Connect external sensors if applicable.
3. Seal the hole in the wall with a suitable material
to prevent drafts from entering the CS8500
case.
4. 
type and test system.
24VAC transformer with
overcurrent protection
required (6.5VA/Zone)
ComfortSense 8500
Figure 5. CS8500 Connections (both versions)
Installing Indoor Temperature Sensors
Wire external sensors as illustrated below. Up to
nine sensors may be used in averaging sensor
     

sensitive.
Figure 6. Temperature Sensor Wiring
(parallel)
The CS8500 will calculate the average temperature
readings from all connected external temperature
sensors. If any of the sensors malfunction, they
may still report a temperature value. Only when the
average value of the connected temperature sen-
sors including any malfunction sensor(s) is lower
than -40°F, or higher than 158°F, will the CS8500
determine that an external temperature sensor(s)
has failed and switch automatically to the CS8500’s
internal temperature sensor. A error message will be
displayed on the home screen and under the noti-
     
sensor” error.
Installing Occupancy Sensor
The occupancy sensor will output:
• 24VAC in occupied mode.
• 0VAC in unoccupied mode.

8
The following is an example on how to make connections for a occupancy sensor.
Figure 7. Occupancy Sensor Connections and 24VAC Transformer
iCON / L Connection Equipment
A single CS8500 can be connected directly to the
S-Bus connection on the Prodigy Unit Controller.
The optional settings (M2 ECTOs or M3 Parame-
ters) can be adjusted using Unit Controller software,
a PC with UC software, and L Connection PC con-
verter.
All parameters can also be set directly at the Unit
Controller. Refer to the applicable unit controller
application guide to edit the required ECTOs or pa-
rameters.
Network Thermostat Control (NTC) Setup
• NTC ECTO A4.07 is factory set to option 0
(local). In this system mode, the NTC will
operate the unit based on input from a local
sensor.
• NTC ECTO A4.07 must be set to option 1
(remote) if an L Connection communication
compatible ComfortSense 8500 is used. In
this system mode, the NTC will operate the unit
based on input from the ComfortSense 8500.

9
M1 / M2 Unit Controller Setup
From the main menu, perform the following naviga-
tion through the menus to set the S-Bus address for
L Connection.
Go to: Settings > Control > Guided Setup > Enter
Advanced Guide Setup > Set Control >
LCONN > ADDR
Enter the S-Bus address for L Connection. Once
done select the Set option to save the settings.
M1 / M2 Unit Controller - Control Mode and
Backup Set Points Setup
The following unit controller ECTOs must be set
when using the CS8500.
ECTO 5.27 - This is use and depends on the avail-
able sensors on the CS8500. Room temperature
reading is standard on all models. The following set-
ting instructs the M1/M2 unit controller what source
to get zone temperature, CO, and indoor RH input.
• 2 = Room temperature (A2)
• 
• 10 = Room temperature and indoor RH (A91)
• 11 = Room temperature, IAQ, and indoor RH
ECTO 6.01        
controller control mode and back-up set points to
use. Options are:
• 1 = Zone sensor mode with no backup.
• 2 = Zone sensor mode with local sensor backup.
• 3 = Zone sensor mode with return air sensor
backup.
M3 Unit Controller Setup
From the main menu, perform the following naviga-
tion through the menus to set the S-Bus address for
L Connection.
1. Go to SETUP > NETWORK INTEGRATION >
L-CONNECTION > LCONN ADDRESS.
2. Enter the desired LCONN ADDRESS (S-Bus)
and select SAVE to continue.
3. Set CONTROL MODE = ROOM SENSOR and
select SAVE to continue.
4. NETWORK SENSOR CO2(if equipped)
needs to be set to YES (if choosing COfrom
CS8500). Select SAVE to continue.
5. RELATIVE HUMIDITY needs to be set to YES
(if choosing RH from CS8500). Select SAVE
to continue.
 TEMPERATURE will need to be set to YES (if
choosing temperature from CS8500).
7.      
questions until it returns you to the NETWORK
INTEGRATION menu option.
NOTE: Once the conguration is saved, then
S-Bus communication will be lost and
alarm 110 (low priority) will be raised. This
will be cleared automatically when any
demand goes to M2/M3.

10
CS8500 Setup
1. From the CS8500’s home screen, go to MENU
> TECHNICIAN SETTINGS and enter 864 and
press OK to proceed.
2. Both the RTU and the CS8500 must be set
to the same S-Bus address. The rooftop
unit’s default address is 2 unless it has been
changed. Set the CS8500 S-Bus address to
match the rooftop unit’s S-Bus address.
3. Set operation with Smart Hub (central hub or
NCP) to ON/OFF.
• If the CS8500 is setup with the rooftop units
with a NCP set this to ON.
• If the CS8500 is setup with the rooftop units
and no NCP set this to OFF.
• If the CS8500 is being used in an iCON by
Lennox automation system with a Central
Hub, set this to ON.
NOTE: It may take 30 seconds up to two minutes
for the CS8500 to connect.
BACnet with M3 Unit Controller
This section describes how a CS8500 operates in a
BACnet environment with a M3 unit controller.
Network Topology
• All rooftop units are connected to the BACnet
front-end.
• Each rooftop unit is connected to one CS8500.
• The CS8500 communicates with the rooftop
units using the Lennox proprietary S-Bus
protocol.
CS8500 Set Point Change
The BACnet front-end provides the occupied and
unoccupied set points to the roof top unit.
The roof top unit (RTU) sends the same set points
to CS8500. The rooftop units uses these set points
until the CS8500 provides a new set point. When the
user changes the set point at the CS8500, it com-
municates the same to M3 unit controller. Upon re-
ceiving this information, the M3 unit controller starts
an override timer and uses the new set points until
the timer expires.
• While the timer is active, if BACnet queries the
M3 unit controller, it will be informed that the
rooftop units is using the override set points.
• When the timer expires, both the M3 unit
controller and CS8500 reverts to the set points
provided by BACnet.