Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Catalog No. 04-53480236-01
Printed in U.S.A.
Form 48/50-90SI
Pg 1
3-19
Replaces: 48/50-81SI
Installation Start-Up and Service Instructions
Part No. CRCBDIOX002A00
CONTENTS
Page
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . . 1
GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Check Package Contents . . . . . . . . . . . . . . . . . . . . . . 2
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
48/50A Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
48/50P and 48/50Z Units . . . . . . . . . . . . . . . . . . . . . . . 2
48/50N Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Configuring the ComfortLink Controller . . . . . . . . . . 5
Sensor Self-Calibration . . . . . . . . . . . . . . . . . . . . . . . . 5
SERVICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . 5
SAFETY CONSIDERATIONS
Installation of this accessory can be hazardous due to system
pressures, electrical components, and equipment location (such
as a roof or elevated structure). Only trained, qualified install-
ers and service technicians should install, start-up, and service
this equipment.
When installing this accessory, observe precautions in the liter-
ature, labels attached to the equipment, and any other safety
precautions that apply:
• Follow all safety codes
• Wear safety glasses and work gloves
• Use care in handling and installing this accessory
It is important to recognize safety information. This is the safety-
alert symbol
. When you see this symbol on the unit and in
instructions or manuals, be alert to the potential for personal
injury.
Understand the signal words DANGER, WARNING, CAUTION,
and NOTE. These words are used with the safety-alert symbol.
DANGER identifies the most serious hazards which
will
result in
severe personal injury or death. WARNING signifies hazards
which
could
result in personal injury or death. CAUTION is used
to identify unsafe practices, which
may
result in minor personal
injury or product and property damage. NOTE is used to highlight
suggestions which
will
result in enhanced installation, reliability,
or operation.
GENERAL
The CO
2
sensor (Fig. 1) is designed to monitor carbon dioxide
(CO
2
) levels in the return air and interface with the
Com-
fort
Link controller on the rooftop air-conditioning unit. The
sensor perceives CO
2
levels in the 0 to 2,000 parts per million
(ppm) range and provides outputs indicating this level. The
unit utilizes a 4 to 20-mA analog signal. The
Comfort
Link con-
troller uses this signal to control the economizer damper posi-
tion and ensure adequate level of outside air in the building.
This is one of several approved methods of controlling the in-
door-air quality (IAQ) in a building and meets the requirements
of local building codes and ASHRAE (American Society of
Heating, Refrigerating and Air-Conditioning Engineers) Stan-
dard 62. The control sensor features a membrane-covered
waveguide and sample chamber that produces stable, reliable,
and highly accurate carbon dioxide readings. See Table 1 for
sensor usage.
The sensor is self-calibrating and should not need to be manu-
ally calibrated.
Fig. 1 — CO
2
Sensor
WARNING
Prior to installation of this accessory, make sure all power is
disconnected to the unit and locked out. Failure to disconnect
power supply prior to servicing may result in serious injury.
Table 1 — Sensor Usage
UNIT
SIZE
48/50A
020-060
48/50N2,N3,N4,N5,N6,N7,N8,N9
75-150 tons
48/50P
030-100
48/50ZG,ZN
030-105
50Z2,Z3
030-105
48/50ZT,ZW,Z6,Z8
075-105
50ZX,ZZ,Z7,Z9
075-105
FRONT VIEW
SIDE VIEW
MOUNTING PLATE
48/50A, 48/50N,
48/50P, 48/50Z
CO
2
Sensor Accessory
