Honeywell C7232A Operation manual

PRODUCT DATA
63-2571-4
® U.S. Registered Trademark
Copyright © 2003 Honeywell International Inc.
All Rights Reserved
®
C7232A,B
Sensor and Controller
CARBON DIOXIDE SENSOR
APPLICATION
The C7232 Sensor and Controller is a stand-alone carbon
dioxide (CO2) sensor for use in determining ventilation
necessity with HVAC controllers. The C7232 measures the
CO2concentration in the ventilated space or duct. The C7232
is used in ventilation and air conditioning systems to control
the amount of fresh outdoor air supplied to maintain
acceptable levels of CO2in the space.
FEATURES
• Models available with LCD that provides sensor
readings and status information.
• Non-Dispersion-Infrared (NDIR) technology used to
measure carbon dioxide gas.
• Gold-plated sensor provides long-term calibration
stability.
• Device provides voltage output based on CO2levels.
• Models available with SPST relay output.
• Used for CO2based ventilation control.
• Automatic Background Calibration (ABC) algorithm
based on long-term evaluation reduces required
typical zero-drift check maintenance.
C7232A C7232B
Contents
Application ........................................................................ 1
Features ........................................................................... 1
Specifications ................................................................... 2
Ordering Information ........................................................ 2
Installation ........................................................................ 3
Wiring ............................................................................... 4
Calibration ........................................................................ 6
Checkout .......................................................................... 6
Appendix .......................................................................... 7

C7232A,B SENSOR AND CONTROLLER
63-2571—4 2
ORDERING INFORMATION
When purchasing replacement and modernization products from your TRADELINE® wholesaler or distributor, refer to the
TRADELINE® Catalog or price sheets for complete ordering number.
If you have additional questions, need further information, or would like to comment on our products or services, please write or
phone:
1. Your local Honeywell Automation and Control Products Sales Office (check white pages of your phone directory).
2. Honeywell Customer Care
1885 Douglas Drive North
Minneapolis, Minnesota 55422-4386
In Canada—Honeywell Limited/Honeywell Limitée, 35 Dynamic Drive, Scarborough, Ontario M1V 4Z9.
International Sales and Service Offices in all principal cities of the world. Manufacturing in Australia, Canada, Finland, France,
Germany, Japan, Mexico, Netherlands, Spain, Taiwan, United Kingdom, U.S.A.
SPECIFICATIONS
Models: C7232 Sensor and Controller. A stand-alone carbon
dioxide (CO2) sensor with two jumper-adjustable outputs
(one analog and one spst relay).
C7232A: Wall mount model.
C7232B: Duct mount model.
NOTE: Models are available with or without a 4-digit LCD
that indicates the current CO2concentration.
Dimensions:
C7232A: See Fig. 1.
C7232B: See Fig. 2.
Sensor Performance Ratings:
Response Time: 2 min.
Carbon Dioxide Sensor:
Operation: Non-dispersive infrared (NDIR).
Sampling: Diffusion.
Range: 0 to 2000 ppm ±5% and ±50 ppm.
Annual Drift: 20 ppm (nominal).
Electrical Ratings:
Power Supply: 24 Vac ±20%, 50/60 Hz (Class 2).
Maximum Power Consumption: 3W.
Peak Current (at 20 ms): 600 mA.
Relay:
Configuration: Shipped N.O. (reconfigure with software.)
Contact Rating: 1A at 50 Vac/24 Vdc.
Minimum Permissible Load: 1 mA at 5 Vdc.
Linear Analog Output:
Voltage: 0/2-10 Vdc (resistive load greater than
5000 ohms).
Current: 0/4-20 mA (resistive load less than 500 ohms).
Outputs (Jumper Adjustable, see Table 2):
Analog: 0-10 Vdc (Default: 2-10 Vdc, 500 to 1500 ppm).
Relay: Normally Open Spst (Default: Close at 800 ppm).
Ambient Ratings:
Temperature:
Operating: +32°F to +122°F (0°C to +50°C).
Storage: -4°F to +158°F (-20°C to +70°C).
Relative Humidity (non-condensing): 0 to 95 percent.
CO2Pressure Dependence: 1.4% change in reading per
1 kPa deviation from 100 kPa.
Connections:
Wiring:
C7232A: 20-gauge cable with six 8 in. leadwires.
C7232B: 20-gauge cable with six 6 in. leadwires.
Mounting:
C7232A: Vertical surface with standard single-gang junction
box.
C7232B: Sheet metal duct with a sampling tube.
Automatic Background Calibration (ABC) default: On.
Approvals:
Underwriters Laboratories Inc. Component Recognition:
UL94-5V, File No. E191465.
CE.
C7232A: NEMA1.
C7232B: NEMA3.
Fig. 1. C7232A dimensions in in. (mm).
Fig. 2. C7232B dimensions in in. (mm).
M17540
STANDARD
UTILITY
CONDUIT
BOX
(2X4)
MOUNTING
HOLES
KNOCKOUTS
FOR
EUROPEAN
APPLICATIONS
3-5/32 (80)
2-3/8 (60)
1
(25)
5
-1/16
(128) 2-3/8
(60)
3-5/16 (84) 1-13/16
(46)
1-5/8
(41)
5-5/8
(142)
8 (203)
M17592

C7232A,B SENSOR AND CONTROLLER
3 63-2571—4
INSTALLATION
When Installing this Product...
1. Read these instructions carefully. Failure to follow them
could damage the product or cause a hazardous
condition.
2. Check the ratings given in the instructions and on the
product to make sure the product is suitable for your
application.
3. Installer must be a trained, experienced service
technician.
4. After installation is complete, check out product
operation as provided in these instructions.
IMPORTANT
All wiring must agree with applicable codes,
ordinances and regulations.
CAUTION
Health Hazard.
Improper use can create dangerous situations.
Use in application for sensing carbon dioxide only.
For life-safety applications, this device can function
only as a secondary or lesser device.
CAUTION
Electrical Shock or Equipment Damage Hazard.
Can shock individuals or short equipment
circuitry.
Disconnect power supply before installation.
CAUTION
Equipment Damage Hazard.
Electrostatic discharge can short equipment
circuitry.
Ensure that you are properly grounded before
handling the unit.
C7232A Cover Removal/Replacement
C7232A Cover Removal (see Fig. 3)
1. Remove button head socket cap screw and set it aside.
2. Insert the head of a small screwdriver into the slot at the
center and near the top of the cover.
3. Gently pull the handle down toward the bottom of the
device until a small gap between the subbase and the
cover appears.
4. Remove the screwdriver and pull the cover straight
down until it meets a stop.
5. Pull the cover straight off the subbase.
C7232A Cover Replacement
1. Feed the wires through the opening in the subbase.
2. Place the cover, with a small gap at the top, flat on top
of the subbase.
3. When the cover rests flat on the subbase, slide it
straight up until it latches in place.
Fig. 3. C7232A cover removal.
M17541
B
UTTON HEAD
S
OCKET CAP
S
CREW
ALLEN TOO
L
A
B
C

C7232A,B SENSOR AND CONTROLLER
63-2571—4 4
Location and Mounting
C7232 Sensors mount directly on the wall, sheet metal duct,
or a panel. When planning the installation, allow enough
clearance for maintenance and service. Mount the sensor in a
well-ventilated area.
NOTES: Do not install the sensor where it can be affected by:
— drafts or dead spots behind doors and in corners.
— air from ducts.
Wall Mounting
The C7232 Wall Mount models can be mounted using two or
four screws:
1. Remove C7232 cover.
2. Mount the subbase to the wall using washers and two or
four screws (not supplied) appropriate for the wall
material.
NOTE: When mounting on a junction box, see Fig. 4.
3. Replace the cover.
Duct Mounting (see Fig. 5)
1. Place gasket on aspiration tube.
IMPORTANT
Ensure largest tab at tube control end is at the top.
2. Insert tube into duct; attach using screws and washers.
IMPORTANT
Leakage into the duct or the C7232 box cover from
the room will skew the sensor readings. Ensure the
box cover and duct seal completely.
3. Place o-ring on tube end; mount the control to the tube.
Fig. 4. Junction box mounting (C7232A).
Fig. 5. Duct mounting (C7232B).
WIRING
The factory ships the device with the output default settings
shown in Tables 2 and 3. Set the jumpers and wire the device
(see Table 1 and Fig. 6).
CAUTION
Electrical Shock or Equipment Damage Hazard.
Can shock individuals or short equipment
circuitry.
Disconnect power supply before installation.
CAUTION
Equipment Damage Hazard.
Electrostatic Discharge Can Short Equipment
Circuitry.
Ensure that you are properly grounded before
handling the unit.
IMPORTANT
1. All low voltage connections to this device must be
24 Vac Class 2.
2. All wiring must comply with applicable local codes,
ordinances and regulations.
Table 1. C7232 Wiring Connections (see Fig. 6).
STANDARD UTILITY CONDUIT BOX
M1754
2
SUBBASE
NO. 6 SCREW
NO. 6 SCREW
FRONT
COVER
B
UTTON HEAD
S
OCKET CAP
S
CREW
Wire Color Designation Function
Red G+ 24 Vac Hot
Black G0 24 Vac Common
Yellow OUT1 Analog Output Signal
Brown M Analog Output Common
Orange NO Relay Output Normally Open
Green COM Relay Output Common
M1759
1
FLOW

C7232A,B SENSOR AND CONTROLLER
5 63-2571—4
Fig. 6. Wiring the C7232.
Input Signal
The C7232 Sensors have an adjustable range. These ranges
are determined by the SW1 and SW2 jumper settings (see
Table 2).
Table 2. CO2Range Jumper Settings
aWhen the level reaches this value, the contacts close; when
the level drops 100 ppm below this value, the contacts open.
bSetting when shipped from the factory.
Output Signal
The output signal can be adjusted for 0/2-10Vdc or 0/4-20mA
(see Table 3).
Table 3. Output Signal Jumper Settings
NOTES:
— On duct models, remove the screw holding the
board in place to view jumper settings on reverse.
(See Fig. 7.)
— The CO2settings and the output signal settings
are independent of each other. 0-100% and
20-100% are simply markings for the OUT jumper
settings on the sensor (to differentiate between
the two voltage and the two current ranges) and
do not refer to or alter the ppm range chosen.
Fig. 7. C7232 default jumper settings.
Example
For a CO2setting of 0-2000 ppm and a voltage output of 0-10 Vdc, the output would be as shown in Table 4 (arbitrary points
along the analog curve).
Table 4. 0-10 Vdc Output Example.
For a CO2setting of 0-2000 ppm and a voltage output of 2-10 Vdc, the output would be as shown in Table 5 (arbitrary points
along the analog curve).
Table 5. 2-10 Vdc Output Example.
SW1 SW2 AN (ppm) Relaya(ppm)
On On 0 to 1000 1000
On Off 0 to 2000 1200
OffbOnb500 to 1500 800
Off Off 500 to 2000 1200
L1
(HOT)
L2
M17543
1
1 POWER SUPPLY. PROVIDE
DISCONNECT MEANS AND
OVERLOAD PROTECTION
AS REQUIRED.
C7232
24V
YELLOW
BLACK
RED
BROWN
ORANGE
GREEN
ANALOG
OUT
+
–
AN
OUT
0-100% 20-100%
Voltage 0-10Vdc 2-10Vdc
Current 0-20 mA 4-20 mA
Current Voltage
20 – 100% 0 – 100%
ON OFF
ON OFF
SW2SW1OUT
M19424
AN
CO2Level (ppm) 0 200 400 600 800 1000 1200 1400 1600 1800 2000
VoltageOutput(Vdc)012345678910
CO2Level (ppm) 0 250 500 750 1000 1250 1500 1750 2000
Voltage Output (Vdc) 2 3 4 5 6 7 8 9 10