Honeywell Solid State Economizer System Engineering Guide
SYSTEM ENGINEERING GUIDE
63-2576—02
Solid State Economizer System
(CONSISTING OF: C7046C DISCHARGE AIR SENSOR OR C7150B MIXED AIR SENSOR, C7232 OR C7632 CARBON DIOX-
IDE SENSOR, C7400 SOLID STATE ENTHALPY SENSOR OR C7660 SOLID STATE TEMPERATURE SENSOR, M7215
DAMPER ACTUATOR AND W7212, W7213 OR W7214 SOLID STATE ECONOMIZER LOGIC MODULE)
APPLICATION
The Solid State Economizer System provides an economical
method of providing cooling air by incorporating outdoor air in
the first stage of cooling in heating, ventilating and air
conditioning (HVAC) systems. The Solid State Economizer
System consists of the C7046 Discharge Air Sensor, C7150
Mixed Air Sensor, C7232 or C7632 Demand Control
Ventilation (DCV) Sensor, C7400 Enthalpy Sensor or C7660
Dry Bulb Temperature Sensor, M7215 Damper Actuator, and
W7212 Solid State Economizer Logic Module.
FEATURES
C7046C Discharge Air Sensors have probe lengths of 8 in.
(203 mm) and nominal sensor resistance of 3000 ohms at
77°F (25°C).
• No setting or calibration required.
• Solid state components not affected by dust or dirt.
• Fast reacting.
• Rugged aluminum insertion probe.
C7150B Mixed Air Sensor is used with the M7215 Damper
Actuator to sense mixed or discharged air in rooftop packaged
air conditioning equipment.
• No setting or calibration required.
C7232 and C7632 DCV Sensors are stand-alone carbon diox-
ide (CO
2
) sensors for use in determining ventilation necessity
with heating ventilation and air conditioning (HVAC) control-
lers. They measure the CO
2
concentration in the ventilated
space or duct. They are used in HVAC systems to control the
amount of fresh outdoor air supplied to maintain acceptable
levels of CO
2
in the space.
• C7232 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 CO
2
levels.
• C7232 models available with SPST relay output.
• Used for CO
2
based ventilation control.
• Automatic Background Calibration (ABC) algorithm
based on long-term evaluation reduces required
typical zero-drift check maintenance.
• C7632 has fixed 0 to 10 Vdc from 0 to 2000 ppm. No
adjustments are necessary.
(Continued)
W7212/13/14
C7400
M7215
C7150
C7046
C7232B
C7632A
C7660
SOLID STATE ECONOMIZER SYSTEM
63-2576—02 2
C7400 Solid State Enthalpy Sensor and C7660 Solid State
Temperature Sensors are used with the W7212 Solid State
Economizer Logic Module to allow using outdoor air as the
first stage of cooling in HVAC systems.
• C7400 senses and combines temperature and
humidity of outdoor air (heat index).
• C7660 senses dry bulb temperature only.
• Long-lasting, solid state sensing element is accurate
and stable over time.
• When enthalpy/temperature of outdoor air increases,
the outdoor air damper closes to a preset minimum
position.
• When enthalpy/temperature of outdoor air is low, the
outdoor air damper opens to reduce the building
cooling load.
• Provides 4 to 20 mA output signal to the Economizer
Logic Modules; setpoint is located on economizer
control.
• Maximum economizer savings is achieved with two
C7400 Enthalpy Sensors connected to one
Economizer Logic Modules for differential enthalpy
changeover control.
M7215 Damper Motors are 25 lb-in. spring return damper
actuators that provide modulating control of economizer sys-
tems, ventilation dampers and combustion air dampers used
in residential or commercial HVAC equipment.
• M7215 Damper Motors provide modulating control of
economizer dampers from a 2-10 Vdc controller.
• Quiet, high efficiency drive motor.
• High impact, glass-fiber reinforced plastic case is
rugged, lightweight and corrosion resistant.
• Provides 2-10 Vdc output signal proportional to the
shaft position.
W7212 Economizer Logic Modules are used with C7232
Demand Control Ventilation (DCV) Sensors, and solid state
C7400 Enthalpy Sensors or C7660 Dry Bulb Temperature
Sensors to proportion outdoor and return air dampers for con-
trol of free cooling in commercial HVAC equipment.
• Operates from thermostat and DCV sensor to provide a
totally integrated control system.
• Solid state control package provides accurate, reliable
and stable control.
• Mounts on M7215 Motor or duct work.
• Control can be tempered by DCV and fan cycling.
• Used with Honeywell actuators.
• Combines minimum and DCV maximum damper
position potentiometers with compressor staging.
• Relay functions with solid state enthalpy or dry bulb
changeover control.
• Terminals included for switching between Occupied
and Unoccupied operation.
• Terminals included for connecting optional S963B1128
Remote Potentiometer for remote minimum damper
position control.
• LED indicates when free cooling is available.
• LED indicates when module is in DCV mode.
• LED indicates when exhaust fan contact is closed.
• W7213 is used with heat pump B terminal.
• W7214 is used with heat pump O terminal.
IMPORTANT
Specifications given in this publication do not include
normal manufacturing tolerances. Therefore, this unit
may not exactly match the listed specifications. Also,
this product is tested and calibrated under closely
controlled conditions and some minor differences in
performance can be expected if those conditions are
changed.
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.
CAUTION
Electrical Shock or Equipment Damage Hazard.
Can shock individuals or short equipment
circuitry.
Disconnect power supply before installation.
IMPORTANT
All wiring must agree with applicable codes,
ordinances and regulations.
SOLID STATE ECONOMIZER SYSTEM
3 63-2576—02
C7046C DISCHARGE AIR SENSORS
Specifications
Intended for use as a discharge sensor in rooftop applications.
Dimensions: See Fig. 1.
Mounting: Mounting flange requiring two No. 8 screws.
Sensing Element: Carbon type, thermistor-resistor element.
Maximum Ambient Temperature: 250°F (121°C).
Operating Temperature Range: 40 to 150°F (4 to 66°C).
Wiring Connections: 6 in. (152 mm) leadwires.
Performance Characteristics:
Reaction Time Constant with Air Approach Velocity of
500 ft/min (2 m/sec): 60 seconds.
Resistance/Temperature (NTC):
Nominal Resistance: 3000 ohms at 77°F (25°C).
Nominal Sensitivity: 70 ohms per degree F (124 ohms per
degree C) at midrange.
Fig. 1. C7046C Air Temperature Sensor dimensions
in in. (mm).
NOTE: Sensor probe diameter is 1/4 in. (6 mm).
Installation
The sensor assembly (see Fig. 1) consists of an aluminum
sensor probe (element housed internally) with attached flange
that can be mounted on a flat duct or plenum surface, or in
a 2 in. by 4 in. (51 by 102 mm) junction box using two No. 8
screws. Connections to the sensor are made through two 6 in.
(152 mm) leadwires.
LOCATION
The sensor should be located in the air duct or plenum where
it will sample an average air temperature. Avoid locations
where air stratification can cause sensing errors.
MOUNTING
Mounting on a Flat Duct or Plenum Surface (Fig. 2)
1. Cut a 3/8 in. (9.5 mm) hole in the duct or plenum
surface at the desired location.
2. Insert sensor probe into the duct or plenum until the
flange rests against the duct or plenum wall.
3. If necessary, use the flange as a template to mark
and drill two holes for No. 8 mounting screws.
4. Fasten the sensor to the duct or plenum surface
with two No. 8 sheet metal screws (not provided).
Mounting in a Junction Box (Fig. 3)
1. Cut a 3/8 in. (9.5 mm) hole in the duct or plenum
surface at the desired location.
2. Remove the center rear knockout from the junction box
and insert the sensing probe through the knockout with
the flange flat against the outlet box.
3. Using the flange as a template, mark and drill two holes
in the junction box and the duct or plenum surface for
No. 8 mounting screws.
4. Insert sensor probe through both the junction box
knockout and the 3/8 in. (9.5 mm) hole drilled in the duct
or plenum and fasten the junction box and sensor to the
duct or plenum surface.
Fig. 2. Mounting C7046 Air Temperature
Sensor on a flat duct or plenum surface.
Fig. 3. Mounting C7046 Air Temperature
Sensor in a junction box.
1/4
(
6
)
D
IAMETER
(
2 HOLES
)
M224
02
(
25
)
3/4
(
19
)
1-1/2
(
38
)
2
(
51
)
1
(
25
)
1/16
(
2
)
6
(
152
)
8
(
203
)
NE
O
PRENE
G
A
S
KE
T
5/16
(
9
)
DIAMETE
R
(
BUSHING
)
L
OC
KIN
G
P
USH
NUTS
(
2
)
PLA
S
TI
C
BUS
HIN
G
S
EN
SO
R
PR
O
B
E
SYSTEM DUCT
OR PLENUM
FLAN
GE
NO. 8
(
4mm
)
M
OU
NTIN
G
SC
REW
S
(
NOT PROVIDED
)
T
O
APPR
O
PRIAT
E
S
Y
S
TE
M
CO
MP
O
NENT
S
CO
NNE
C
T
S
EN
SO
R
W
IRE
S
WITH TW
O
W
IREN
U
T
CO
NNE
C
T
O
R
S
(
NOT PROVIDED
)
M2240
3
S
EN
SO
R
PR
O
B
E
S
Y
S
TEM
D
UC
T
O
R
PLEN
UM
FLAN
GE
S
TANDARD
U
TILIT
Y
CO
ND
U
IT B
OX
CO
NNE
C
T
OR
L
OC
KN
U
T
CO
ND
U
I
T
FA
C
EPLAT
E
(
OPTIONAL
)
T
O
APPR
O
PRIATE
S
Y
S
TEM
CO
MP
O
NENT
S
CO
NNE
C
T
S
EN
SO
R WIRE
S
WITH TW
O
WIREN
U
T
CONNECTORS
(
NOT PROVIDED
)
NO. 8 (4mm)
MOUNTING
SCREWS (NOT
P
ROVIDED
)
SOLID STATE ECONOMIZER SYSTEM
63-2576—02 4
Wiring
CAUTION
Electrical Shock or Equipment Damage Hazard.
Can shock individuals or short equipment
circuitry.
Disconnect power supply before installation.
CAUTION
Erratic System Operation Hazard.
Failure to follow proper wiring practices can
introduce disruptive electrical interference (noise).
Keep wiring at least one foot away from large inductive
loads such as motors line starters, lighting ballasts,
and large power distribution panels.
Shielded cable is required in installations where these
guidelines cannot be met.
Ground shield only to grounded controller case.
IMPORTANT
1. All wiring must agree with applicable codes,
ordinances and regulations.
2. Do not mount sensor in incorrect environment.
3. Wire according to the applicable controller
instructions.
4. Erratic temperature readings from a sensor can be
caused by improper wiring practices. These must
be avoided to assure proper operation:
•Avoid poor wiring connections.
•Avoid intermittent or missing building earth ground.
•Do not mount sensor in incorrect environment.
Connect low voltage wiring from the sensor to the appropriate
system component terminals using solderless connectors.
See Fig. 3.
Operation
The C7046C Air Temperature Sensors consist of a thermistor
sensing element mounted in a tubular probe. They are applied
at various locations throughout single zone and multizone
duct systems. The negative temperature coefficient (NTC)
characteristic of the thermistor element causes its resistance
to decrease as the sampled air temperature increases. This
resistance shift is balanced with other system sensor signals
by appropriate system logic panels to stabilize system control.
Checkout
Allow the C7046 Air Temperature Sensor to soak in the air
moving through the duct or plenum for a minimum of five
minutes before taking a resistance measurement.
1. Disconnect the sensor leadwires from the associated
system components.
2. Connect an ohmmeter across the leadwires.
3. Assure nominal resistance measurements are in
accordance with the resistance/temperature curves
shown in Fig. 4.
4. Reconnect sensor leadwires to associated system
components.
5. Check operation of the complete control system.
Fig. 4. C7046C Sensor resistance vs. temperature.
4000
3000
2000
1000
8000
7000
6000
5000
12000
11000
10000
9000
16000
17000
15000
14000
13000
605040 70
8010 20 30 90 100
15
2010
25-5
0-10
5
30 35
RESISTANCE (OHMS)
TEMPERATURE (DEGREES)
M17969
F
C
3,000 OHMS
AT 77 F (25 C)
SOLID STATE ECONOMIZER SYSTEM
5 63-2576—02
C7150B MIXED AIR SENSOR
Specifications
Models: See Table 1.
Dimensions: See Fig. 5.
Mounting Arrangement:
Integral mounting flange that requires No. 8 screws.
NOTE: The C7150B1004 requires four No. 8 screws;
the C7150B1046 requires two No. 8 screws.
Ambient Temperature Ratings:
Maximum: 250°F (121°C).
Operating Range: -40 to 110°F (-40 to 43°C).
Shipping Range: -30 to 150°F (-34 to 66°C).
Wiring Connection: 1/4 in. (6 mm) quick-connects.
NOTE: The C7150B1046 includes 4 in. lead wires with
connector for W7340 compatibility.
Table 1. C7150B Models.
a
Negative Temperature Coefficient (NTC).
Fig. 5. C7150B approximate dimensions in in. (mm).
Installation
1. Install on a mounting bracket (not included) inside the
mixed air or discharge air duct using No. 8 mounting
screws and nuts. (See Fig. 6).
NOTE: When mounting, ensure that terminals do not
touch metallic conductive surfaces.
2. Wire using 1/4 in. (6 mm) female quick-connect
terminated wires from C7150B to control inputs.
NOTE: For C7150B1046, splice additional wiring as
needed between sensor and connector.
Fig. 6. Mounting C7150B [C7150B1004 shown].
NOTE: Fig. 6 displays bracket (not included) and suggested
bracket dimensions in in. (mm).
Operation
The C7150B Air Temperature Sensor consists of a thermistor
sensing element mounted on a phenolic board. It is applied in
ventilation duct systems. The thermistor element negative
temperature coefficient (NTC) characteristic causes its
resistance to decrease as the sampled air temperature
increases. This resistance change is used as a control system
sensor to regulate discharge air temperature in a W973 Single
Zone System or damper position of the M7215A Motor (either
directly, or through the Economizer Logic Module).
Checkout
Allow the C7150B Sensor to soak in the air moving through
the duct for a minimum of 5 minutes before taking a resistance
measurement:
1. Disconnect sensor leadwires from associated system
components.
2. Connect an ohmmeter across the leadwires.
3. Nominal resistance measurements should be in
accordance with the resistance/temperature curves
shown in Fig. 7 and Fig. 8.
4. Reconnect sensor leadwires to associated system
components.
5. Check operation of the M7215A Motor, W973 System,
or the Economizer Logic Module.
Model
Nominal Resistance
at 77°F (25°C)
Nominal Sensitivity
a
at midrange
C7150B1004 3000 ohms 70 ohms per °F
(124 ohms per °C)
C7150B1046 10K ohms 234 ohms per °F
(415 ohms per °C)
3
/16
(
5
)
DIAMETE
R
2-1/2
(
64
)
1-1/2
(38)
(
51
)
3/4
(
19
)
3/4
(
19
)
2-3/8
(60)
2-1/4 (57)
M17992
C7150B1004 C7150B1046
NO. 8
MOUNTING
SCREW
TO APPROPRIATE
SYSTEM SENSOR
INPUT
M17938A
DUCT
3/8
(9)
1/2 (13)
2 (51)
SOLID STATE ECONOMIZER SYSTEM
63-2576—02 6
Fig. 7. C7150B1004 Sensor resistance temperature.
Fig. 8. C7150B1046 Sensor resistance temperature.
4000
3000
2000
1000
8000
7000
6000
5000
12000
11000
10000
9000
16000
17000
15000
14000
13000
605040 70
8010 20 30 90 100
15
2010
25-5
0-10
5
30 35
RESISTANCE (OHMS)
TEMPERATURE (DEGREES)
M17969
F
C
3,000 OHMS
AT 77 F (25 C)
10000
5000
20000
15000
25000
605040 70
8020 30 90 100
15
2010
25-5
0
5
30 35
RESISTANCE (OHMS)
TEMPERATURE (DEGREES)
F
C
35000
30000
40000
50000
45000
10,000 OHMS
AT 77 F (25 C)
M20071
SOLID STATE ECONOMIZER SYSTEM
7 63-2576—02
C7232 DCV SENSORS
Specifications
Models: C7232 Sensor and Controller. A stand-alone carbon
dioxide (CO
2
) 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 CO
2
concentration.
Dimensions:
C7232A: See Fig. 9.
C7232B: See Fig. 10.
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 3):
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.
CO
2
Pressure 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:
CE.
Underwriters Laboratories Inc. Listed, File No. E4436.
cUL.
C7232B: Flammability Rating, UL94-5V.
C7232A: NEMA1.
C7232B: NEMA3.
Fig. 9. C7232A dimensions in in. (mm).
Fig. 10. C7232B dimensions in in. (mm).
Installation
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.
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
SOLID STATE ECONOMIZER SYSTEM
63-2576—02 8
C7232A Cover Removal/Replacement
C7232A COVER REMOVAL (SEE FIG. 11)
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. 11. C7232A cover removal.
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. 12.
3. Replace the cover.
DUCT MOUNTING (SEE FIG. 13)
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. 12. Junction box mounting (C7232A).
Fig. 13. Duct mounting (C7232B).
M17541
BUTTON HEAD
SOCKET CAP
SCREW
ALLEN TOOL
A
B
C
STANDARD UTILITY CONDUIT BOX
M17542
SUBBASE
NO. 6 SCREW
NO. 6 SCREW
FRONT
COVER
BUTTON HEAD
SOCKET CAP
SCREW
M17591
FLOW
SOLID STATE ECONOMIZER SYSTEM
9 63-2576—02
Wiring
The factory ships the device with the output default settings
shown in Table 3 and Table 4. Set the jumpers and wire the
device (see Table 2 and Fig. 14).
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 2. C7232 Wiring Connections (see Fig. 14).
Fig. 14. Wiring the C7232.
Operation
Input Signal
The C7232 Sensors have an adjustable range. These ranges
are determined by the SW1 and SW2 jumper settings
(see Table 3).
Tab l e 3 . C O
2
Range Jumper Settings
a
When the level reaches this value, the contacts close;
when the level drops 100 ppm below this value, the con-
tacts open.
b
Setting when shipped from the factory.
Output Signal
The output signal can be adjusted for 0/2-10Vdc or 0/4-20mA
(see Table 4).
Table 4. Output Signal Jumper Settings
NOTES:
— On duct models, remove the screw holding the
board in place to view jumper settings on reverse.
(See Fig. 15.)
— The CO
2
settings 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. 15. C7232 default jumper settings.
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
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
+
–
SW1 SW2 AN (ppm) Relay
a
(ppm)
On On 0 to 1000 1000
On Off 0 to 2000 1200
Off
b
On
b
500 to 1500 800
Off Off 500 to 2000 1200
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
SW2SW1 OUT
M19424
AN
SOLID STATE ECONOMIZER SYSTEM
63-2576—02 10
Example
For a CO
2
setting of 0-2000 ppm and a voltage output of 0-10 Vdc, the output would be as shown in Table 5 (arbitrary points
along the analog curve).
Table 5. 0-10 Vdc Output Example.
For a CO
2
setting of 0-2000 ppm and a voltage output of 2-10 Vdc, the output would be as shown in Table 6 (arbitrary points
along the analog curve).
Table 6. 2-10 Vdc Output Example.
Calibration
Typically, calibration is unnecessary. No calibration kits are
available. However, if CO
2
gas can be purged from the sensor
chamber using a general gas purge device, the sensor can be
rezeroed:
IMPORTANT
Any CO
2
present during calibration skews the sensor
zero level resulting in incorrect CO
2
level reports.
1. Once the sensor stabilizes, use a screwdriver to
connect the two MENU soldering pads.
2. The display should indicate CAL.
3. Execute the zero calibration by connecting the two
ENTER soldering pads.
4. The display should return to providing the measured
CO
2
level.
Checkout
Perform a quick test of the unit with the unit powered:
1. Stand close to the unit and breathe air into the sensor.
2. Check the CO
2
level registered by the controller to
ensure a strong rise.
3. When connected to a damper in a ventilation system,
the controller typically signals an increase in air flow.
CO
2
Level (ppm)
0 200 400 600 800 1000 1200 1400 1600 1800 2000
Voltage Output (Vdc)012345678910
CO
2
Level (ppm)
0 250 500 750 1000 1250 1500 1750 2000
Voltage Output (Vdc) 2 3 4 5 6 7 8 9 10
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