The Trane Company
3600 Pammel Creek Road
La Crosse, WI 54601-7589
© 2002 American Standard Inc.
3270 3361 Rev 1
®
CO
2
Demand-Controlled Ventilation Wall-Sensor
Ordering number: 4190 4100
The carbon-dioxide (CO
2
) sensor, shown in Figure 1,
is designed especially for demand-controlled
ventilation zone applications. The exceptional
stability and reliable performance come from
advanced silicon based Non-Dispersive InfraRed
(NDIR) technology.
Figure 1:
CO2 demand-controlled ventilation sensor
Specifications
Table 1 shows the specifications of the CO
2
sensor.
Power supply requirements
CAUTION
AVOID EQUIPMENT DAMAGE!
Make sure that you connect the power wire only to
the 24V terminal. Connecting the power wire to the
output terminal may result in equipment damage.
The CO2 sensor is designed to operate with a
nominal 24 Vac supply. The power supply should
maintain the voltage between 20 to 26 Vac.
Use a 24 Vac power supply according to the following
guidelines. If more than one sensor is connected to
one 24 Vac transformer, a common loop is formed
and the risk of a short-circuit increases. To avoid
this, use a separate floating supply for each sensor,
as shown in Figure 2.
Figure 2:
Separate ac power supplies
Table 1:
Sensor specifications
Measuring range
0–2000 parts per million (ppm)
CO
2
Accuracy at 25°C
< ± [40 ppm CO
2
+ 3% of
reading] (includes repeatability
and calibration uncertainty)
Non-linearity
< 1.0% full scale (FS)
Temperature
dependence of output
0.3% FS/°C
Long-term stability
< 5.0% FS/5-years
Recommended
calibration interval
5 years
Response time
1 minute (0–63%)
Operating temperature
From 59 to 95°F (15 to 35°C)
Storage temperature
From –4 to 158°F (–20 to 70°C)
Humidity range
0–85% relative humidity (RH)
Thinner section for
cut-out
Output signals
(jumper selectable)
4–20 mA, 0–20 mA, 0–10 Vdc
Resolution of analog
outputs
10 ppm CO
2
Recommended external
load
Current output: max. 500
Ω
Voltage output: min. 1000
Ω
Power supply
Nominal 24 Vac
Power consumption
< 5 VA
Warm-up time
< 15 minutes
Housing material
ABS plastic
Mounting holes
For standard Asian, European,
and North American junction
boxes
Dimensions
4
1
/
4
in. × 3
1
/
8
in. × 1
7
/
16
in.
(108 mm × 80 mm × 36 mm)
Table 1:
Sensor specifications (Continued)
