Data Sheet for Product

Technical Instructions QPA20xx Series Indoor Air Quality Room Sensors
Document Number CE1N1961
July 26, 2019
Page 6 Siemens Industry, Inc.
Cable Routing and
Selection
• When laying the cables, it should be considered that electrical interference increases
the longer the cables run parallel and the smaller the distance between them.
• On applications with EMC problems, shielded cables should be used.
• For the secondary power lines and signal lines, use cables with twisted pairs.
Mounting Notes
• Inner wall of the room to be ventilated, not in niches, behind curtains, above or near
heat sources, and not exposed to direct light from spot lights.
• Do not expose the sensor to direct sunlight.
• Airflow of greater than 30 fpm may affect the temperature and humidity sensing
accuracy. Avoid installing in areas prone to drafts.
• The end of the conduit at the sensor must be sealed to prevent inaccurate
measurements due to drafts through the conduit.
• Installation Instructions are included with the unit.
Commissioning
Notes
Check the sensor’s functions can be checked 30 minutes after applying power.
• Checking the CO
2
function:
In well-ventilated rooms, the sensor shows the CO
2
concentration of the outside air.
Typically, this is 360 ppm (depending on the sensor’s measuring accuracy). Also, a
basic functional check can be made by exhaling on the sensor. Note that the sensor’s
rate of response has been purposely delayed (time constant t
90
= 5 minutes).
• Checking the VOC function:
Touch the sensor with a cotton ball dowsed in alcohol.
• Ventilation should start when the preset switching level of the connected controller is
reached.
• After applying power to sensors with display, “In it” will appear for about six seconds.
Specifications
Power supply
Operating voltage (SELV) 24 Vac 20%, or 15 to 35 Vdc
Frequency 50/60 Hz at 24 Vac
Power consumption 2 VA
Cable length for
measuring signal
Permissible cable length See the Technical Instructions of the
device handling the signal
Functional data, CO
2
Measuring range (MW = measured value) 0 to 2000 parts per million (ppm)
Measuring accuracy @ 73°F (23°C) < + (50 ppm + 2% measured value) *
and 1013 hPa
Temperature dependency in 41°F to 113°F + 2 ppm/°C
typically (5°C to 45°C) range
Long-time drift < + 5% measuring range/5 years
Time constant t
90
<5 minutes
Output signal, linear (terminal X1) 0 to 2000 ppm
Recalibration Not required for 8 years
*Allow up to 96 hours for unit to reach published accuracy.
Functional data,
maximum selection of
CO
2
and VOC with
QPA2002 and QPA2002D
Measuring range 0 to 2000 ppm
VOC sensitivity See Table 1
Output signal, linear (terminal X2) 0 to 2000 ppm
Response time, VOC signal t
voc
3 minutes/V