Data Sheet for Product

Shorting plug in the mid position (R2) = 0...50 °C (factory setting)
Shorting plug in the lower position (R3) = − 50...+ 50 °C
• For activating the test function:
Shorting plug in the vertical position: The values according to the table "Test function
active" will be made available at the signal output.
In the event of fault, the output signal will reach 0 V (4 mA) after 60 seconds.
Engineering notes
Room sensors with active outputs have a high power loss, which ultimately influences
temperature measurement. The degree of influence depends on the operating voltage
and is compensated in the Symaro
TM
room sensors for an operating voltage of AC 24 V
or DC 24 V. Over- or undercompensation may occur for other operating voltages.
Furthermore, the measuring accuracy is impacted by the following factors:
- Prevailing air flow
- Wall surface (rough, smooth)
- Wall texture (wood, plaster, concrete, brick)
- Wall type (interior, exterior).
This application-specific measuring inaccuracy is constant for an installed sensor after
approx. 1 operating hour, and it can be adjusted as needed in a higher system (e.g.
controller).
No correction on the local LCD.
To power the sensor, a transformer for safety extra low-voltage (SELV) with separate
windings for 100 % duty is required. When sizing and electrically protecting the trans-
former, local safety regulations must be observed.
When sizing the transformer, the power consumption of the room temperature sensor
must be taken into consideration. For correct wiring, refer to the Data Sheets of the
devices with which the sensor is used.
The permissible cable lengths must be observed.
When laying the cables, it must be observed that the longer the cables run side by side
and the smaller the distance between them, the greater the electrical interference.
Twisted pair cables are required for the secondary supply lines and the signal lines.
Mounting notes
On an inner wall of the space to be heated or air conditioned. Not in recesses, shelves,
not behind curtains, not above or near heat sources.
The unit must not be exposed to direct solar radiation.
The end of the conduit at the sensor must be sealed to prevent false measurements
due to draughts through the conduit.
The permissible ambient conditions should be observed.
Installation instructions are printed inside of the packing.
Commissioning notes
Check wiring before switching on power. The temperature measuring range must be
selected on the sensor, if required.
Fault
Cable routing and
cable selection
Location
Installation instructions
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Siemens Room temperature sensors QAA20..1.. CE1N1749en
Building Technologies 2014-07-30