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Siemens Building Technologies
Room sensors QFA20…
CE1N1857en
HVAC Products
06.06.2005
Commissioning notes
Check wiring before switching on power. The temperature measuring range must be
selected on the sensor, if required.
Wiring and the output signals can be checked by making use of the test function (refer
to "Mechanical design").
We recommend not to use voltmeters or ohmmeters directly at the sensing element. In
the case of the simulated passive output signals, measurements with commercially
available metres cannot be made (measuring current too small).
Technical data
Operating voltage
AC 24 V
±
20 % or DC 13.5...35 V
Frequency
50 / 60 Hz at AC 24 V
Power consumption
≤
1 VA
Perm. cable lengths
refer to Data Sheet of the device
handling the signal
Range of use
0…95 % r. h. (non-condensing)
Measuring range
0…100 % r. h.
Measuring accuracy at 23 °C and AC 24 V
0...95 % r.h.
30...70 % r.h.
±
5 %
±
3 %, typically
Temperature dependency
≤
0 . 1 % r. h. / ° C
Time constant
2 min
Perm. air velocity
20 m/s
Output signal, linear (terminal U1)
DC 0...10 V 0...100 % r. h.,
max.
±
1 mA
Range of use
−
15...+ 50 °C
Measuring range
0...50 °C /
−
35...
+
35 °C
Sensing element
NTC 10 k
Ω
Measuring accuracy at
15...35 °C
−
35...+50 °C
±
0.8 K
±
1 K
Time constant
8 min (depending on air movement
and thermal coupling to the wall)
Output signal, linear (terminal U2)
DC 0...10 V 0...50 °C /
−
35...
+
35 °C
max.
±
1 mA
Measuring range
0...50 °C
Sensing element simulated, corresponding to
QFA2020
QFA2040 (serie B or higher)
LG-Ni 1000
T1 (PTC)
Measuring accuracy at
15...35 °C
−
35...+50 °C
±
0.8 K
±
1 K
Time constant
8 min (depending on air movement
and thermal coupling to the wall)
Perm. measuring current with
QFA2020
QFA2040
1.18…3.29 mA
0.53…1.46 mA
Housing
IP 30 to IEC 529
Safety class
III to EN 60 730
Screw terminals for
1
×
2.5 mm
2
oder 2
×
1.5 mm
2
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Power supply
Cable lengths for
measuring signal
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Functional data of
humidity sensor
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Functional data of
temperature sensor with
QFA2060
Functional data of
temperature sensor with
QFA2020, QFA2040
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Degree of protection
Electrical connections