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Siemens Building Technologies Basic Documentation RVD110, RVD130 CE1P2381E
HVAC Products 4 Acquisition of the measured values 27.05.2004
• Plants with no room temperature sensor:
The controller operates with a fixed outside temperature of 0 °C
A fault status message will be generated only when there is no actual room tempera-
ture value available.
This is the case when no room unit is used or when the room temperature measuring
circuit is faulty:
• The controller’s LCD displays Er
• When interrogating the outside temperature on the QAW70 room unit – if present –
its display will show --- if there is a short-circuit or open-circuit
4.4 Room temperature (A6)
4.4.1 Types of sensors
The room temperature is acquired via a PPS (point-to-point interface). Only a unit with
an appropriate output signal can be connected to it. The following types of units can be
used:
• Room unit QAW50
• Room unit QAW70
• Room temperature sensor QAA10
4.4.2 Handling faults
A short-circuit in the measuring circuit leads to a fault status message.
An open-circuit in the measuring circuit does not lead to a fault status message since it
is not possible to have a room unit connected.
4.4.3 Room model
The RVD110 / RVD130 feature a room model which is integrated in the controller. It
simulates the room temperature based on the progression of the outside temperature
and the type of building construction, using a defined attenuation. In plants with no
room temperature measurement, it can perform certain room functions.
4.5 D.h.w. temperature (B3 or B71)
4.5.1 Types of sensors
The required types of sensors depend on the type of plant:
• Plant types no. 2...8 (sensor input B3):
Suitable are:
− All Siemens sensors using a sensing element LG-Ni 1000 Ω at 0 °C. Suited are
the strap-on temperature sensor QAD22 and the immersion temperature sensor
QAE22 with a range of use of 0...130 °C
− Commercially available sensors using a sensing element Pt 500 Ω with a range of
0...140 °C
The controller is able to automatically identify the type of sensor used.
• Storage tank with plant types no. 6 and 7 (sensor input B71):
− Suited are all Siemens sensors using a sensing element LG-Ni 1000 Ω at 0 °C
− The d.h.w. temperature in the storage tank can also be acquired with a control
thermostat
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