Siemens RVD240 - Handling Faults; Storage Tank Temperature (B31); Measured Variable; Types of Sensors

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Siemens Building Technologies Basic documentation RVD240 CE1P2384en
HVAC Products 4 Acquisition of measured values 27.05.2004
• Commercially available sensors using a sensing element Pt 500. Its range of use is
0...180 °C
The controller automatically identifies the type of sensor used.
4.5.3 Handling faults
If there is a malfunction (short-circuit or open-circuit), an error message will be deliv-
ered.
In the event of fault, the plant responds as follows, depending on the type of d.h.w.
actuating device used:
• The d.h.w. intermediate circuit pump will be deactivated
• The mixing valve will be fully closed
• If pump charging is in progress, it will be stopped by deactivating the storage tank
charging pump
When querying the d.h.w. temperature on the QAW70 room unit (if present), its display
shows --- in both cases, if there is a short-circuit or open-circuit.
4.6 D.h.w. storage tank temperature (B31)
4.6.1 Measured variable
The storage tank temperature is always acquired at input B31. Depending on the type
of plant, it is possible to use a second storage tank sensor (B32).
4.6.2 Types of sensors
The type of sensor is the QAE22... immersion sensor with a sensing element LG-
Ni 1000.
Thermostats cannot be used.
4.6.3 Handling faults
In the event of a short-circuit or open-circuit, the controller first attempts to use the sec-
ond sensor. If no second sensor is available, an error message will be delivered
4.7 D.h.w. storage tank or return temperature
(B32)
4.7.1 Measured variable
Depending on the type of plant, input B32 is used for acquiring the
• secondary return temperature in the d.h.w. circuit (plant types x–4)
• storage tank temperature (other plant types)
4.7.2 Types of sensors
The type of sensor is the QAE22... immersion sensor with a sensing element LG-
Ni 1000.
Thermostats cannot be used.