Handling Faults; Storage Tank Temperature (B31); Measuring Variable; Types Of Sensors - Siemens RVD230 Basic Documentation

26/130
Siemens Building Technologies
HVAC Products
All types of sensors from Siemens with a sensing element LG-Ni 1000. Suited for
−
d.h.w. applications is the immersion temperature sensor QAE2... Its range of use
is 0...130 °C
Commercially available sensors using a sensing element Pt 500 Its sensing range
−
is 0...180 °C
The controller automatically identifies the type of sensor used.
• Sensor input B12:
All types of sensors from Siemens with a sensing element LG-Ni 1000. Suited for
−
d.h.w. applications is the immersion temperature sensor QAE2...
4.5.3

Handling faults

Fault handling depends on the type of plant:
• Plant types using 1 d.h.w. flow sensor (B3):
If there is a malfunction (short-circuit or open-circuit), an error message will be gener-
ated
• Plant types using 2 d.h.w. flow sensors (B3 and B12):
In the event of a short-circuit or open-circuit, the controller first attempts to use the
second sensor. Only a short-circuit leads to an error message
• 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 diverting valve will be deactivated or fully closed
• 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

Measuring 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
second sensor. If no second sensor is available, an error message will be generated.
Basic Documentation RVD230
4 Acquisition of measured values
CE1P2383en
27.05.2004