Quick Setback With Room Sensor; Overtemperature Protection Mixing Heating Circuit - Siemens RVA63.242 User Manual

Benefit
Description
Important
Process
Effect
Note
Description
Note
Process
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Siemens Building Technologies
Landis & Staefa Division

6.5 Quick setback with room sensor

Making use of the building's thermal storage capacity.
Quick setback is dependent on whether or not a room temperature sensor is used. A
differentiation must therefore be made between quick setback with or without room
sensor.
This process has an impact only when a room sensor is used.
Quick setback is started as soon as a change to a lower room temperature setpoint
takes place (e.g. switching times in automatic mode).
Quick setback is terminated as soon as the actual room temperature reaches the level
of the respective room temperature setpoint (TRx = TRw).
°C
20
15
TRw
H
ON
OFF
TRx Actual value of the room temperature
TRw Room temperature setpoint
H Quick setback function
Due to the readjustment of the room temperature setpoint, the heating circuit pump will
be switched off until the quick setback process is terminated. This means that the room
temperature falls quicker since the supply of heat from the boiler is cut off.
If no room sensor is connected, quick setback will not be accomplished through this
process. Also refer to "constant for quick setback" in Index.
6.6 Overtemperature protection mixing heating
circuit
This function is used to prevent the mixing heating circuit from reaching excessive
temperatures, caused by a defect of the mixing valve, for example.
The function is independent of the pump heating circuit's overtemperature protection
and cannot be deactivated.
If the flow temperature exceeds the limit value "Maximum limitation of flow temperature"
+ 7.5 °C (fixed value), the pump will be deactivated.
This limit function acts only with the mixing heating circuit.
Basic Documentation RVA63.242, RVA53.242
General control processes
TRx
t
t
CE1P2373E
26.03.2001