Setpoint Rise; 3-Position Control - Siemens RVL481 Basic Documentation

Function
Effect on d.h.w. heating
48/118
Siemens
Building Technologies

11.2.2 Setpoint rise

T
Vw
t
t Time
∆t
Unit of time
TVw Flow temperature setpoint
∆TVw
Rate of setpoint increase per unit of time
The rate of increase of the flow temperature setpoint can be limited to a maximum. In
that case, the maximum rate of increase of the flow temperature setpoint is the selected
temperature per unit of time (°C per hour). This function:
• prevents cracking noises in the piping
• protects objects and construction materials that are sensitive to quick temperature
increases (e.g. antiquities)
• prevents excessive loads on heat generating equipment
This function can be deactivated (setting --- ).
During d.h.w. heating, limitation of the rate of increase acts as follows:
Plant type Effect
1–x
3–0
3–2
3–4 Limitation of the rate of increase is always active
3–5
4–x
6–x
3–1 Limitation of the rate of increase only acts with shifting or
3–3 parallel d.h.w. priority
11.3

3-position control

3-position control operates as weather- or demand-compensated PI flow temperature
control. The flow temperature is controlled through a modulating actuating device (slip-
per or seat valve). Owing to the I-part, there is no control offset.
The controller's positioning commands to the actuator of the actuating device are fed to
the output relays and indicated by LEDs.
Heating and D.h.w. Controller RVL481
11 Function block "3-position actuator heating circuit"
T
Maximum rise: =
Vw
t
∆T
Vw
∆t
CE1P2541en
20.05.2008