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Siemens
Heating and D.h.w. Controller RVL481
CE1P2541en
Building Technologies
11 Function block "3-position actuator heating circuit"
20.05.2008
11.2.2 Setpoint
rise
t
t
25
4
0
D
0
7
T
Vw
T
Vw
Maximum 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
3–5
4–x
6–x
Limitation of the rate of increase is always active
3–1
3–3
Limitation of the rate of increase only acts with shifting or
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.
Function
Effect on d.h.w. heating
