Function Block "3-Position Actuator Heating Circuit; Operating Lines; Limitations; Flow Temperature Limitations - Siemens RVL471 Basic Documentation

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Siemens Building Technologies
HVAC Products
11 Function block "3-position actuator
heating circuit"
This function block provides 3-position control of the heating circuit. Depending on the
plant type, it acts as follows:
• Weather-compensated, on the mixing valve of a space heating system (plant type 1–x)
• Weather-compensated, on the valve in the primary return of a space heating system
with a district heat connection (plant type 3–x)
• Demand-compensated, on the mixing valve of a main flow (plant type 4–x)
• Demand-compensated, on the valve in the primary return of a main flow with district
heat connection (plant type 6–x)

11.1 Operating lines

Line Function, parameter
81 Maximum limitation of flow temperature
82 Minimum limitation of flow temperature
83 Maximum rate of flow temperature increase
84 Flow temperature boost mixing valve / heat exchanger
85 Actuator running time
86 P-band of control (Xp)
87 Integral action time of control (Tn)

11.2 Limitations

11.2.1

Flow temperature limitations

The following settings can be made:
• Maximum limitation of the flow temperature. At the limit value, the heating curve runs
horizontally. This means that the flow temperature setpoint cannot exceed the maxi-
mum value
• Minimum limitation of the flow temperature: At the limit value, the heating curve runs
horizontally. This means that the flow temperature setpoint cannot fall below the mini-
mum value (exception: with locking signals)
If the setpoint is limited, the display shows:
= for maximum limitation
= for minimum limitation
Both limitations can be deactivated (setting ---).
Minimum limitation is also active during storage tank charging, depending on the kind of
priority.
With plant types 3–1 and 3-3, where maximum limitation is not active during storage
tank charging.
Basic Documentation RVL471

11 Function block "3-position actuator heating circuit"

Unit Factory Range
setting
°C --- --- / 0...140
°C --- --- / 0...140
°C --- --- / 1...600
°C 10 0...50
s 120 30...873
°C 32.0 1...100
s 120 30...873
CE1P2524E
23.10.2002