Basic Documentation

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Siemens Modular Heating Controller RMH760B CE1P3133en
Building Technologies 9 Heating circuit control 2017-09-29
Rule of thumb for calculating the lift at the inflection point:
Lift ≈
(Flow temperature setpoint
at nH = 1
– 20 °C)
×
(nH – 1)
Lift
≈
(32 °C – 20 °C)
×
(1.5 – 1)
= 6 K
Main menu > Heating circuit 1 (or 2 or 3) > Heating curve
Operating line
Range
Factory setting
[Curvepoint 1] outside temp
–50…10 °C
–11 °C
[Curvepoint 1] flow temp
25…140 °C
60 °C
[Curvepoint 2] outside temp
5…30 °C
15 °C
[Curvepoint 2] flow temp
5…140 °C
30 °C
Radiator exponent
1.00…2.00
1.30
• The heating curve is identical to that of the DESIGO system
• Setting of the radiator exponent can be derived from the type of heating system and
is based on physical ground
9.5.3 Influences on the flow temperature setpoint
The basis used for the flow temperature setpoint is the heating curve. In addition, the
setpoint is influenced by the following variables:
• Room temperature setpoints
• Room temperature
• Boost heating (refer to subsection 9.7.3 "Quick setback and boost heating")
The basic heating curve applies to a room temperature setpoint of 20 °C. A positive
room temperature setpoint change
∆TR corresponds to a displacement of the heating
curve by the same amount toward the outside temperature and to a displacement by
the same amount toward the flow temperature.
3131B21
TFl
TOeff
+
-
SpTR
20 °C
SpTFlDe
SpTFlHi
SpTRN
TFl
TOeff
TODe TOHi
+
-
+
+
SpTR
Roughly, this corresponds to the value of:
∆TFl = ∆TRw × (sHc + 1)
sHc =
SpTFlDe – SpTFlHi
ToHi – ToDe
Setpoint readjustment ∆TRw = 2 K. ∆TFl = ?
sHc =
60 – 30
= 1.5
⇒
∆TFl = 2 K × (1,5 + 1) = 5 K
(15– [–5 ])
A deviation of the actual room temperature from the room temperature setpoint has an
impact on the flow temperature setpoint only when room temperature influence is
activated.
Rule of thumb:
Example above:
Heating curve
Notes
Impact of the room
temperature setpoint
Example
Impact of the room
temperature