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Siemens Building Technologies
Basic Documentation RVD230
CE1P2383en
HVAC Products
12 Function block Space heating
27.05.2004
12
Function block Space heating
12.1 Operating
lines
Line Function, parameter
Unit
Factory
setting
Range
61
Heating limit (ECO)
K
–3
--- / –10…+10
62
Building time constant
h
20
0…50
70
Effect of the room temperature (gain factor)
10
0…20
71
Parallel displacement of the heating curve
K
0.0
–15.0…+15.0
72
Overrun time heating circuit or system pump
min
4
0…40
73
Maximum limitation of room temperature
K
---
--- / 0.5…4
74
Optimization with / without room temperature sensor
0
0 / 1
75
Maximum heating up time
h
0:00
0:00…42:00
76
Maximum early shutdown
h
0:00
0:00…6:00
77
Maximum rate of flow temperature increase
°C/h
---
--- / 1…600
78
Quick setback
1
0 / 1
12.2 Compensating
variables
12.2.1 Outside
temperature
The RVD230 makes use of 3 types of outside temperatures:
•
The actual outside temperature (T
A
)
•
The composite outside temperature (T
AM
). It is generated by filtering the actual outside
temperature by the building time constant. The proportion of the actual outside tem-
perature is 50 %.
The composite outside temperature suppresses unnecessary reactions of the control
system if the outside temperature changes for short periods of time.
In the case of the weather-compensated types of control (without or with room tem-
perature influence), the RVD230 uses the composite outside temperature.
The building time constant is a measure of the type of building construction and indi-
cates how quickly the room temperature would change if the outside temperature sud-
denly changed. The building time constant can be adjusted:
Type of building construction Recommended building time constant
Light
10 h
Medium
20 h
Heavy 50
h
•
The attenuated outside temperature (T
AD
). It is generated by filtering twice the actual
outside temperature by the building time constant. This means that, compared with the
actual outside temperature, the attenuated outside temperature is considerably damp-
ened. This ensures that no heating will take place in the summer when, under normal
circumstances, the heating would be switched on because the outside temperature
drops for a few days
If operating line 25 is selected (display of the actual room temperature) and the 2 but-
tons
and
are pressed simultaneously for about 3 seconds, the attenuated and
the composite outside temperature will generate the current measured value; the gen-
eration of these 2 variables will then start anew (outside temperature reset).
Tip
