282/348
Siemens Building Technologies
Basic Documentation RVP540 / RVP550
CE1P2488en
HVAC Products
Description of the EXP settings
18.10.2002
5.6 Release integral of burner stage 2
•
Optimum switching on of burner stage 2
Setting of the heat deficit for releasing burner stage 2.
Setting range
Unit
Factory setting
0...500 K*min 50
The setting changes the switch-on behavior of burner stage 2.
Entry:
Increase:
Burner stage 2 will be released when the heat deficit is greater
Decrease:
Burner stage 2 will be released when the heat deficit is smaller
If, with burner stage 1, the boiler temperature falls below the switch-off setpoint (TKw -
SDK/2) by the amount of the release limit set here, the controller will release the sec-
ond burner stage.
During the time burner stage 2 is released, the controller will activate and deactivate
burner stage 2 according to the switching differential.
The temperature-time integral is a continuous summation of the temperature
differential over time. In this case, the decisive criterion is the difference by which the
boiler temperature falls below the burner’s switch-on setpoint (TKw-SDK/2-TKx).
Through the generation of the temperature-time integral it is not only the period of time
that is considered, but also the extent of the undershoot. This means that when the
crossing is significant, burner stage 2 will be released earlier.
When the release integral (area "a“ in the diagram below) has reached the value set,
burner stage 2 will be released.
50
48
52
TKx
23
71
Z
32
°C
44
46
t
TKw+SDK/2
a
TKw
TKw-SDK/2
tF
a Release
limit
TKw
Boiler temperature setpoint
TKx
Actual value of the boiler temperature
SDK
Switching differential of the boiler
t Time
tF
Time of release
Benefit
Description
Setting
Effect
Burner stage 2
Note
Temperature-time
integral
Switching point
Example