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Siemens Building Technologies
Basic Documentation RVP540 / RVP550
CE1P2488en
HVAC Products
Description of the EXP settings
18.10.2002
5.7 Reset integral of burner stage 2
•
Optimum switching off of burner stage 2
Adjustment of the amount of surplus heat for locking burner stage 2.
Setting range
Unit
Factory setting
0...500 K*min 10
The setting will change the switch-off point for burner stage 2.
Entry:
Increase:
Burner stage 2 will be locked when surplus heat is greater
Decrease:
Burner stage 2 will be locked when surplus heat is smaller
When, with burner stages 1 and 2, the switch-off setpoint (TKw + SDK/2) is exceeded
by the reset integral set here, the controller will lock burner stage 2.
When burner stage 2 is locked, the controller will activate and deactivate burner stage 1
according to the set 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 tem-
perature exceeds the burner’s switch-off setpoint (TKx - (TKw + SDK/2)).
Through the generation of the temperature-time integral it is not only the period of time
that is considered, but also the extent of overshoot. This means that when the crossing
is significant, burner stage 2 will be locked earlier.
When the reset integral (area "b“ in the diagram below) has reached the value set,
burner stage 2 will be locked.
b Reset
limit
TKw
Boiler temperature setpoint
TKx
Actual value of the boiler temperature
SDK
Switching differential of the boiler
t Time
tR
Time of reset
Benefit
Description
Setting
Effect
Burner stage 2
Note
Temperature-time
integral
Switching point
Example
50
48
52
TKx
23
71
Z
34
°C
44
46
t
TKw+SDK/2
TKw
TKw-SDK/2
tR
b
