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Siemens
Heating controllers RVP201 and RVP211
CE1P2464en
Building Technologies
3 Technical design
2017-07-21
This means that the minimum burner running time has priority. To be considered is the
boiler temperature's maximum limitation however, which always switches the burner off.)
T
Kw
+ 0,5 × SD
0
1
25
22
D
1
4
T
K
T
Kw
T
Kw
- 0,5 × SD
T
Kx
t
Y
B
SD Switching
differential
t
Time
T
K
Boiler
temperature
w
TK
Boiler temperature setpoint
x
TK
Boiler temperature actual value
Y
B
Burner control signal
Frost protection for the boiler uses fixed values:
Switch-on point: 5 °C boiler temperature (= minimum limit value)
Switch-off point: minimum limit value of boiler tempe switching differential.
For the switching differential, the value set for control will be adopted
During quick setback or when there is no demand for heat, the boiler will be shut down,
that is, no defined minimum temperature will be maintained.
If, however, the boiler temperature falls below 5 °C, the burner will always be switched
on until the boiler temperature has exceeded the minimum limit value of the boiler tem-
perature by the amount of the switching differential. This always ensures a minimum
boiler temperature of 5 °C.
3.3.8 Limitations
The maximum limitations are no safety functions! For this purpose, devices such as
thermostats, limit thermostats, etc., are to be used.
Maximum limitation of the flow temperature can be set in the range 10…100 °C.
At the limit value, the heating curve runs horizontal. This means that the flow tempera-
ture setpoint cannot exceed the maximum value.
This function can be disabled.
Maximum limitation of the boiler temperature can be set in the range 10…100 °C.
The burner's switch-off point cannot be higher than the maximum limit value. In that
case, the switch-on point will be lower by the amount of the set switching differential.
This function can be disabled.
Frost protection for the
boiler
Note
Maximum limitation of
flow temperature
Maximum limitation of
boiler temperature
