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Siemens Building Technologies
Basic Documentation RVA63.242, RVA53.242
CE1P2373E
Landis & Staefa Division
Description of OEM settings
26.03.2001
5.28 Overtemperature protection for the pump
heating circuit
No overtemperatures in the pump heating circuit.
The flow temperature can be higher than that called for by the pump heating circuit
(e.g. in the case of a higher setpoint demand by another consumer). The controller
offsets the surplus energy by letting the pump cycle, thus preventing the pump heating
circuit from overheating.
Setting range
Unit
Factory setting
0 / 1
–
1
This setting switches overtemperature protection on or off:
0
Inactive:
The heating circuit pump is operated without overtemperature protection.
1
Active:
Overtemperature protection operates the heating circuit pump in a way that
excessive flow temperatures will be compensated.
When overtemperature protection is provided, the heating circuit pump cycles, thus
reducing excessive flow temperatures that lie above the setpoint. The cycling period is
fixed at 10 minutes.
ε
=
−
−
TVwGef
TRw
TKxGed
TRw
ε
On time ratio
TVwGef
Demanded flow temperature setpoint
TRw
Current room temperature setpoint
TKxGed
Attenuated boiler temperature
TKx
Actual value of the common flow
temperature
The pump’s running time is set to a minimum of 3 minutes.
The pump’s off time is set to a minimum of 2 minutes.
Also, the pump will be activated and deactivated at the following switching points:
Pump continuously ON
TVxGed
≤
TVwGef (
ε
≥
1)
Pump continuously OFF
T
K x
≤
T
R w
If a flow sensor is connected (mixing heating circuit), overtemperature protection for the
heating circuit pump is inactive.
Benefit
Description
Setting
Effect
Protection against
overtemperatures
On time ratio
Limitations
Notes