119/166
Siemens Building Technologies
Basic Documentation RVA47.320
CE1P2379E
HVAC Products
Description of the OEM settings
15.07.2002
5.10
Overtemperature protection for the pump
heating circuit
•
Prevents overtemperatures in the pump heating circuit
•
Enhances the control performance of a 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.
1.
Press the line selection buttons to select operating line 34OEM.
2.
Press the + / - buttons to activate or deactivate the overtemperature protection.
Setting range
Unit
Factory setting
0 / 1
-
1
The pump of the pump heating circuit will cycle in a way that the effect of too high flow
temperatures will be offset.
0
Overtemperature protection deactivated
1
Overtemperature protection activated
The cycling period is fixed at 10 min. This period of time will be broken down according
to the following on time ratio:
TRw
TVxGed
TRw
TVwGef
−
−
=
ε
ε
On time ratio
TVwGef Demanded flow temperature setpoint
TRw
Current room temperature setpoint
TVxGed Actual value of the attenuated flow temperature
TVKx
Actual value of cascade flow temperature (B10)
In the case of a single boiler plant without a cascade flow temperature sensor (B10),
the boiler temperature is used in place of the actual value of the cascade flow
temperature (TVKx).
Multiplication of the on time ratio by the cycling period (10 minutes) gives the number of
minutes for which the pump runs.
This means that with an on time ratio
ε
of 0.6, the pump runs for 6 minutes and is then
switched off for the remaining 4 minutes of the cycling period.
Benefit
Description
Setting
Effect
On time ratio
Note
Running time