Rotex Controller Series, Product Documentation

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EbV Product documentation THETA NORM/UNIT
7-4
NOTE: The HEATING LIMIT parameter can be used to assist the summer switch-off function
during the transitional seasons (see selection levels unmixed circuit, mixed circuit 1 or
mixed circuit 2 - Parameter 7). This function allows setting non-heating periods on warm
days during the transitional seasons for each individual heating circuit.
NOTE: In connection with a 2nd external sensor, the current average outside temperature is
applied for the summer switch-off as long as the mean value of both sensors was
determined when assigning the external sensors.
When the summer switch-off mode is active, it is indicated on the basic display by a
sunshade symbol. In case of separate operation of the heating circuits ("Operating
mode" system parameter), the symbol is not displayed. If two outdoor sensors are
connected and these are assigned to different heating circuits, the symbol is only
displayed if both sensors fulfil the conditions for summer switch-off.
7.4 System Frost Protection
Function: To keep the heating system from freezing in switch-off mode, the controller is equipped
with electronic frost protection.
Operation without Room Temperature Measurement
If the outside temperature (current value) drops below the set limit, the heating is turned
on again. The heating is interrupted if the outside temperature exceeds the set limit by
1 K.
Operation with Room Temperature Measurement
If the room temperature is above the room setpoint, the heating circuit pumps only
activate at outside temperatures below the set freezing limit.
If the room temperature drops below the set room setpoint, the heating operation is re-
sumed.
The heating is switched off again if the room temperature exceeds the set room setpoint
by 1 K. If, at this moment, the outside temperature is still below the set freezing limit,
only the heating circuit pumps remain active.
NOTE: If not every heating circuit is operated with room temperature measurement, different
frost protection functions can be assigned to the individual heating circuits. If, for
example, a mixed circuit is operated with room temperature measurement and the boiler
heating circuit is not, the latterís heating curve and room temperature setpoint are to be
set as low as possible.
In connection with a 2nd outdoor sensor, the frost protection function is activated, as
soon as one of the two outside temperatures drops below the frost protection limit.
In case of a faulty outdoor sensor, the frost protection is constantly activated.
Operation:
Note on operation Key / parametertree Parameter
Setting limit temperature
SYSTEM SUMMER