Setting protective functions
40
This function protects the system against overheating in the following situations:
•
If no hot water is used over an extended period of time (e. g. during a vacation)
•
If the collector protection temperature is exceeded
If the temperature in the collector falls below the temperature in the storage tank (usually
at night), the solar circuit pump switches on. This recools the storage tank to a preset
temperature.
For this function you can set the following parameters:
•
Basic settings/Solar circuit/Collector protection
•
Basic settings/Solar circuit/Recooling
4.7
Setting the "Drain-back" function
The "Drain-back" function can be activated only if the "Recooling" function has
been deactivated.
With drain-back systems, the collector will be drained empty when the pump is off. To
pump the air out of the system, the pump will be operated at 100 % for an adjustable
time.
The "Min runtime" parameter is used to set a minimum pump runtime.
The "Condition time" parameter is used to set how long the conditions for switching on
and off must be active in order to take effect.
The fill time and the minimum runtime are reduced in the case of short switch-off times.
For this function you can set the following parameters:
•
Basic settings/Solar circuit/Drain-back
•
Basic settings/Solar circuit/Drain-back/Fill time
•
Basic settings/Solar circuit/Drain-back/Min runtime
•
Basic settings/Solar circuit/Drain-back/Condition time
You can choose between the control types "Temperature difference" and "Radiation-
controlled".
Temperature difference
In the case of the "Temperature difference" charging principle, the solar circuit pump is
controlled in such a way that the temperature difference between the collector and the
storage tank is maintained at as constant a level as possible.
Radiation-controlled
When the level of radiation reaches the preset radiation value, the solar circuit pump is
switched on for the duration of the preset pump runtime.
