Sonnenkraft HKM20 Manual página 31

Constant pressure control
This control type maintains a constant differential pres-
sure over the pump independent of the flow rate. The
constant pressure curves are indicated by CP1 and CP2 in
the Q/H diagram. These run horizontally in the diagram.
Automatic night setback
Warning: Pumps which are installed in heat generators
that only exhibit a low water content must never be set
to the automatic night setback mode (please contact your
specialist dealer if necessary).
Note:
The automatic night setback function is deactivated if the
pump is set to speed level I, II or III. If the heating sys-
tem is providing the heating elements with insufficient
heat, check whether the automatic night setback function
has been activated. Deactivate the automatic night set-
back function if necessary. In order to ensure correct
operation of the automatic night setback function the
following conditions must be fulfilled:
• The pump must be installed in the flow pipe
• The heat generator must be equipped with an automatic
flow temperature controller The button must be pressed
to activate the automatic night setback function (see
‚Button for activating automatic night setback').
Functionality of the automatic night setback mode
If the automatic night setback mode is activated the
pump will automatically switch between normal operation
and night setback. Switching between normal operation
and night setback is dependent on the flow temperature.
The pump automatically switches to night setback if the
flow temperature drops by more than 10-15°C within
approx. two hours. The temperature drop must be at
least 0.1°C/min.
The pump switches to normal operation as soon as the
flow temperature has increased again by 10°C.
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