Wilo Stratos Notice De Montage Et De Mise En Service page 14

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6.2.2 Differential-pressure control systems
The control systems which can be selected are:
• Δp-v: (Factory default setting) The electronics increase the pump's differential
pressure set point in a straight line between ½ Hs and Hs. The differential
pressure set point Hs increases or decreases in accordance with the required
flow rate (fig. 7).
• Δp-c: The electronics keep the differential pressure generated by the pump at
a constant differential pressure set point Hs over the entire operation range of
the pump (fig. 8).
• Δp-T: The electronics alter the nominal differential pressure set point
dependent on the fluid temperature measured. This control system can only be
adjusted with an IR operating and service unit (accessory) or by serial digital
interface. There are two possible settings (fig. 9):
• Positive control: As the system temperature rises, the nominal differential
pressure set point is increased linearly between Hs
IR-module/IR-stick: Hs
Used i.e. with standard boilers with sliding flow temperature.
• Negative control: As the system temperature rises, the nominal differential
pressure set point is decreased linearly between Hs
IR-module/IR-stick: Hs
Used i.e. with condensing boilers where a specific minimum return water
temperature must be maintained to achieve as much condensing as possible
to insure maxium boiler effeciency. To do this, the pump must be installed in
the system's return.
6.2.3 Other energy-saving operating modes
• Speed regulation mode operation: The speed of the pump is kept at an
externally set constant speed between minimum and maximum speeds (fig. 10).
The speed regulation mode deactivates the differential pressure control.
• In the "auto" operating mode the pump is able to recognize a minimum system
heat output requirement due to a sustained drop in the system temperature and
then automitically switch to night setback mode. If the heat output
requirement rises, the pump automatically switches to standard mode. This
setting ensures that the pump's energy consumption is reduced to a minimum
and in most cases is the optimum setting.
CAUTION! Possible damage of the pump!
Setback mode may only be enabled when the system is hydraulically
balanced. Inadequately supplied system parts may otherwise freeze in the
event of frost.
6.2.4 General pump functions
• The pumps are fitted with an electronic overload protection system which
switches the pump off should it become overloaded.
• The control module is equipped with a non-volatile memory for data storage.
What this means is that data is saved, even during long periods of down time.
10
> Hs ).
max min
< Hs ).
max min
Subject to technical alterations!
and Hs (setting on
min max
and Hs (setting on
min max
WILO SE 03/2016