Gebwell Qi 10, Installation, Operation And Maintenance Manual

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36 v3-8 23052017
2840 Return temperature switching difference
OFF Switching off point
ON Switching on point
TRLw Return water temperature set point
K Compressor
Once the return water temperature rises above set point by
a half of switching differential, the compressor comes to a
halt. Once the return water temperature drops below the
set point by a half of switching differential, the controller
will turn on the compressor.
If return water temperature drops below 30°C, the
switching differential is reduced so that switching on point
comes closer to set point. Return water set point being
20°C the switching on point is the same as return water set
point.
2840 Return temperature switching difference
TRLw Return water temperature set point
T Heat pump return water temperature
OFF Switching off point
ON Switching on point
Ta Outdoor temperature
11.7 Settings for the electric resistor (SV1)
The electrical resistor of the heat pump operates in 2
phases according to factory settings. 2-phase resistance
means that two resistors with different power operate at
different times. If more resistor power is needed, the
power can be increased to 3-phase. The fuses of the
building and the heat pump must be selected according to
the heat pump’s maximum current. The maximum
currents are given in the technical information section of
the manual. In the event of failure, the heat pump uses an
electrical resistor as well as in partial ground source
heating systems alongside a compressor.
Resistor phase 1: 3 kW
Resistor phase 2: 6 kW
Resistor phase 3: 9 kW (requires a change in settings)
11.8 Electric resistor’s operating method
(SV1)
Set in factory settings, the electrical resistor (SV1)
operates alongside the compressor in heating and
producing domestic water. This means that if the
compressor cannot generate enough power to heat
domestic water for the building, the electrical resistor will
be turned on automatically.
The electrical resistor is turned on and off depending on
the temperature and set value of the return water. If the
return water temperature is lower than the set value by one
half of the switching differential (factory setting for the
switching differential: 6 degrees), the controller will start
to count down the prevention time for releasing the
electrical resistor. When the prevention time has ended,
the controller will calculate the heat deficit by degree
minutes. When the degree minute time has ended, the
controller will switch on the first resistor phase. After this,
the controller will start to count the heat deficit again if
the resistor has not raised the return water temperature up
to the range between the switching differential. If the
release time expires, resistor phase 1 (3 kW) will turn off
and resistor phase 2 (6 kW) will turn on. When the return
water reaches the switching differential range (set value
+- ½ of the switching differential), the controller will turn
off the electrical resistors.
The settings for starting the electrical resistor can be
changed via the menu
Heat pump > Control rows 2881-
2884.
Settings are defined at the
“Expert”
-level.