Cooling The Heating Water/Coolant Buffer Cylinder - Viessmann VITOTRONIC 200 Service Instructions Manual

Function description
Photovoltaics
(cont.)
Note
Central heating continues if, whilst the interior is being
heated, the conditions for utilisation of power gener-
ated on site are no longer met (see "Enabling utilisa-
tion of power generated on site"). The heat pump and
any booster heaters required are supplied with power
from the grid . The raising of the set temperature is
no longer taken into account.

Cooling the heating water/coolant buffer cylinder

If the electrical output of the photovoltaic system
exceeds the "Threshold for electrical power 7E04",
the set buffer temperature will be reduced by the
"Reduce set coolant buffer cylinder temperature
PV 7E26", provided that the "Min. temperature cool-
ant buffer cylinder 722A" is not undershot in the
process.
In order to cool the heating water/coolant buffer cylin-
der to the reduced set buffer temperature the following
conditions must be met:
Utilisation of power generated on site is enabled:
■
See "Enabling utilisation of power generated on site".
■ The buffer temperature exceeds the reduced set buf-
fer temperature.
■ A cooling demand for the heating/cooling circuits is
expected soon. For this forecast, the outside temper-
ature curve for the previous day is evaluated.
In "Time prog buffer cyl" time phase 1 is active for
■
the next 5 h.
Central cooling
"Standard room temperature 2000" is reduced by
"Reduce set room temperature PV 7E25".
Central cooling begins if all of the following conditions
are met:
■ Utilisation of power generated on site is enabled:
See "Enabling utilisation of power generated on site".
■ There is a cooling demand.
■ In "Time proghtg/cooling" one time phase is
active.
72
Utilisation of power generated on site for cooling the
heating water/coolant buffer cylinder ends when the
reduced set buffer temperature is reached at the sec-
ondary circuit return temperature sensor.
Note
The reduced set buffer temperature becomes inactive
if, whilst the heating water/coolant buffer cylinder is
being cooled, the conditions for utilisation of power
generated on site are no longer met (see "Enabling uti-
lisation of power generated on site"). Cooling contin-
ues until the standard set buffer temperature has been
reached. To achieve this, the heat pump is supplied
with power from the grid.
Central cooling with utilisation of power generated on
site stops when there no longer is a cooling demand.
Note
Central cooling continues if, whilst the interior is being
cooled, the conditions for utilisation of power gener-
ated on site are no longer met (see "Enabling utilisa-
tion of power generated on site"). The heat pump is
supplied with power from the grid. The lowering of
the set temperature is no longer taken into account.