Viessmann Vitocal 222-G User Manual page 117

Vitocal 300-G/350-G
4.10 Vitocal 300-G/350-G, two-stage, one heating circuit without mixer, two heating cir-
cuits with mixer, DHW heating, heating water buffer cylinder
ID: 4605440_1304_03
Application range
Large luxurious detached houses, apartment buildings and buildings
for commercial use with three heating circuits with different design
layouts. Size DHW cylinder eP in accordance with current standards
and requirements.
Main components
■ Vitocal 350-G, type BW (7.3 kW)
■ Vitocal 300-G, type BWS (up to 17 kW)
■ Vitotronic 200, type WO1B
■ Heating circuit distributor with one heating circuit without mixer and
two heating circuits with mixer
4
■ DHW cylinder
■ Heating water buffer cylinder
Heating water buffer cylinder
The minimum flow rate of heat pump stages 1/9 is safeguarded via
heating water buffer cylinder zP and secondary pumps 6/qP. It is
possible to use differential pressure-dependent heating circuit pumps
uZ and oZ.
Central heating by heat pump
Stage 1 1, primary pump 5 and secondary pump 6 start when the
actual temperature captured by cylinder temperature sensor zQ of
heating water buffer cylinder zP falls below the set temperature selec-
ted at control unit 2.
Required parameter settings
ID: 4605440_1304_03
Parameter
7000
5030
5130
VIESMANN
122
(cont.)
Value Function
10 With heating circuit A1/HC1, M2/HC2, M3/HC3, DHW cylinder
according to type plate Rated heating output, heat pump stage 1
according to type plate Rated heating output, heat pump stage 2
If the output of stage 1 is insufficient, i.e. the integral derived from the
duration and amount of the deviation between the set and actual val-
ues of the flow temperature exceeds the value specified at control unit
2, then stage 2 9 plus primary pump wT and secondary pump qP
are also started to raise the heating output.
Control unit 2 regulates the heating water flow temperature. Subject
to demand, secondary pumps 6/qP deliver heating water to the heat-
ing water buffer cylinder, or via circulation pump for cylinder heating
7 to DHW cylinder eP.
Heating circuit pumps uZ and oZ deliver the required water volume to
the heating circuits. The flow rate in the heating circuit is regulated by
opening or closing the thermostatic radiator valves or the valves of the
underfloor heating distributor.
To balance the difference in water volume between the primary and
secondary circuits, operate heating water buffer cylinder zP in parallel
to the heating circuits. Any heat not absorbed by the heating circuits
is stored in heating water buffer cylinder zP. In addition, heat pump
1 achieves longer runtimes, and the heating circuits are supplied with
heat from heating water buffer cylinder zP during power-OFF peri-
ods.
Both stages 1/9 of the heat pump will restart when the temperature
at temperature sensor zQ in heating water buffer cylinder zP falls
below the set value.
DHW heating by heat pump
In the delivered condition, DHW heating through stage 1 1 takes pri-
ority over the heating circuits.
The heat demand is issued via cylinder temperature sensor eW and
control unit 2, which controls circulation pump for cylinder heating
7. The control unit raises the flow temperature to the value required
for DHW heating.
System examples