Viessmann Vitocal 222-G User Manual page 135

Vitocal 200-S/222-S/242-S
5.4 Vitocal 200-S, type AWB, one heating circuit without mixer, one heating circuit with
mixer, DHW heating, heating water buffer cylinder and external heat source
ID: 4605169_1304_08
Application range
Detached houses with different utilisation patterns. Different sizing of
the heating circuits. Size the DHW cylinder in accordance with current
standards and requirements.
Main components
■ Vitocal 200-S, type AWB, with Vitotronic 200 control unit, type WO1C
■ Heating circuit distributor with one heating circuit without mixer and
one heating circuit with mixer (KM BUS)
■ DHW cylinder
■ Heating water buffer cylinder
■ External heat source with Vitotronic 200, types KO1B, KO2B or
KW6B
Heating water buffer cylinder
The minimum flow rate of the heat pump is safeguarded via heating
water buffer cylinder zP and secondary pump 6. It is possible to use
differential pressure-dependent heating circuit pumps uZ and oZ.
Central heating by heat pump
If the actual temperature captured by buffer temperature sensor zQ of
5
heating water buffer cylinder zP is lower than the set value selected
at the control unit, the heat pump, consisting of internal unit 1 and
external unit wO, starts. Heat pump 1/wO supplies heating circuits uP/
oP with heat via buffer cylinder zP.
Control unit 2 of heat pump 1/wO regulates the heating water flow
temperature subject to the outside temperature.
Secondary pump 6 in the internal unit delivers the heating water via
3-way diverter valve 5 either to heating water buffer cylinder zP or
to DHW cylinder eP. Heating circuit pumps uZ and oZ deliver the
required water volume to the heating circuits. Any heat not absorbed
by the heating circuits is stored in heating water buffer cylinder zP.
Through the matched output of the inverter controlled compressor,
long runtimes of heat pump 1/wO are achieved.
Required parameter settings
ID: 4605169_1304_08
Parameter
7000
7B00
7B0D
Vitotronic 200, type KO1B, KO2B, KW6B
Group
"General"
"General"
"General"
VIESMANN
140
(cont.)
Value Function
6 With heating circuit A1/HC1, M2/HC2, DHW cylinder
1 Enable external heat source, oil/gas
1 Enable external heat source for DHW heating
Code Function
3A : 3 Function input DE1 at EA1 extension: External blocking
3b : 2 Function input DE2 at EA1 extension: External demand
9b : 70 Set value, external demand (delivered condition)
Once the actual flow temperature value at the flow temperature sensor
inside internal unit 1 exceeds the set temperature selected at the
control unit, heat pump 1/wO and secondary pump 6 are switched
off.
Heat pump 1/wO restarts when the temperature at temperature sen-
sor zQ of heating water buffer cylinder zP has fallen below the set
value. During the power-OFF period, the heating circuits will be sup-
plied with heat from heating water buffer cylinder zP.
DHW heating
In the delivered condition, DHW heating by heat pump 1/wO is given
priority over the heating circuits and takes precedence at night. The
heat demand is issued via cylinder temperature sensor eQ and control
unit 2, which regulates secondary pump 6 and the internal 3-way
diverter valve. The control unit raises the flow temperature to the value
required for DHW heating. The cylinder temperature can be raised with
the external heat source.
Central heating with an external heat source
A demand signal is issued to external heat source tP if the heat pump
cannot maintain the required flow temperature (captured by system
flow sensor zW of the external heat source). The external heat source
starts; mixer tR initially remains closed towards the heating circuit.
Mixer tR opens towards the heating circuit only when the required flow
temperature has been reached at boiler water temperature sensor
tE of the external heat source.
The external heat source continues to operate until the set value is
reached at system flow temperature sensor zW and mixer tR is
closed.
Note
The system example is only applicable in conjunction with modulating
boilers without lower temperature limit.
Match the heating curve of the external heat source to the heating
curve of the heating circuit with the highest flow temperature. Depend-
ing on the system scope and layout, we recommend that these are
offset upwards in parallel.
System examples