Viessmann Vitocal 222-G User Manual page 222

Vitocal 300-A/350-A
7.6 Vitocal 300/350-A, one heating circuit without mixer, two heating circuits with mixer,
DHW heating, heating water buffer cylinder and external heat source (dual mode parallel
operation)
ID: 4605059_1304_06
Application range
Detached houses and apartment buildings with up to three heating
circuits with different utilisation patterns. Size the DHW cylinder in
accordance with current standards and requirements.
Main components
■ Vitocal 300/350-A with Vitotronic 200, type WO1B
■ Heating circuit distributor with one heating circuit without mixer and
two heating circuits with mixer
■ DHW cylinder, external heat exchanger
■ Heating water buffer cylinder
■ External heat source with Vitotronic 200, type KO1B, KO2B, 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, oZ and q-
Z.
Note
In type AWCI, circulation pump for cylinder heating 5 is replaced by
an internal and fully wired 3-way diverter valve.
Central heating by heat pump
Heat pump 1 starts when the actual temperature captured by cylinder
temperature sensor zQ of heating water buffer cylinder zP falls below
the set temperature selected at the control unit.
Heat pump 1 supplies the heating circuits with heat. Control unit
2 of heat pump 1 regulates the heating water flow temperature and
thereby the heating circuits. The secondary pump 6 delivers the
heating water either to heating water buffer cylinder zP or to DHW
cylinder eP. Heating circuit pumps uZ, oZ and q-Z 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.
Required parameter settings
ID: 4605059_1304_06
Vitotronic 200, type WO1B
Parameter
7000
7B00
7B0D
ID: 4605059_1304_06
Vitotronic 200, type KO1B / KO2B / KW6B
Parameter Value
General 3A : 3
General 3b : 2
General 9b : 70
System examples
(cont.)
Value Function
10 With heating circuit A1/HC1, M2/HC2, DHW cylinder
1 Enable external heat source, oil/gas
1 Enable external heat source for DHW heating
Function
Blocking of the external heat source
External demand with set flow temperature (setting SA : 9b)
Set value for external demand (delivered condition)
Heat pump 1 and secondary pump 6 are switched off once the
actual return temperature at the return temperature sensor exceeds
the temperature set at the control unit.
Any heat not absorbed by the heating circuits is stored in heating water
buffer cylinder zP. This achieves a long runtime for the heat pump.
Heat pump 1 restarts when the actual temperature at temperature
sensor zQ of heating water buffer cylinder zP falls below the set value.
The heat pump stops again when the set temperature at the heat pump
return is reached.
During the power-OFF period, the heating circuits will be supplied with
heat from heating water buffer cylinder zP.
DHW heating
In the delivered condition, DHW heating by heat pump 1 is given
priority over the heating circuits and takes precedence at night.
The heat demand is issued via cylinder temperature sensor eW and
control unit 2, which controls circulation pump for cylinder heating
5 in conjunction with secondary pump 6 and cylinder loading pump
eE. The temperature of the DHW cylinder is raised by heat pump con-
trol unit 2 to the set value selected at the control unit.
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 temperature sensor zW). External heat source tP starts; mixer
tR initially remains closed towards the heating circuit. Mixer tR opens
towards the heating circuit only when the required temperature has
been reached at boiler water temperature sensor tE of external heat
source tP. Mixer tR closes towards the heating circuit when the
required flow temperature has been achieved.
External heat source tP stops if mixer tR is closed towards the heating
circuit and the flow temperature (captured at system flow temperature
sensor zW) no longer falls below an adjustable threshold value for a
specified time. There then is either no heat demand or heat pump
1 is delivering sufficient heat.
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.
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VIESMANN
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