Viessmann Vitocal 222-G User Manual page 155

Vitocal 200-S/222-S/242-S
5.7 Vitocal 222-S/242-S, type AWT-AC, one heating circuit without mixer, DHW heating
(solar backup only for Vitocal 242-S) and active cooling via heating circuit A1
ID: 4605417_1304_03
Application range
Detached houses with uniform user patterns, underfloor heating and
cooling demand. Size the DHW cylinder in accordance with current
standards and requirements.
Main components
■ Vitocal 222-S/242-S, type AWT-AC, with Vitotronic 200 control unit,
type WO1C
■ One heating circuit without mixer
■ Integral DHW cylinder
■ Solar thermal system (only for Vitocal 242-S)
Requirements
The minimum flow rate of the heat pump must be safeguarded by sec-
ondary pump 6 and overflow valve oW. The heating line and overflow
valve must be matched up hydraulically.
Central heating by heat pump
Heat pump 1/wO starts if the actual temperature captured by the flow
temperature sensor in heat pump internal unit 1 is lower than the set
temperature selected at control unit 2. Heat pump 1 supplies heat-
5
ing circuit oP with heat. Control unit 2 in the heat pump internal unit
regulates the heating water flow temperature and thereby the heating
circuit.
Secondary pump 6 in internal unit 1 delivers the heating water via
3-way diverter valve 5 either to DHW cylinder eP or to heating circuit
oP. Opening and closing the valves at the underfloor heating system
distributor regulates the flow rate within the heating circuit. Once the
actual flow temperature value at the flow temperature sensor inside
internal unit 1 exceeds the set temperature selected at the control
unit, the heat pump and secondary pump 6 are switched off.
Required parameter settings
ID: 4605417_1304_03
Parameter
7000
7A00
C002
7100
7101
7103
7111
71FE
2003
VIESMANN
160
(cont.)
Value Function
2 With heating circuit A1/HC1, DHW cylinder
3 Solar control module, type SM1
2 Variable speed solar circuit pump with PWM activation
3 Active cooling
1 Cooling via heating circuit A1/HC1
180 Min. flow temperature, cooling
4 Cooling curve slope
1 Enable active cooling
1 Vitotrol 200A or 300B remote control activated for heating circuit A1/HC1
DHW heating by heat pump
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 the integral cylinder temperature sensor
and the control unit, which controls the integral secondary pump in
conjunction with the integral 3-way diverter valve.
The heat pump raises the flow temperature to the value required for
DHW heating.
The control unit switches the heating flow to the heating circuit via 3-
way diverter valve "Heating/DHW" 5 if the actual temperature at the
upper cylinder temperature sensor exceeds the value set at the control
unit.
The flow temperature can be raised > 60 °C via integral instantaneous
heating water heater 4.
DHW heating with solar backup (only for Vitocal 242-S)
The integral DHW cylinder will be heated by the solar thermal system
if the temperature differential between collector temperature sensor
rR and the integral cylinder temperature sensor (for solar) exceeds a
temperature differential set at control unit 2. For this, heat pump
control unit 2 controls solar circuit pump rE which is integrated into
Solar-Divicon rW.
Control unit 2 stops solar circuit pump rE again if the temperature
falls below the temperature differential.
Active cooling function
The active cooling function is enabled by control unit 2 if the value
for the cooling limit temperature that can be adjusted at control unit
2 is exceeded at outside temperature sensor 3. Heat pump 1/
wO and secondary pump 6 start. Reversing the refrigerant circuit
cools the water that is transported into cooling circuit oP.
The set flow temperature is controlled via flow temperature sensor
iU and control unit 2. Contact humidistat iE and frost stats qI
ensure that no condensation and therefore damage can occur as a
result of low temperatures.
Note
All lines where the cold water temperature can fall below the dew point
should be insulated so that they are vapour diffusion-proof.
System examples