System Example 5 - Viessmann VITOSOLIC 200 Installation And Service Instructions Manual

System example 5

DHW heating and central heating backup with a multi-mode heat-
ing water buffer cylinder
Main components
■ Viessmann solar collectors
■ Vitocell 340-M or Vitocell 360-M multi-
mode heating water buffer cylinder
with integral DHW heating, with or
without stratification system
■ Vitosolic 200
■ Solar-Divicon
■ Wall mounted oil/gas boiler or oil/gas
boiler
Function description
DHW heating with solar energy
Solar circuit pump R1 eE starts and
heating water buffer cylinder qP is
heated up if the temperature differential
between collector temperature sensor
S1 eQ and cylinder temperature sensor
S2 qQ is greater than the start tempera-
ture differential ΔTon.
Solar circuit pump R1 eE is stopped in
accordance with the following criteria:
■ Actual temperature dropping below
the stop temperature differential ΔToff
■ Exceeding the electronic temperature
limit of control unit eZ (max. 90 °C)
■ Reaching the temperature selected at
high limit safety cut-out qW (if installed)
Entire heating water buffer cylinder qP is
heated by the solar thermal system if the
insolation is adequate.
The upper part of heating water buffer
cylinder qP will only be reheated by
boiler 1 if the actual water temperature
falls below the set temperature selected
at boiler control unit 2.
If the solar energy is inadequate to cover
the entire heat demand, the DHW in the
lower part of heating water buffer cylin-
der qP will be preheated by solar energy.
The DHW in the upper part of the cylin-
der is heated to the required temperature
by boiler 1.
Suppression of DHW cylinder reheat-
ing by the boiler
Coding address "67" in boiler control
unit 2 defaults a third set DHW tem-
perature (setting range 10 to 95 °C). This
value must be below the first set DHW
temperature. The DHW cylinder will only
be heated by the boiler (solar circuit
pump R1 eE runs) if this set value cannot
be achieved by the solar thermal sys-
tem.
DHW heating without solar energy
The upper area of heating water buffer
cylinder qP is heated by boiler 1. The
integral instantaneous water heater/
standby section is heated by the sur-
rounding buffer cylinder water.
The cylinder thermostat with cylinder
temperature sensor 3 of boiler control
unit 2 regulates circulation pump for
cylinder heating 4.
System examples
35