System Example 7 - Viessmann VITOSOLIC 200 Installation And Service Instructions Manual

System examples

System example 7

DHW heating with mono-mode DHW cylinder and central heating
backup with multi-mode heating water buffer cylinder
Main components
■ Viessmann solar collectors
■ DHW cylinder Vitocell 100-V or
Vitocell 300-V
■ Multi-mode heating water buffer cylin-
der Vitocell 340-M or Vitocell 360-M
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 rP is
heated up if the temperature differential
between collector temperature sensor
S1 eQ and cylinder temperature sensor
S2 rQ 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 rR (if installed)
Entire heating water buffer cylinder rP is
heated by the solar thermal system if the
insolation is adequate for DHW heating.
48
If there is inadequate solar energy, the
DHW in the lower part of heating water
buffer cylinder rP is preheated by solar
energy, and heated to the required tem-
perature in DHW cylinder qP by boiler
1.
A temperature-controlled DHW stratifi-
cation is not possible.
DHW heating without solar energy
DHW cylinder qP is heated by
boiler 1. The cylinder thermostat with
cylinder temperature sensor 3 of boiler
control unit 2 regulates the circulation
pump for cylinder heating 4.
Central heating with solar energy
Three-way diverter valve R6 rZ is
switched to position "AB-A" and the heat-
ing return water is routed to boiler 1 via
heating water buffer cylinder rP, if the
temperature differential between buffer
cylinder temperature sensor S5 rW and
heating circuit return temperature sensor
S6 rT exceeds start temperature differ-
ential ΔT6on. If the temperature of the
preheated return water is too low, boiler
1 reheats the water to the required flow
temperature. Three-way diverter valve
R6 rZ is switched to position "AB-B" if
the actual temperature falls below the
stop temperature differential ΔT6off.