Viessmann Vitolig
200 Technical Manual page 36

4 Vitolig 200
4.6 Application examples
Application example 1
and one or two heating circuits with mixer
Notes
The temperatures stated in the
application example are standard values;
set alternative values according to the
relevant requirements.
The heating circuits and one DHW
cylinder are heated by Vitolig and one
heating water buffer storage unit.
Combustion controller and control of the
Vitolig circulation pump
After Vitolig has been heated up, it is
operated at full load. The boiler circuit
pump 3 is switched on, when Vitolig
reaches a boiler water temperature of
60 ºC.
Either the heating circuit or the DHW
cylinder are heated up. The heat not
drawn off by consumers is transferred to
the heating water buffer storage unit.
The layer load operation begins, if 70 ºC
is exceeded for longer than 30 min. at
sensor qE at the top of the heating water
buffer storage unit.
Vitolig is operated at 50% output and the
heating water buffer storage unit is
heated up to 80 ºC boiler water
temperature.
The layer load operation ceases, if the
temperature at the top of the heating
water buffer storage unit at sensor qE
falls below 70 ºC. The boiler output is
enabled and the boiler water temperature
regulated to 70 ºC.
The Vitolig boiler circuit pump 3 is
switched off by the differential
temperature control, if the heating water
buffer storage unit is heated up and the
boiler water temperature is below that at
the bottom of the buffer (T
PU
sensor qR.
At temperatures below 50 ºC, the
Vitolig boiler circuit pump 3 is switched
off independent of the differential
temperature control.
36
Vitolig 200 incl. DHW cylinder, heating water buffer storage unit
Return temperature raising facility
Vitolig requires a minimum return
temperature of 45 ºC. When the boiler
circuit pump 3 is switched on, the
mixing valve 4 opens the path from the
heating return to Vitolig in line with the
increasing return temperature and
simultaneously closes the path from the
flow to the return (bypass).
DHW heating with priority control
Initially, the DHW is heated up when
Vitolig is started. Space heating is only
provided afterwards.
The Vitolig boiler water temperature is at
least 60 ºC, and the boiler circuit pump
3 runs to raise the return temperature.
The DHW circulation pump runs to
heat−up the DHW cylinder 5, if the DHW
cylinder temperature lies below the value
set at the remote control of the heating
circuit control unit and the value recorded
by the temperature sensor qE of the
heating water buffer storage unit lies 10 K
higher than that of the DHW cylinder. If
the flow rate of the circulation pump 3
is higher than that of circulation pump
5, any surplus heat will be transferred to
the heating water buffer storage unit. The
three−way mixer 8 of the heating circuit
is closed when DHW is heated. The
circulation pump 5 is switched off,
when the set temperature has been
reached, the three−way mixer opens,
transferring heat into the heating circuit.
DHW heating without priority control
Set the coding switch "S2" on the heating
circuit control unit to "Off" to avoid
setting a priority. Depending on the
prevailing demand, either DHW and/or
space heating is provided, when Vitolig
starts up.
In that case both circulation pumps 5
+ 5K) at
and 7 transfer heat from Vitolig and
from the heating water buffer storage unit
to the relevant consumer(s).
DHW heating through the
heating water buffer storage unit
The Vitolig boiler water temperature lies
below 55 ºC; the temperature of the
heating water buffer storage unit at
temperature sensor qE lies 10 K above
the DHW temperature set at the remote
control. When DHW heating is requested
the DHW circulation pump 5 activates,
and the DHW cylinder is heated by the
heating water buffer storage unit.
Heating mode
The heat created by Vitolig is transferred
via circulation pump 3 to the heating
circuit and to the heating water buffer
storage unit. The heat not required by the
heating circuit is transferred to the
heating water buffer storage unit.
If the Vitolig boiler water temperature
falls, a greater amount of heat is drawn
from the heating water buffer storage unit
in line with the amount by which the
mixing valve 4 of the return
temperature raising facility opens the
path from the boiler flow (bypass).