Heating system types
15
Heating system types for condensing boilers
(continued)
Possible applications
For heating circuits with different
temperatures.
Please note:
This circuit diagram represents a
recommendation only. It is the
responsibility of the customer and/or
the heating contractor to check that
this recommendation is complete and
fully functional. Three-phase equipment
must be connected via additional
power contactors.
The Vitocrossal 300 is operated with
modulating boiler water temperature
by means of the outdoor re-set boiler
control unit. Two-stage or modulating
burners can be controlled.
The Vitocrossal 300 has two return
connections. The heating circuits with
the higher return temperature are
connected to the return connection
at the top, those with the lower
temperatures to the return connection
at the bottom.
Please note:
At least
15% of the take-off from the rated
output must be connected to the
return connection at the bottom.
The boiler water temperature which
is established in the heating mode is
higher than the maximum heating
circuit supply temperature by an
adjustable difference.
Pumps in the underfloor heating
circuit
sÖ
Heating circuit control unit
A
Primary pump of underfloor
heating circuit
B
High limit thermostat (max. limit)
C
Secondary pump of underfloor
heating circuit (after system
separation)
Coding
system type
Change required
Automatic change
00: 1
If no system circuit A1 is connected, set
coding ”00: 3”, ”00: 4”, ”00: 7” or ”00: 8”
(see page 114)
The system type is recognized automatically
when the sensors are connected
02: 1
Set coding ”02: 2” for operation with
modulating burner
––
0d: 1
Set coding ”0d: 0”
––
5285
941
-
0
1
20
A
B
C
20
L
N
