Viessmann VITOTRONIC 100 GC1 Installation And Service Instructions Manual page 18

Heating system types
Circuit Diagram 6
Possible applications
Where the manifold is arranged in
distant substations (> 20 m). The
heat transferred to the heating circuits
is required to be reduced.
On multi-boiler systems without
Vitotronic 333, the boiler staging and
DHW tank control must be activated by
a building automation system.
The common supply pump is activated
by the master control of the building
management system. It must be
switched on when a boiler is engaged.
IMPORTANT
This circuit diagram represents a
recommendation only. It is the
responsibility of the customer and/or
heating contractor to check that this
recommendation is complete and fully
functional. Three-phase equipment
must be connected via additional
power contactors.
Available system accessories
Flue gas temperature sensor
Coding of system type
01: 1
02: 1
03: 0
0d: 2
4A: 0
18
(continued)
When the return temperature falls
below the required minimum value,
the mixing valves are partially or fully
closed via the temperature sensor T1.
The common supply pump must be
sized on the basis of 110% of the total
supply Btu/hr output rate of the heating
system.
The boiler is assured optimum
protection in conjunction with control
of the heating circuits via a Vitotronic
050 connected to the boiler control
unit. No further protective measures
are required on site.
Change required
Set coding "01: 3" for multi-boiler system
with external cascade control via switch
contacts
Set coding "02: 2" for operation with
modulating burner
Set coding "03: 1" for oil-fired operation
(re-setting is not possible)
Set coding "0d: 1"
Therm-Control is effective for the mixing
valves of the heating circuits connected
downstream
–––
Temperature sensor T1
Wiring for reducing the supply via
temperature sensor T1 in heating
systems with heating circuit control
units which are not connected via
the LON BUS to the boiler control unit.
Coding required: "4C: 2" – use plug
sÖ for closing the mixing valves of
the heating circuits connected
downstream.
sÖ A1 Close mixing valves
A
Contactor relay, field supplied
B
Heating circuit controls
connected downstream
Switch contact closed: signal
for "close mixing valve"
C
Power supply connection,
120 VAC
D
Junction box, field supplied
If an external cascade control unit is
used, the distributor pump must be
connected to the external control unit.
Automatic change
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Connection of the temperature sensor T1 at
plug aJA;
Coding is automatically changed to "4A: 1"