Hook-Up Of On-Site Control Units Via Lon - Viessmann VITOCROSSAL 200 Type CM2 Technical Manual

Control units
(cont.)
1 2 3
9
143
A Blocking the boiler externally
(floating contact for switching LV)
B Start the boiler externally as the last one in the boiler sequence
(floating contact for switching LV)
Con- Closed
tact
A – The boiler is blocked and
has been removed from
the boiler sequence.
– Butterfly valve is closed
and the boiler circuit
pump stops.
– The other boilers provide
the required heating.
B This boiler is started if the
other boilers in the heating
system cannot provide suf-
ficient heat.
External control of the modulating burner
Make connections at plug aVH and aBÖ.
Note
The contact at terminals 2 and 3 of plug aVH is always required to
prevent boiler damage.
This contact must always be closed on the lead boiler.

Hook-up of on-site control units via LON

The Vitotronic control units are equipped with an open standard LON
interface. With standard LONWORKS network variables (SNVT).
This universal, decentralised network for automated building control
systems not only allows communication between Vitotronic control
units, but also the hook-up of on-site systems and devices from various
manufacturers.
VIESMANN
94
A
B
Open
The boiler is integrated into
the current boiler sequence.
The boiler is integrated into
the current boiler sequence.
B4 S3 T2 T1 N L T6 T7 T8
41
F
A/B Boiler enable from on-site modulation controller (butterfly
valve open)
A Floating contact for switching LV
B Floating contact for switching 230 V~
C Burner base load
(floating contact for switching 230 V~)
D T6, T7: Reduce burner output (modulation controller closed)
(floating contact for switching 230 V~)
E T6, T8: Increase burner output (modulation controller open)
(floating contact for switching 230 V~)
F Plug to the burner
G Plug to the control unit
Note
If the boiler is enabled via a contactor, the conditions of safety category
II and the operation of safety LV (SELV) must be ensured.
Contact Closed
A/B Boiler enabled. The butter-
fly valve opens.
C Burner on (base load). An
on-site modulation control-
ler regulates the load-de-
pendent modulation. The
boiler water temperature is
restricted by the electronic
maximum temperature lim-
iter.
It enables, for example, individual room control units or building man-
agement systems to be directly connected to Vitotronic control units.
Further information can be found in the LON manual; see
www.viessmann.de\lon.
G
B
A
C
90
Open
The butterfly valve is closed
after approx. 5 s. External
burner start not possible.
Burner off.
Gas condensing boilers
D
E