Boiler Sequence Control With On-Site Cascade Control Unit — Connections To The Vitotronic 100, Type Gc4B - Viessmann VITOCROSSAL 200 Type CM2 Technical Manual

Control units
(cont.)
Operation with a modulating burner
A
B
C
41
STB
TR
L1 N T1 T2 S3 B4
A Plug to the control unit
B Enable boiler; butterfly valve open or closed
C Burner stage 1 (base load) "on"
D Reduce burner output (modulation controller)
E Increase burner output (modulation controller)
F Plug to the burner
Colour coding to DIN IEC 60757
BK Black
BN Brown
BU Blue
The connections on plugs aVD and aVH are required when connecting
an external control unit. The cylinder temperature and the load-
dependent cascade control must be controlled by an external control
unit.
Note
An "enable boiler" contact is essential for multi-boiler systems.
This contact must always be closed on the lead boiler.
Boiler sequence control with on-site cascade control unit — connections to the Vitotronic 100, type GC4B
Control via contacts:
Operation with a modulating burner
Connection on plug aVD.
The cylinder temperature and the load-dependent cascade control
must be controlled by an external control unit.
Note
An boiler enable contact is essential for multi boiler systems.
This contact must always be closed on the lead boiler.
Gas condensing boilers
D
E
BN
90
BK
BU
T6 T7 T8
F
External burner start – burner stage 1
Contact at terminals "1" and "2" of plug aVD
■ Contact closed:
Burner stage 1 is switched ON.
The boiler water temperature is limited by the electronic maximum
temperature limiter (see the Vitotronic 100 service instructions), if it
is set below that of mechanical thermostat "R".
■ Contact open:
Burner stage 1 is switched OFF.
External burner start – burner stage 1 and 2
Contact at terminals "2" and "3" of plug aVD
■ Contact closed:
Both burner stages are switched ON.
The boiler water temperature is limited by the electronic maximum
temperature limiter, if it is set below that of mechanical control ther-
mostat "R".
Burner stage 2 is switched OFF 2 K sooner.
■ Contact open:
Burner stages 1 and 2 are switched OFF.
Modulating burner connection:
■ Burner stage 1fA of the Vitotronic 100
■ Plug lÖ from the Vitotronic 100 via modulation controller (on-site) to
plug lÖ on the burner.
Enable boiler, butterfly valve
Contact at terminals "2" and "3" of plug aVH
■ Contact closed:
The burner stages can be externally switched.
■ Contact open:
The butterfly valve is closed after approx. 5 min.
Burner stages cannot be started externally.
Settings at the Vitotronic 100
Code "01:3".
The high limit safety cut-out settings and other settings depend on the
system equipment level along with safety equipment to DIN EN 12828
or DIN EN 12953.
High limit safety cut-out
Temperature controller
Coding address "06" for electronic maxi-
mum temperature limiter (Vitotronic
100)
Maximum temperature of the on-site con-
trol unit
110 °C 100 °C
100 °C 87 °C
95 °C 85 °C
90 °C 80 °C
VIESMANN
93
9