Connection Of On-Site Control Units To Ea1 Extension In Multi Boiler Systems With On-Site Cascade Control Unit - Viessmann VITOCROSSAL 200 Type CM2 Technical Manual

Control units
(cont.)
Plug aVD at Vitotronic 100, type GC1B and GC4B
1 2 3
143
A Boiler blocking
B Start boiler as the last one in the boiler sequence
A and B are floating contacts.
Connection of on-site control units to EA1 extension in multi boiler systems with on-site cascade control
unit
Control via 0 – 10 V input:
External demand via 0 – 10 V input
Connection to the 0 – 10 V input at EA1 extension on each Vitotronic
100 (accessories).
In conjunction with two-stage or modulating burners.
Set code "01:3".
[{{] 0-10V aBJ f-]
A
+ - S P Ö L
­
U
+
Enable boiler without an additional enable contact
0 to 1 V
■ Boiler blocked.
■ Butterfly valve closed.
■ Boiler circuit pump or shunt pump off.
1 to 10 V
■ Boiler water temperature default
≙ Set value 10 °C
1 V
10 V ≙ Set value 100 °C
■ Boiler enabled; held at minimum temperature.
■ Butterfly valve open.
■ Boiler circuit pump or shunt pump enabled.
Gas condensing boilers
A
B
fÖ
N N L
Boiler blocking
■ Contact A closed:
The boiler is blocked and will be removed from the boiler sequence.
This means the butterfly valve is closed and the boiler circuit pump
is stopped. The heat demand has to be met by the other boilers.
Note
The heating system is not protected against frost if all boilers are
blocked or when no other boilers area ready for operation.
■ Contact A open:
The boiler is reinstated into the current boiler sequence.
Start boiler as the last one in the boiler sequence
■ Contact B closed:
The boiler is started as the last one in the boiler sequence.
The heat demand of the heating system is met by the other boilers.
This boiler is started if the output of the other boilers is insufficient.
■ Contact B open:
The boiler is reinstated into the current boiler sequence.
Note
Only for low temperature boilers:
On the lead boiler, the voltage must be higher than 1 V.
Note
Ensure DC separation between the negative pole and the earth con-
ductor of the on-site voltage source.
Enable boiler with an additional enable contact
0 - 1 V ≙ "No default set boiler water temperature"
≙ Set value 10 °C
1 V
≙ Set value 100 °C
10 V
1 2 3
146
A Boiler enable
(floating contact)
Note
This contact must always be closed on the lead boiler.
Contact Closed
A Boiler enabled; held at min-
imum temperature. The but-
terfly valve opens.
Digital data inputs DE1 to DE3
Functions:
■ External blocking
■ External blocking with fault message input
■ Fault message input
The hooked-up contacts must correspond to safety category II.
A
Open
The butterfly valve is closed
after approx. 5 min. External
burner start not possible.
VIESMANN
9
91