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5693 982 - 04
Vitotronic 300, GW2B Installation and Service
Optional connections:
H
Plug
abÖ
(See page 44)
H
Plug
a
V
D
H
Extension EA1 (accessory, see page 127)
External Blocking via Switching Contact
Note:
The heating system has no frost protection during
blocking.
The boilers are not held at the lower boiler water
temperature.
Installation Sequence
Connection
Note:
‘Live’ contacts lead to short circuits or phase
failure. The external connection must be floating.
Codes
Plug
a
V
D
Extension EA1
Set coding address “99” in the “General” group.
Set “5d”, “5E” or “5F” in the “General” group to 3 or 4.
Plug
a
V
D
Extension EA1
Legend
A
Floating contact
B
Plug
a
V
D
of the control unit
Legend
A
Floating contact
B
Extension EA1
Closing this contact leads to a controlled burner shutdown.
Any connected shunt or boiler circuit pump is stopped.
