Connection Of External Equipment To Plug Avh - Viessmann VITOTRONIC 300 GW2 Installation And Service Instructions Manual

Connection of external equipment to plug aVH

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A External demand (floating contact)
B External changeover,
staged/modulating burner
(floating contact)
B
A
Installation
External demand
Connect floating contact to
terminals "2" and "3".
The burner of the boiler is switched
in on a load-dependent basis when
the floating contact is closed.
The boiler water temperature is
limited by the preset max. boiler
water temperature or by the value
set on the mechanical adjustable
high limit.
The required boiler set-point value is
set via the coding address "9b".
External changeover between
staged/modulating burner
Connect floating contact to
terminals "1" and "2".
Contact open: modulating
operation
Contact closed: two-stage
operation
The burner type must be set to
"modulating" in coding 1
(coding "02: 2").
Please note:
When the burner type is scanned,
"modulating" continues to be
displayed after external changeover
(the display is not changed).
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