Provisional Burner Operation - Viessmann Vitotronic 300 GW6B Installation Instructions Manual

Vitotronic 300, GW6B Installation and Service

Provisional Burner Operation

Legend
A Dry contact between "TR and ON"
B Din rail (located in junction box)
Legend
C To burner interface
T6 - Common
T7 - Modulating Down
T8 - Modulating Up
Remove jumper across terminals 23 (L) and 24 (L) (not
shown) and connect terminals 23 (L) and 25 (L) external
control via dry contact (heat demand on close). Upon heat
demand the boiler will maintain low fire until modulation is
externally controlled through BMS.
External modulation via 90 plug (dry contact for
modulation) terminal closure T6 and T8 will drive burner
modulation up and terminal closure T6 and T7 will drive
modulation down.
Note: Only one contact will be closed at a time. Both
contacts open will hold modulation.
Temperature control is now limited by the electronic high
limit setting in the burner control.
Refer to the "combustion controller" group in
coding for adjustment to maximum boiler water
temperature.
Electrical Connections
39