Pressure Switch; Information On Commissioning - Viessmann Vitoplex 200 SX2A Installation Instructions For Contractors

Pressure switch

Pressure switch
The pressure switch is a safety accessory and is
required for every boiler to EN 303 with pressure-jet
burners to EN 676 (third party burners) for shutting
down the burner in case of flue gas back pressure/
condensate banked up in the boiler/flue system.
The adjustable, interlocking pressure switch is connec-
ted to the control unit safety chain, and to an additional
pressure measuring connector for "combustion cham-
ber pressure". The control unit safety chain is connec-
ted in series to the maximum pressure switch, the min-
imum pressure switch and the high limit safety cut-out.
A setting of approx. 2 mbar above the actual combus-
tion room pressure in full load operation ensures the
burner will shut down used in the event of a fault. The
pressure is measured in full load operation upstream
of the pressure switch.

Information on commissioning

Service instructions for boiler and boiler control
unit plus separate burner documentation
Note
The hose for measuring the pressure is also connec-
ted to the combustion chamber sight glass.
"Pressure switch set" installation instructions
25