PA pressure switch

The pressure switch responds to a rise or fall in system pressure by either breaking or completing an electrical circuit. The switch can be used several ways in the pressure washer system. It can be used as a fluid control device in conjunction with the trigger gun. When the gun valve closes, the increase in pressure throws the pressure switch and shuts off all power to the system. When the gun valve re-opens, pressure in the line is relieved , the switch closes, and power is restored to the system.
When used as a boiler control, the switch is activated to complete a circuit to supply power to the burner assembly. When system pressure increases, the switch is activated to complete the circuit to the burner. When pressure falls the switch plunger returns to its normal position.

PRESSURE SWITCH WIRING:
 
The electrical portion of the switch is wired with three leads. Two leads are used , depending upon whether the switch is intended to be normally on or nor