Honeywell PA404 Pressuretrol Controller, 20 psi, 0.5 - 9 psi Differential, Makes at Setpoint Plus Differential On Pressure Rise; Breaks at Setpoint On Pressure Fall, SPST, Snap-Acting Switch, 24/120/240/277 V, 150 deg F, 4-15/32 Inch H x 3-3/8 Inch W x 2-1/4 Inch D, Gray
- The PA404A is a pressure actuated high limit, safety control for steam heating boilers it breaks an electrical circuit to shutdown the burner if steam pressure rises above a safe level
- The PA404B is used with suspension-type unit heaters to make the fan circuit when a pressure rise indicates the presence of steam
- Each model contains an SPST micro switch snap-acting switch
- Sensitive pressure actuated diaphragm expands or contracts with pressure variations, moving a lever mechanism which operates the snap switch
- A screw on top of the case allows setpoint adjustment without removing the cover
- Differential is adjusted by means of a dial located inside the case
Standard/Approvals: CSA LR1620, UL MP466
Application: Suspension Type Unit Heaters
