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Dwyer Series 1831

Series 1831 DPDT Low Differential Pressure Switches

Dwyer Series 1831
Series 1831

Manual Reset, No Power Required

One of our most popular differential pressure switches is now available with a DPDT switch and manual reset. The Dwyer Series 1831 combines small size with 4% set point repeatability. Absolutely no power is required to operate the DPDT switch. Set point adjustment on the switch is easily accessible for modifying the set point.

The Series 1831 DPDT Low Differential Pressure Switches with Manual Reset eliminate common problems associated with typical high duct static cutout installations. Since the Dwyer Series 1831 requires absolutely no power to drive its outputs, a separate power loop and its associated additional wiring and conduit is alleviated, reducing material and labor installation costs. Both control contacts of the Series 1831 activate at the same time. The potential of the lead switch shutting down the fan preventing the lag switch from sending an alarming signal to the DDC is no longer a probable system liability. Potential costly maintenance calls are diminished. Unlike typical switches that posses only a single conduit entry for both control loops, the Series 1831 provides two conduit connections simplifying wiring while eliminating additional conduit tees. The Series 1831’s specifications and features make it the superior choice for high duct static cutout applications.


Dwyer Series 1831 Specifications

  • Service:Air and non-combustible, compatible gases.
  • Wetted Materials:Consult factory.
  • Temperature Limits:-30 to 180°F (-34 to 82.2°C).
  • Pressure Limits:10 psig (68.95 kPa) continuous, 25 psig (172.4 kPa) surge.
  • Switch Type:2 SPDT.
  • Actuation Time Difference:1 millisecond maximum actuation delay between contacts.
  • Repeatability:±4% max.
  • Electrical Rating:4A @ 125/250 VAC.
  • Electrical Connections:Screw type terminal block.
  • Process Connections:1/8″ female NPT.
  • Mounting Orientation:Diaphragm in vertical position. Consult factory for other position orientations.
  • Set Point Adjustment:Screw type inside mounting spud.
  • Weight:1 lb 2 oz (522 g).



  • Both contacts activate and reset at the same time
  • No power required to operate
  • Dual conduit openings for each control loop
  • Included bracket for mounting quickly



Popular Models

  • Model 1831-1-RA-S Differential pressure switch, manual reset, DPDT, activate on increase, silicone diaphragm, range 2.5-9″ w.c.
  • Model 1831-2-RA-S Differential pressure switch, manual reset, DPDT, activate on increase, silicone diaphragm, range 7.5-23″ w.c.