Series 1831 DPDT Low Differential Pressure Switch

Brand: Dwyer Instruments, LLC

One Dwyer's most popular differential pressure switches is now available with a DPDT switch and manual reset.

The 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 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.
  • No power to operate DPDT switch means no additional wiring or conduit reduces material and installation labor costs
  • Easy access for modifying set point simplifies adjustment
  • Both control contacts activate at the same time eliminating system issues where lead switch activities preventing the lagging switch from sending a signal


Adjustment Type

  • Factory Set (Pre-Set)
  • Field Adjustable

Diaphragm Material

  • Nitrile
  • Silicone-Free

Electrical Connectors

  • Screw Typical Terminal Block

Electrical Rating

  • 3A inductive 30 Vdc
  • 5 A Resistive 30 Vdc
  • 4 A at 125/250 Vac


  • Diaphragm in Vertical Position

NPT Connection

  • 1/8” NPT Female

O-Ring Material

  • Silicone Rubber

Proof Pressure

  • bar: 1.7
  • kPa: 172.37
  • psig: 25


  • ± 4 %, Max.

Set Point - Decreasing

  • Inches WC: 2.5 to 23

Set Point - Increasing

  • Inches WC: 2.5 to 23

Switch Type

  • DPDT
  • SPDT

System Pressure

  • bar: 0.68
  • kPa: 68.95
  • psig: 10

Temperature Range

  • -34° to 82.2° C (-30° to 180° F)

  • High Duct Static Cutout Applications
  • HVAC
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