Dwyer 1950 Explosion-proof Differential Pressure Switch Low

Dwyer 1950 Explosion-Proof Differential Pressure Switch combines the best features of the popular Dwyer® Series 1900 Pressure Switch with an integral explosion-proof and weatherproof housing, making it an exceptional value for either application. It is CE, UL and CSA listed, FM approved for use in Class I, Div 1, Groups C and D, Class II Groups E, F, and G, and Class III hazardous atmospheres (NEMA 7 & 9), Raintight NEMA 3 (IP54). Weatherproof features include a drain plug and an O-ring seal in the cover.

Electrical connections are easily made by removing the front cover. For convenience, the set point adjustment screw is located on the outside of the housing. Twelve models offer set points from .03 to 20 in w.c. (0.0075 to 5 kPa) and from .5 to 50 psi (0.035 to 3.5 bar). The unit is very light and compact — about half the weight and bulk of other explosion-proof or weather-proof switches with separate enclosures.

Dwyer 1950 Explosion-proof Differential Pressure Switch

Known for quality, reliability, and accuracy, Dwyer designs and manufactures a full-line of Controllers, Data Loggers, Gages, Manometers, Monitors, Remote Displays, Switches, Transmitters, and Accessories to measure, monitor, and control pressure, air velocity, flow, fan pressure, duct, and more.

Dwyer’s wide selection extends to Gages, Transmitters, Switches, Data Loggers, and Monitors for Differential Pressure. Dwyer manufactures a range of dial and digital gages to reliably measure and display pressure difference, between two pressure sources using gas or liquid in a process flow.

Sensors for air and non-combustible compatible gases have an electrical contact output at a specific difference between two pressures. Applications vary between the different types of differential pressure switches. A wide variety of switches and circuit styles enables control functions needed for any system.


  • Explosion-proof and weatherproof housing provides device protection for outdoor use or harsh environment operation
  • External set point screw provides easy access that simplifies making adjustments without opening or disassembling enclosure
  • Easily accessible electrical connection simplifies the installation


  • HVAC applications
  • Process applications
  • All-weather applications

Dwyer 1950 Explosion-proof Specification

Service Air and non-combustible, compatible gases.
Wetted Materials Consult factory.
Temperature Limits -40 to 140°F (-40 to 60°C); 0 to 140°F (-17.8 to 60°C)for 1950P-8, 15, 25, and 50. -30 to 130°F (-34.4 to 54.4°C) for 1950-02.
Pressure Limits Continuous: 1950’s – 45″ w.c. (0.11 bar); 1950P’s – 35 psi (2.41 bar); 1950P-50 only – 70 psi (4.83 bar). Surge: 1950’s – 10 psi (0.69 bar); 1950P’s – 50 psi (3.45 bar); 1950P-50 only – 90 psi (6.21 bar).
Enclosure Rating NEMA 3 (IP54), NEMA 7 and 9.
Switch Type Single-pole double-throw (SPDT).
Electrical Rating 15 A @ 125, 250, 480 VAC, 60 Hz. Resistive 1/8 HP @ 125 VAC, 1/4 HP @ 250 VAC, 60 Hz.
Electrical Connections 3 screw type, common, normally open and normally closed.
Process Connections 1/8″ female NPT.
Mounting Orientation Diaphragm in vertical position. Consult factory for other position orientations.
Set Point Adjustment Screw type on top of housing.
Weight 3.25 lb (1.5 kg); 1950-02 model 4.4 lb (2 kg).
Agency Approvals CE, CSA, FM, UL.

Download Data Sheet: Series 1950 Explosion-proof Differential Pressure Switch

Ref: dwyer-inst.com

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