SERIES 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 O-ring seal in cover. Electrical connections are easily made by removing 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.
CAUTION: For use only with air or compatible gases. Applications with hazardous atmospheres and a single positive pressure may require special venting.

Approvals:
• CE Approval, CSA Approval
• FM Approval, RoHS Letter of Compliance
• UL-Motor Controllers-US

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

Applications:
• HVAC applications
• Process applications
• All-weather applications

Specifications:

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 Connection:	3 screw type, common, normally open and normally closed.
Process Connection:	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.