The 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 0.03 in W.C. - 20 in W.C. (0.0075 kPa - 5 kPa) and from 0.5 PSI - 50 PSI (0.035 Bar - 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.
The series 1950G Explosion-Proof Switch combines the best features of the popular Dwyer® Series 1950 Pressure Switch with the benefit of natural gas compatibility. Units are rain-tight for outdoor installations, and are UL listed for use in Class I, Groups A, B, C, & D; Class II, Groups E, F, & G and Class III atmospheres, Directive 2014/34/EU (ATEX) Compliant for CE ATEX II 2G Exd IIB+H2 T6, CSA & FM approved for Class I, Div. 1, Groups B, C, D; Class II, Div. 1, Groups E, F, G and Class III atmospheres IECEx Ex d IIB+H2 T6 (-40°C < Ta < +60°C). The 1950G is very compact, about half the weight and bulk of equivalent conventional explosion-proof switches.
Easy access to the SPDT relay and power supply terminals is provided by removing the top plate of the aluminum housing. A supply voltage of 24 VDC, 120 or 240 VAC is required. A captive screw allows the cover to swing aside while remaining attached to the unit. Adjustment to the set point of the switch can be made without disassembly of the housing.
CAUTION: For use only with air or compatible gases. Applications with hazardous atmospheres and a single positive pressure may require special venting. Select the 1950G for use with natural gas.
• Explosion-proof and weatherproof housing provides device protection for outdoor use or harsh environment operation
• Compatible with natural gas (1950G only)
• External set point screw provides easy access that simplifies making adjustments without opening or disassembling enclosure
• Easily accessible electrical connection simplifies the installation
|Service||Air and non-combustible, compatible gases (for use with combustible gases, use the 1950G)|
|Wetted Materials||Consult factory|
|Temperature Limits*||1950: -40°F - 140°F (-40°C - 60°C)
0°F - 140°F (-17.8°C - 60°C) for 1950P-8, 15, 25, and 50.
-30°F - 130°F (-34.4°C - 54.4°C) for 1950-02
1950G: 0°F - 140°F (-17°C - 60°C)
|Pressure Limits||Continuous: 1950's - 45 in 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)
1950G: 45 in W.C. (11.2 kPa) continuous; 10 PSIG (68.95 kPa) surge
|Enclosure Rating||NEMA 3 (IP54), NEMA 7 and 9|
|Switch Type||1950: Single-pole double-throw (SPDT)
1950G: 1 form C relat (SPDT)
|Electrical Rating||1950: 15 A @ 125, 250, 480 VAC, 60 Hz. Resistive 1/8 HP @ 125 VAC, 1/4 HP @ 250 VAC, 60 Hz
1950G: 10 A, 120/240 VAC, 28 VDC. Resistive 50 mA, 125 VDC
|Electrical Connections||1950: 3 screw type, common, normally open and normally closed
1950G: Internal terminal block
|Process Connections||1/8 in female NPT|
|Mounting Orientation||Diaphragm in vertical position|
|Set Point Adjustment||Screw type on top of housing|
|Weight||1950: 3.25 lb (1.5 kg); 1950-02 model 4.4 lb (2 kg)
1950G: 2 lbs 15.7 oz (1.35 kg)
|Agency Approvals||1950: CE, CSA, FM, UL
1950G: ATEX, CE, CSA, FM, IECEx, UL
|*Set point drift may occur with ambient temperature changes|
• HVAC applications
• Process applications
• All-weather applications
• Natural gas applications (1950G only)