Dwyer 1950-5-2F Explosion-Proof Differential Pressure Switch

Safe and reliable monitoring for hazardous areas. The Dwyer 1950-5-2F is a rugged differential pressure switch with an explosion-proof enclosure. It's ideal for monitoring filters, fans, or duct pressure in potentially explosive atmospheres.

Key Features

• Hazardous Location Rated: FM Approved for Class I Div 1 & Class II Div 1 (Groups C, D, E, F, G).
• All-in-One Design: Integral explosion-proof and weatherproof (IP54/NEMA 3) housing eliminates need for a separate enclosure.
• Easy Adjustment: Set point is easily adjusted from outside the housing with a screw.
• Versatile Switching: SPDT (Single-Pole, Double-Throw) switch allows for either alarm or control circuit wiring.
• Robust Electrical Rating: Handles up to 15A @ 480V AC, suitable for directly switching fan or pump contactor coils.

Complete Technical Specifications

Brand: Dwyer Instruments
Model: 1950-5-2F
Series: 1950 Series Explosion-Proof Pressure Switches
Type: Differential Pressure Switch
Set Point Range: 0.5 to 50 psi (0.035 to 3.5 bar) [Model Specific]
Switch Action: Single-Pole, Double-Throw (SPDT)
Electrical Rating: 15 A @ 125, 250, 480 VAC, 60 Hz (Resistive)
Motor Rating: 1/8 HP @ 125 VAC, 1/4 HP @ 250 VAC, 60 Hz
Process Connection: 1/8" Female NPT (x2)
Enclosure Ratings: NEMA 3, 7, 9; IP54 (Weatherproof & Explosion-Proof)
Agency Approvals: FM, UL, CSA, CE
Hazardous Location Class: Class I, Division 1, Groups C & D; Class II, Division 1, Groups E, F, G; Class III
Media: Air and Non-Combustible, Compatible Gases
Operating Temperature: -40°F to +140°F (-40°C to +60°C)
Pressure Limit (Continuous): 35 psi (2.41 bar) for 'P' series models.
-Mounting: Diaphragm must be in a vertical position.
Weight: 3.25 lbs (1.5 kg)
Wiring: 3 screw terminals (Common, Normally Open, Normally Closed)

Installation & Setup

Mount the 1950-5-2F switch securely with the diaphragm in a vertical position. Connect the high and low pressure sensing lines to the two 1/8" NPT ports. Wire the electrical connections to the common (C), normally open (NO), and normally closed (NC) terminals according to your control circuit needs. Apply pressure to the sensing lines and adjust the set point screw on the top of the housing until the switch activates at the desired differential pressure. Ensure all covers are tightly sealed to maintain the explosion-proof and weatherproof integrity.

Expert FAQs

What is the "5-2F" in the model number?
It indicates the specific pressure range and switch configuration. In the 1950 series, this denotes a model with a set point range of 0.5 to 50 psi.

Can this switch be used for liquid pressure?
The specifications state "Air and non-combustible, compatible gases." Using it with liquids may damage the diaphragm. Consult the factory for liquid media applications.

Why is vertical mounting required?
The diaphragm's movement is gravity-sensitive. Mounting it vertically ensures accurate and repeatable switching by preventing the diaphragm's weight from affecting the set point.

What is the difference between NEMA 7 and NEMA 9?
NEMA 7 is for hazardous gas atmospheres (Class I). NEMA 9 is for hazardous dust atmospheres (Class II). This switch is approved for both.

Can I use it in a safe area just for its weatherproof (IP54) feature?
Yes. Its robust IP54/NEMA 3 rating makes it an excellent choice for outdoor or washdown applications even outside hazardous locations.

Package & Warranty

Package Includes:
1 x Dwyer 1950-5-2F Pressure Switch
1 x Installation Sheet

Warranty: This product is covered by a 12-month warranty.

Shipping: We ship internationally via FedEx, UPS, and DHL.

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