Dwyer A3000-500PA Photohelic Pressure Switch Gauge

About Dwyer A3000-500PA Photohelic Pressure Switch Gauge

Dwyer A3000-500PA Photohelic Pressure Switch Gauge Range 0-500 Pa

Dwyer A3000-500PA Photohelic Pressure Switch 

Dwyer Instruments A3000-500PA

PHOTOHELIC Pressure Switch/Gage Range 0-500 Pa.

Photohelic Switch/Gages function as versatile,highly repeatable Pressure Switches combined with a precise pressure gage employing the time-proven Magnehelic gage design.The Photohelic Switch/Gage measures and controls positive, negative or Differential Pressures of Air and Compatible Gases. Standard models are rated to 25 psig (1.7 bar) with options to 35 (2.4) or 80 (5.5 bar) psig. Single pressure 36000S models measure to 6000 psig (413 bar) with a 9000 psig (620 bar) rating. Two phototransistor actuated, DPDT relays are included for low/high limit control.Easy to adjust set point indicators are controlled by knobs located on the gage face. Individual set point deadband is one pointer width - less than 1% of full scale. Set points can be interlocked to provide variable deadband - ideal for control of fans, dampers,etc.Gage reading is continuous and unaffected by switch operation, even during loss of electrical power.Choose from full scale pressure ranges from a low 0-.25" (0-6 mm) w.c. up to 30 psi (21 bar); single positive pressure to 6000 psig (413 bar). Photohelic Sensing - How It Works In typical applications, these Dwyer switch/gages control between high and low pressure set points. When pressure changes, reaching either set point pressure, the infrared light to the limiting phototransistor is cut off by the helix-driven light shutter. The resulting phototransistor signal is electronically amplified to actuate its DPDT slave relay and switching occurs. Dead band between make and break is 1% of full scale or less - just enough to assure positive, chatter-free operation.

Product Highlights

SR Single contact, Right set point, for actuation on increasing or decreasing pressure

OLS OEM Model,less relay and transformer components and housing but including infared diodes and phototransistor(s),light shutter and set pointer(s). For single or double contact

RMR Remote-Mounted Relay, relay pack may be mounted remotely from gage. Standard length is 5 ft. For other lengths,specify cable length required

TAMP Tamper-proof knobs,low temperature option,special scales,voltages and other features and modifications are available. Special Housings available include Weatherproof (NEMA 4) and Explosion-proof (NEMA 7 & 9;NEC Cl I, Gr C&D; Cl II,Gr E,F&G; Cl III)

Scale No. 3401 Square Root Specify Range

Scale No. 3402 Blank Scale Specify Range

Range 0-500 Pa.

High & Low Latching Circuits.Dwyer Photohelic switch/gages can be wired for high-latching, low-latching or combination high-low latching circuits.That is, the equipment will hold in these respective positions once activated and until manually reset.This can be particularly useful for alarm and signal applications where control is accomplished by another Photohelic switch/gage or other means. Complete wiring and operational instructions are included. Where manual reset is required a dry circuit push button such as Dwyer Part A-601 should be used.

Dwyer A3000-500PA Specifications

Switch Specifications

Switch Type:Each set point has 2 Form C relays (DPDT)

Repeatability:1% of FS

Electrical Rating:10 A at 28 VDC,10 A at 120,240 VAC

Electrical Connections:Screw terminals.Use 167F(75C)copper conductors only

Power Requirements:120 VAC,50/60 Hz,240 VAC and 24 VAC power optional

Mounting Orientation:Diaphragm in vertical position. Consult factory for other position orientations

Set Point Adjustment:Adjustable knobs on face

Agency Approvals:CE,CSA,UL

Gauge Specifications

Service:Air and non-combustible, compatible gases

Accuracy:2% of FS at 70F(21.1C),3% on -0,4% on -00 models

Pressure Limits:-20"Hg to 25 psig(-0.677 to 1.72 bar),MP option;35 psig (2.41 bar),HP option;80 psig (5.52 bar)

Temperature Limits:20 to 120F.(-6.67 to 48.9C),-20 to 120F(-28 to 48.9C) with low temperature option

Process Connections:female NPT

Dimensions:4"(101.6 mm) dial face,5 x 8"(127 x 209.55 mm)

Weight:4 lb (1.81 kg)

High-Precision Pressure Measurement

This Photohelic Pressure Switch Gauge offers accurate and reliable performance with a range of 0-500 Pa and 2% full-scale accuracy at standard temperature. Its distinctive 4-inch dial ensures clear, easy-to-read measurements, which is vital for monitoring critical processes involving air and compatible gases.


Versatile and Robust Construction

Crafted from durable metal alloys and available with a variety of attractive finishes, the Dwyer A3000-500PA is built for industrial environments. The matte, polished, galvanized, or antique finishes not only provide visual appeal but also enhance longevity and resistance to wear, making this gauge suitable for demanding applications.


Simple Installation and Operation

Designed for panel mounting, this pressure switch gauge is straightforward to install within control panels or machinery panels. Its user-friendly interface, including a large aluminum pointer and plastic dial, makes it easy to observe and manage pressurized systems, ensuring safety and process efficiency.