Dwyer A3000-750PA Photohelic Pressure Switch Gauge Range 0-750 PA

About Dwyer A3000-750PA Photohelic Pressure Switch Gauge Range 0-750 PA

Dwyer A3000-750PA Photohelic Pressure Switch Gauge Range 0-750 Pa.

Dwyer A3000-750PA-240VAC Photohelic Pressure Switch/Gauge (0-750 Pa),220/240 VAC Relay Pack

Model: A3000-750PA-240VAC

Bezel and front cover (with set point knobs and zero adjustment screw) removed to expose Photohelic switch/gage set point mechanism. Cover is clear polycarbonate plastic.Gage pointer and light shutter are mounted on helix and balancing counterweight.

Dwyer A3000-750PA-240VAC Series A3000 Photohelic Pressure Switch 0 to 750 Pa

The Dwyer A3000-750PA-240VAC has a range from 0-750 Pa and 220/240 VAC Relay Pack.

Photohelic Switch/Gauges function as versatile,highly repeatable pressure switches combined with a precise pressure gauge employing the time-proven Magnehelic gauge 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 gauge 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. Gauge 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.

Relay-Transformer Features

A plastic housing protects all electronic components. Solid-state and integrated circuit electronics are on glass-epoxy printed circuit boards and self-extinguishing terminal boards.

Dwyer A3000-750PA 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 Accuracy Differential Pressure Monitoring

The A3000-750PA delivers precise monitoring of air and non-corrosive gases with an accuracy of 2% of full scale. Its diaphragm-based design ensures reliable differential pressure readings, supporting applications that require strict control over environmental conditions. With a clear analog display and bold aluminum scale, users can quickly assess pressure values, making it ideal for HVAC, cleanrooms, and process industries.


Flexible Control with Dual Adjustable Switches

Equipped with two independently adjustable SPDT set points, the A3000-750PA allows users to automate responses to fluctuating pressure conditions. These switches enhance safety and efficiency by activating or deactivating external equipment based on preset pressure thresholds. Support for both manual and automatic reset further boosts operational flexibility and system integrity.


Industrial Durability and Easy Integration

Engineered for longevity, this pressure switch gauge features a flame-retardant ABS enclosure, clear acrylic cover, and silicone rubber seals. IP54 protection on the front panel guards against dust and splashes, while the panel mount with provided bracket ensures secure installation. Its compatibility with standard 120/240 VAC power supplies enables straightforward integration into many industrial and commercial systems.