Series A3000 Photohelic® Pressure Switch/Gage

  • Availability:In Stock
  • Brand: Dwyer
  • Product Code: -

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.

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.

Product Applications

  • Air Conditioner Systems
  • Clean Rooms
  • Fume Exhaust Systems

Model & Ordering

Model Number Description
A3000-0 Pressure switch/gage, range 0-.50" w.c.
A3000-00 Pressure switch/gage, range 0-.25" w.c.
A3001 Pressure switch/gage, range 0-1.0" w.c.
A3002 Pressure switch/gage, range 0-2.0" w.c.
A3003 Pressure switch/gage, range 0-3.0" w.c.
A3004 Pressure switch/gage, range 0-4.0" w.c.
A3005 Pressure switch/gage, range 0-5.0" w.c.
A3006 Pressure switch/gage, range 0-6.0" w.c.
A3008 Pressure switch/gage, range 0-8.0" w.c.
A3010 Pressure switch/gage, range 0-10" w.c.
A3015 Pressure switch/gage, range 0-15" w.c.
A3020 Pressure switch/gage, range 0-20" w.c.
A3025 Pressure switch/gage, range 0-25" w.c.
A3030 Pressure switch/gage, range 0-30" w.c.
A3040 Pressure switch/gage, range 0-40" w.c.
A3050 Pressure switch/gage, range 0-50" w.c.
A3060 Pressure switch/gage, range 0-60" w.c.
A3080 Pressure switch/gage, range 0-80" w.c.
A3100  Pressure switch/gage, range 0-100" w.c.
A3150  Pressure switch/gage, range 0-150" w.c.