DWYER A3000 Series, Photohelic Pressure Switch/ Gages

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. GAGE SPECIFICATIONS Service: Air and non-combustible, compatible gases. Wetted Materials: Consult Factory. Accuracy: ± 2% of FS at 70° F ( 21.1° C) . ± 3% on -0 and ± 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) . 36003S – 36010S; 150 psig ( 10.34 bar) . 36020S and higher; 1.2 x full scale pressure. Temperature Limits: 20 to 120° F. ( -6.67 to 48.9° C) Low temperature option available. Process Connections: 1/ 8 " female NPT. Size: 4 " ( 101.6 mm) dial face, 5 " ( 127 mm) O.D. x 8-1/ 4 " ( 209.55 mm) . Weight: 4 lb ( 1.81 kg) . SWITCH SPECIFICATIONS Switch Type: Each setpoint has 2 Form C relays ( DPDT) . Repeatability: ± 1% of FS. Electrical Rating: 10A @ 28 VDC, 10A @ 120, 240 VAC; Electrical Connections: Screw terminals. Use 167° F ( 75° C) copper conductors only. Power Requirements: 120 VAC, 50/ 60 Hz; 240 VAC & 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. NOTE: Optional ( -EXPL) Explosion-proof Enclosure does not possess any agency approvals.