PHOTOHELIC ® PRESSURE SWITCH/GAGE 3-in-1 Indicating Gage, Lo-Limit and Hi-Limit Control DWYER INSTRUMENTS, INC. | dwyer-inst.com38 The Series A3000 Photohelic ® Pressure Switch/Gage functions 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. 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 in (0-6 mm) w.c. up to 30 psi (21 bar). FEATURES/BENEFITS • 3-in-1 instrument allows the reduction of several instruments with one product, saving inventory, installation time and money • Patented design and 1% full-scale dead band provides quick response to pressure changes means no delay in switching and chatter-free operation • A wide range of models that can meet pressure measurement specifications from low to very high APPLICATIONS • Air conditioning systems • Clean rooms • Fume exhaust systems 2-1/2 [63.50] 2-1/16 [52.39] 2 [50.80] 1-1/4 [31.75] (4) 6-32 HOLES EQUALLY SPACED ON A 5-1/8 [130.18] B.C. Ø4-47/64 [120.25] Ø5 [127.00] Ø4 [101.60] FACE 5-1/2 [139.70] O.D. MOUNTING RING 5/8 [15.88] 5/8 [15.88] PANEL MAX 3/16 [4.76] 3-7/8 [98.43] 5-1/8 [130.18] 6-3/8 [161.93] 7-5/8 [193.68] 4-3/8 [111.13] HOUSING REMOVAL 3/4 CONDUIT CONNECTION Ø4-3/4 [120.65] 3-7/8 SQ [98.43] 1/8 FEMALE NPT HIGH PRESSURE CONNECTION 1/8 FEMALE NPT LOW PRESSURE CONNECTION SPECIFICATIONS 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). 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) OD x 8-1/4˝ (209.55 mm). Weight: 4 lb (1.81 kg). SWITCH SPECIFICATIONS Switch Type: Each set point has 2 form C relays (DPDT). Repeatability: ±1% of FS. Electrical Rating: 10 A @ 28 VDC, 10 A @ 120, 240 VAC. Electrical Connections: Screw terminals. Use 167°F (75°C) 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. Differential Pressure Gages/Switches, Dial PRESSURE Set points are instantly adjusted with front knobs SERIES A3000 V ID E O O N L I N E Pressure_2021.indb 387/15/20 8:16 AM39 Note: Special models can be built to OEM customers’ specifications with scales reading in special pressure units like ounces per square inch, inches of mercury, etc. Square Root Scales reading in FPM or SCFM are also available. Custom logos and special graduations can also be included. Contact factory for minimum quantities and pricing. Differential Pressure Gages/Switches, Dial PRESSURE PHOTOHELIC ® PRESSURE SWITCH/GAGE 3-in-1 Indicating Gage, Lo-Limit and Hi-Limit Control Bezel and front cover (with set point knobs and zero adjustment screw) removed to expose Photohelic ® gage set point mechanism. Cover is clear polycarbonate plastic. Gage pointer and light shutter are mounted on helix and balancing counterweight. Shutter passes through slot in optical limit switch to expose phototransistors to integral infrared light source or mask them depending on applied pressure. Light shield effectively protects phototransistors from strong outside light sources yet allows free pointer movement. It also gives interior a clean “finished” look. Optical limit switches are used for reliability and long service life. Attached directly to set pointers, they are individually aligned to assure precise switching accuracy. Semi-Flexible drive shaft connects to set point knobs. Plastic enclosure protects electronic components and electrical connections. Polycarbonate connection or terminal board is self- extinguishing. Glass-epoxy printed circuit boards for durability and performance. Load relays are DPDT with latching feature for maximum application versatility. Electronics are designed to operate on 50/60 Hz, 120 volt current with 10% over or under voltage. Special units for other voltages are available. Switch set pointers show switch settings at all times. Spring loaded friction clutch prevents operator damage of set point mechanism. Zero adjustment screw connects to screw in cover to adjust zero pressure reading. Process Tubing Options: See page 453 (Gage Tubing Accessories) SERIES A3000 DWYER INSTRUMENTS, INC. | dwyer-inst.com ACCESSORIES ModelDescription A-298 A-601 Flat flush mounting bracket Manual reset switch net MODEL CHART ModelRange, in w.c. Zero Center Ranges ModelRange, mm w.c. Zero Center Ranges ModelRange, in w.c.ModelRange, Pa A3000-00 A3000-0 A3001 A3002 A3003 A3004 A3005 A3006 A3008 A3010 A3015 A3020 A3025 A3030 A3040 A3050 A3060 A3080 A3100 A3150 0-.25 0-.50 0-1.0 0-2.0 0-3.0 0-4.0 0-5.0 0-6.0 0-8.0 0-10 0-15 0-20 0-25 0-30 0-40 0-50 0-60 0-80 0-100 0-150 A3300-0 A3301 A3302 A3304 A3310 A3320 A3330 .25-0-.25 .5-0-.5 1-0-1 2-0-2 5-0-5 10-0-10 15-0-15 A3000-6MM A3000-10MM A3000-25MM A3000-50MM A3000-80MM A3000-100MM 0-6 0-10 0-25 0-50 0-80 0-100 A3300-250PA A3300-500PA 125-0-125 250-0-250 ModelRange, kPa A3000-1KPA A3000-1.5KPA A3000-2KPA A3000-3KPA A3000-4KPA A3000-5KPA A3000-8KPA A3000-10KPA A3000-15KPA A3000-20KPA A3000-25KPA A3000-30KPA 0-1 0-1.5 0-2 0-3 0-4 0-5 0-8 0-10 0-15 0-20 0-25 0-30 Zero Center Model Range in w.c. /Air Velocity, F.P.M. A3300-20MM A3300-30MM 10-0-10 15-0-15 ModelRange, Pascals A3000-00AV A3000-0AV A3001AV A3002AV A3010AV 0-.25/300-2000 0-.50/500-2800 0-1.0/500-4000 0-2.0/1000-5600 0-10/2000-12500 A3000-60PA A3000-125PA A3000-250PA A3000-500PA A3000-750PA 0-60 0-125 0-250 0-500 0-750 Pitot tube required Zero Center Ranges ModelRange, kPa A3300-1KPA A3300-3KPA .5-0- .5 1.5-0-1.5 Bi-Directional Range A3000-00N.05-.20 OPTIONS To order add suffix:Description -SRH -SRL -OLS -RMR -TAMP -MP -HP -LT -NIST Single relay activates on increase Single relay activates on decrease OEM model Remote mounted relay Tamper proof knobs Medium pressure High pressure Low temperature (-20°F) NIST traceable calibration certificate Pressure_2021.indb 397/15/20 8:16 AMNext >