Photohelic® switch/gages series AT3-A3000 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 also available. Two phototransistor actuated, DPDT relays are included for low/high limit control. easy to adjust setpoint indicators are controlled by knobs located on the gage face (accessible opening case after de-enegizing instrument). Individual setpoint deadband is one pointer width – less than 1% of full scale. Setpoints 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. Several ranges available (see standard ranges table).
Service: air and compatible clean and dry gases.
Wetted parts: consult factory.
Photohelic®: from -6.67 a 48.9°C (20 to 120°F).
Option “LT” low temperature to -20°F (-28.8°C) see also case temperature limits.
Case: from -60 to 60°C (see also above, Photohelic® temperature limits).
Accuracy: ±2% f.s. at 70°F (21.1°C)
±3% on -0
±4% on -00 models
Pressure limits: -20” Hg to 25 psig (-0.677 bar to 1.72 bar).
MP option; 35 psig (2.41 bar)
HP option; 80 psig (5.52 bar).
A36003S – A36010S; 150 psig (10.34 bar).
Dial size: 4” (101.6 mm).
Mounting orientation: Diaphragm in vertical position.
Housing material: alluminium (optional stainless steel).
Finishing: texture epoxy coat RAL7038 (only aluminium housings).
Process connections: 1/8” female NPT brass (stainless steel optional). In case of acetylene presence it is compulsory to use stainless steel.
Electrical wiring: screw terminals.
Electrical connection: 3 x 1/2” NPT F standard (supplied without cable gland).
Set point adjustment: adjustable knobs on face of Photohelic® available behind cover (follow instructions and safety warnings to open cover).
Dimensions: see drawing below.
Weight: 12,9 Kg ab.
Response time**: f rom f.s. to 0 up to 120 sec. max
(mainly for low ranges models 60, 100 e 125 Pa or equivalentes).
Switch type: each setpoint has 1 form C relay (SPDT).
Repeatability: ±1% of full scale.
Electrical rating: 10A @ 28 Vcc, 10A @ 120, 240 Vca.
Power Requirements: 120 VAC, 50/60 Hz; 240 VAC & 24 VAC power optional.
* Operating ambient temperatura is defined also according to the options and pressure instrument choosed.
** Due to flame arrestor installation.
CAUTION FOR USE ONLY WITH AIR OR COMPATIBLE GASES!
CONTACT FACTORY FOR USE WITH GASES, OTHER THAN AIR AND NITROGEN.