Explosion-proof electrical contacts

Explosion pressure gauge system according to GB3836.1 83 "explosive environment with explosion-proof electrical equipment General requirements" and GB3836.2 83 "electrical equipment for explosive atmospheres flameproof electrical equipment" d "" the relevant provisions of the relevant standards for the design and manufactured by the inspection agency designated by the State for approval drawings and technical documents. Introduction meter Explosion flameproof category Ⅱ class B grade T4 group, the symbol for Ex-proof electrical contacts dⅡBT4. Instrument suitable in places at risk of explosion is used to measure non-crystalline, non-explosive mixture solidified or various non-explosive media pressure. Instrument performance by having a corresponding explosion or take appropriate safety measures electrical devices (such as relays and contactors, etc.) supporting the use of the controlled system able to achieve automatic control and letter (warning) purposes. Technical indicators Accuracy: 1.5 scale range: 0 to 0.16; 0 to 0.25; 0 to 0.4; 0-0.6; 0-1; 0 to 1.6; 0 to 2.5; 0-4; 0-6; 0-10 ; 0 to 16; 0 to 25; 0-40; 0-60; -0.1 to 0.06; -0.1 to 0.15; -0.1 to 0.3; -0.1 to 0.5; -0.1 to 0.9; -0.1 to 1.5; -0.1 ~ 2.4MPa -0.2-3.6MPA Control: upper and lower contact switch Postponed maximum working voltage: DC 220V or AC 380V; Contact power: 10VA working position: vertical installation Environmental conditions: -10 ~ 50 ℃, relative humidity less than 80%, and the explosive mixture should belong to the following ⅡB level T4 group, working vibration and pulsation sharp response meter measured media contacts reliable action has no effect. Temperature effects: show the value of not more than 0.4% / 10 ℃, the set point of not more than 0.6% / 10 ℃ (temperature deviation from 20 ± 5 ℃). Dielectric Strength: 50Hz sinusoidal AC 2000V lasted one minute Weight: 6kg · flameproof joint types and basic parameters of the housing volume V (L)> 0.5 flat cylindrical type joints (movable portion) flameproof joint minimum effective Length Lmm 15 screw through hole edge to the flameproof joint minimum effective length L1 8 flameproof joint surface roughness Ra maximum gap or difference in diameter Wmm 0.15 flameproof joint 3.2 1.6 Note: flameproof joint effective length and space Examples can be found in the width of the flameproof enclosure structure diagram. · Flameproof enclosure and lead pressure system and other parts and materials Part Name Material grade or material grade name part name or the name of the drive casing cover outlet box ZL102 (or ZL-102, ZL-101) thin gasket joint 20 L3 sleeve QAJ9-2 Bourdon tube 3J53 plexiglass viewing window NOTE: Material impact strength, the viewing window is not less than 4J. Viewing window once the damage is not allowed to use. Structure principle Instrument from the flameproof enclosure, measuring systems, electric contact group, regulator and outlet boxes and other components. Instrument flameproof flameproof enclosure with good performance, so in the normal course of their work because of the spark or arc, in addition to withstand the explosion pressure inside the casing of explosive gas mixtures in the event of cause explosion outside, and can effectively The resulting heat to prevent the spread of outward success, but only slowly spread along the outside of the small gap at the flameproof joints inside the casing. At this time, instant temperature spread outside of the housing has been reduced to an explosive gas mixture ignition temperature, it will not lead to the booster. The working principle of the instrument is based on the detection element (Bourdon tube measuring system) is elastically deformed by mechanical transmission so that electrical contacts to drive the group to produce the corresponding action contacts (closed or open) so that the control pressure system circuit can be turned on or off, in order to achieve the purpose of automatic control alarm and field instruction.