Division of the most dangerous areas

2022-10-01
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Division of hazardous areas

hazardous areas are divided into different areas according to the frequency and duration of explosive environment. The gas field is divided into three areas: Zone 0, zone 1 and zone 2; Dust sites are divided into three areas: zone 20, zone 21 and zone 22. Combustible gas, steam and mist gas place zone 0: places where explosive mixtures in explosive environment occur continuously or exist for a long time in the form of gas, steam or mist. Electrical equipment used in Zone 0 must be calibrated in accordance with en50284 and IEC д Class, type (gas) electrical equipment shall be designed, tested and identified according to relevant regulations. Zone 1: during normal operation, I may tell them that I regret the presence of explosive mixtures in the form of gas, steam or mist in explosive environments. Zone 1 is a typical application place for explosion-proof electrical equipment. Standard en50014 ~ en50020, en single rod double acting piston cylinder applies experimental force 50039 and IEC, -1, -2- 7, -11, -18, -25 stipulate the electrical equipment used in zone 1. Zone 2: during normal operation, explosive mixture in the form of gas, steam or mist is unlikely to appear in explosive environment. If it appears, it only happens occasionally and exists for a short time. Generally, "short time" refers to the duration of no more than 2 hours. Standards en50021 and IEC have made corresponding provisions on the electrical equipment used in zone 2 that may affect the working effectiveness of the machine, and must also meet the general requirements of insulation resistance, impact energy and dissipation power. Zone 20 in dust area: the en standard has made corresponding provisions on the structure and design of the shell of electrical equipment used in zone 20. IEC has made supplementary requirements for electrical equipment used in zone 20, including intrinsically safe explosion-proof and other aspects. Application Category 1 (dust) electrical equipment in zone 20. Zone 21: mills, coal, grain warehouses and packaging production lines and their surroundings are typical zone 21 places. In zone 21, explosive dust mixtures may be formed due to dust leakage and other reasons. In addition, dust accumulation on the surface of electrical equipment is also a hidden danger of factory safety production. The experimental system can load 70% or 80% of the nominal maximum force of the steel strand within 3 (5) minutes according to the standard requirements, which should be paid enough attention. Explosion proof electrical equipment of category 2 (dust) must be used in zone 21. Zone 22: places where explosive dust mixtures are unlikely to occur during normal operation and are only possible under fault conditions. Explosion proof electrical equipment of Category 3 (dust) must be used in zone 22. If the dust in explosive environment is conductive dust, explosion-proof electrical equipment of category 2 (dust) must be used according to the provisions of en. Factors related to the classification of hazardous locations:

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