Explosion-proof electrical equipment type selection - Solutions - Huaqiang Electronic Network

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Before selecting electrical equipment for use in explosive hazardous locations, the following should be clearly defined:
1. The type of environment in which a hazardous area is burned is a burning gas environment or a burning dust environment. The explosion-proof structural requirements of electrical equipment for different explosive media are different. We usually say that explosion-proof equipment is mostly used in explosive gas environments, such as dIIBT4, dIICT6, etc., and electrical equipment used in explosive dust environment should be dust-proof structure, marked as DP, mainly used for flammability. The 11-zone environment or dust-tight structure of conductive dust and combustible fiber is marked as DT, and is mainly used in the explosive dust 10 area environment and other explosive dust 11 area environment.
2. Explosion levels of explosive gas mixtures in the environment, namely IIA, IIB, IIC. This is the pole that corresponds to the maximum test safety clearance and minimum ignition current ratio of the equipment. The grades vary depending on the medium in which the explosive gas is generated, such as propane IIA, ethylene IIB, acetylene, and hydrogen IIC. From IIA to IIC, the explosion-proof requirements of the explosion-proof electrical equipment are gradually increased with the step-by-step reduction of the maximum test safety clearance and the minimum ignition current ratio.
3. The group or ignition temperature of the explosive gas mixture in the environment. This is the lowest temperature at which a hot surface is ignited under the specified conditions of a gas of a flammable substance or a mixture of steam and air. As the ignition temperature decreases from the group T1 to T6, the explosion-proof requirements of the electrical equipment are gradually increased.
4. Selection requirements for explosion-proof electrical equipment in the surrounding environment. Such as chemical, mechanical, thermal, mold and other environmental conditions in the surrounding environment, should be considered in the selection of explosion-proof electrical equipment.
After considering the above basic requirements, you can choose explosion-proof electrical products that meet the requirements. (Source: http://) For some electrical equipment that must be placed in an explosion hazardous area, and its explosion-proof requirements can not meet the requirements of the site, positive pressure ventilation measures can be used to achieve explosion-proof Requirements. The specific requirements for positive pressure ventilation are detailed in the national standard G50058-92.
According to the national standard "General requirements for explosion-proof electrical equipment for explosive atmospheres", the various types of explosion-proof types are as follows:
Flameproof type d
Increased safety type e
Intrinsically safe ia, ib
Positive pressure type p
Oil-filled o
Sand filling type q
Non-sparking type n
Special type s
Electrical equipment is divided into two categories: Class I is electrical equipment used in underground coal mines;
Class II is factory electrical equipment such as factory explosion-proof type B T4: dIIBT4;
A group of increased safety type B T3 for the factory: eIIBT3.