Classification and selection of explosion-proof control cabinets
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How are explosion-proof control cabinets classified? What types are there usually? Is the common positive pressure explosion-proof effect better, or is it better to use increased safety or explosion-proof? ! :o
There are 9 types of explosion-proof. The most commonly used ones for strong current are explosion-proof type, usually with an explosion-proof shell outside. The commonly used ones for weak current detection instruments are intrinsically safe type.
The form of the explosion-proof control cabinet depends on the area in which the control cabinet is used. Class 1 areas use explosion-proof form, and Class 2 areas can use explosion-proof or positive pressure explosion-proof forms.
Scope of application: 1. Zone 1 and Zone 2 hazardous gas places; 2. Explosive gas or vapor environments of Class ⅡA, ⅡB, ⅡC Group T1-T6; 3. Indoor and outdoor (IP54, IP65) Generally, increased safety type and explosion-proof electric increased safety type electrical equipment will not produce arcs, sparks or high temperatures that may ignite explosive mixtures under normal operating conditions. Structural measures are taken to improve the safety margin to avoid arcs, sparks or high-humidity electrical equipment under normal and approved overload conditions. The mark is "e". Flameproof electrical equipment has an electrical equipment enclosure that can withstand the explosion pressure of the explosive gas mixture inside and prevent the internal explosion from propagating to the explosive mixture around the enclosure. Its mark is "d".
Of course, positive pressure explosion-proof cabinets have the best effect, because during operation, the external air source provides a slightly positive pressure environment in the cabinet to ensure that external dangerous media cannot enter the cabinet at any time. However, the technical requirements are correspondingly high and the cost is also high. When selecting explosion-proof equipment, the selection should be based on the hazardous areas set in the explosion hazard area division map. At the same time, economy must also be considered. Intrinsically safe types or the positive pressure types you mentioned cannot be used everywhere. Wherever the explosion-proof type can be used, try to use it. At the same time, when designing, try to consider locating the control cabinet outside the hazardous area.