Introduction to explosion-proof electrical knowledge

1.Explosion proof electrical equipment

It refers to electrical equipment designed and manufactured in accordance with national standards and relevant explosion-proof technical standards, and used in explosive environments under specified conditions without causing surrounding explosions.

2.Explosion proof type

Various specific measures taken on electrical equipment to prevent ignition of the surrounding explosive environment.

In explosive gas environments, the explosion-proof types in the explosion-proof signs are divided into explosion-proof shell type "d", increased safety type "e", intrinsic safety type "i", positive pressure shell type "p", oil immersed type "o", sand filled type "q", spark free type "n", pouring type "m", special type, etc.

2.1 Explosion proof shell type "d"

The explosion-proof safety performance of explosion-proof enclosure type electrical equipment is mainly ensured by the "explosion-proof enclosure". "Explosion proof enclosure" allows explosive gas mixtures entering the interior to undergo combustion and explosion within the enclosure, but does not allow the explosion to spread out of the enclosure and ignite the surrounding explosive gas mixture.

2.2 Enhanced safety "e"

The explosion-proof safety performance of increased safety electrical equipment mainly involves taking some structural measures and safety requirements for electrical equipment to further improve their safety and reliability, so that it cannot become a source of ignition for combustible gases.

2.3 Intrinsic safety type "i"

The explosion-proof safety performance of intrinsically safe electrical equipment is mainly achieved by limiting circuit energy. In this type of electrical equipment, even electrical discharge and thermal effects caused by faults such as short circuits, open circuits, insulation breakdown, etc. cannot ignite explosive gas mixtures.

2.4 Positive pressure shell type "p"

The explosion-proof safety performance of positive pressure shell type electrical equipment relies on filling the electrical equipment with a protective gas with a certain pressure, so that the electrical components that may produce sparks, arcs, and dangerous temperatures inside the equipment are in the protective gas. In this way, these components will not be at risk of igniting explosive gas mixtures.

2.5 Oil immersed type "o"

The explosion-proof safety performance of oil immersed electrical equipment is achieved by immersing the components inside the electrical equipment into protective oil to avoid exposure to combustible gases.

2.6 Sand filled mold "q"

The explosion-proof safety performance of sand filled electrical equipment is achieved by fixing the electrical components of the equipment in appropriate positions inside the equipment casing, and completely burying these components with filling materials to prevent them from igniting combustible gas air mixtures outside.

2.7 Spark free type "n"

The protection methods of the "n" type explosion-proof type are very complex and classified very finely. The overall purpose of "n" type electrical equipment is to ensure that it should not generate operational sparks, arcs, or hazardous temperatures when operating under normal operating conditions and specified abnormal conditions. Even if sparks, arcs, or hazardous temperatures are generated, they cannot ignite explosive gases around them under their own protective measures.

2.8 Pouring and sealing type "m"

The explosion-proof safety performance of sealed electrical equipment is to use sealing compounds to seal the protected electrical components, preventing them from coming into contact with the surrounding combustible gas, thereby avoiding ignition of the surrounding explosive gas environment.