1. Explosion proof GB3836.2-2010- Explosive atmospheres - Part 2: Equipment protected by an explosion-proof enclosure "d"

Explosion proof sign: Ex d

Explosion proof principle: The explosion-proof type is to enclose all components of the equipment that may ignite explosive gas mixtures in a single shell. The shell can withstand the internal explosion of combustible mixtures that penetrate through any joint surface or structural gap of the shell without damage, and will not cause ignition of an explosive environment formed by one or more gases or vapors outside (see GB 3836.2 standard). Place components that may generate sparks, arcs, and hazardous temperatures into an explosion-proof enclosure, which separates the internal space of the equipment from the surrounding environment. There are gaps in the explosion-proof shell, which may contain explosive gas mixtures due to the breathing and gas permeation effects of electrical equipment. When an explosion occurs, the shell can withstand the generated explosion pressure without damage. At the same time, the structural gaps of the shell can cool the flame, reduce the flame propagation speed or terminate the acceleration chain, preventing flames or dangerous flame products from crossing the explosion-proof gap and igniting the external explosive environment, thus achieving the purpose of explosion-proof.

2. Increased safety explosion-proof GB3836.3-2010- Explosive atmospheres Part 3: Equipment protected by increased safety "e"

Explosion proof sign: Ex e

Explosion proof principle: An increased safety explosion-proof type is an explosion-proof type that takes additional measures to improve the safety level of electrical equipment that will not generate arcs or sparks under normal operating conditions, and prevents the possibility of dangerous temperatures, arcs, and sparks in its internal and external components. It does not include equipment that generates sparks or arcs under normal operating conditions (see GB 3836.3 standard). On electrical equipment structures that do not generate sparks, arcs, or hazardous temperatures during normal operation, measures are taken to reduce or control the working temperature, ensure the reliability of electrical connections, increase insulation effectiveness, and improve the protection level of the casing, in order to reduce the possibility of contamination caused by dirt and moisture entry, reduce the possibility of ignition faults, and improve the safety and reliability of equipment under normal operation and specified fault conditions (such as motor rotor blockage).

3. Intrinsically safe explosion-proof GB3836.4-2010- Explosive atmospheres Part 4: Equipment protected by intrinsic safety type "i"

Explosion proof sign: Ex i

Explosion proof principle: Intrinsically safe explosion-proof type refers to an intrinsically safe circuit in which all circuits inside the equipment are ignited by any electrical sparks or thermal effects generated under standard specified conditions (including normal operation and specified fault conditions) that cannot ignite the specified explosive gas environment. Intrinsic safety type starts with limiting the energy in the circuit, reducing the potential spark energy to below the specified ignition energy of the gas mixture through reliable control of circuit parameters, and limiting the surface heating temperature of wires and components to below the specified ignition temperature of the gas mixture.

4. Positive pressure explosion-proof GB/T 3836.5-2017 Explosive atmospheres Part 5: Equipment protected by positive pressure shell p

Explosion proof sign: Ex p

Explosion proof principle: Fresh air or inert gas at a certain pressure is introduced into the casing of the equipment, preventing surrounding combustible gases from entering the interior of the casing, thereby preventing point source ignition from coming into contact with explosive gases and achieving the goal of preventing explosions.

5. Oil immersed explosion-proof GB/T 3836.6-2017 Electrical equipment for explosive gas environments Part 6: Oil immersed "O"

Explosion proof sign: Ex o

Explosion proof principle: Oil immersed explosion-proof type is to immerse the entire equipment or its components in oil (protective liquid), so as not to ignite explosive gas environments above the oil surface or outside the shell (see GB 3836.6 standard). This is an old explosion-proof technology method mainly used for switchgear. The formed arc and spark are immersed in oil.

6. Sand filled explosion-proof GB/T 3836.7-2017 Electrical equipment for explosive gas environments Part 7: Sand filled "q"

Explosion proof sign: Ex q

Explosion proof principle: Sand filled explosion-proof type is an electrical equipment protection type that fills the outer shell with sand particles or other specified powder materials, so that under specified usage conditions, the electric arc or high temperature generated inside the shell cannot ignite the surrounding explosive gas environment.

7. N-type explosion-proof GB3836.8-2014- Explosive atmospheres Part 8: Equipment protected by "n-type"

Explosion proof sign: Ex n

Explosion proof principle: Type N is an explosion-proof form of electrical equipment. This type of electrical equipment cannot ignite the surrounding explosive environment under normal operation and certain conditions specified in this standard (only referring to the light source failure condition of the lamp).

8. Encapsulation type explosion-proof GB3836.9-2014- Explosive atmospheres Part 9: Equipment protected by encapsulation type "m"

Explosion proof sign: Ex m

Explosion proof principle: Seal the parts of the equipment that may generate sparks or high temperatures in the sealing agent (resin), so that they cannot ignite the surrounding explosive mixture