Sometimes clients come to inquireZhongnuo TestingHe has products that require intrinsic safety certification. What is the difference between this and explosion-proof certification?
This involves the issue of various types of explosion-proof certification.Actually, intrinsic safety is just one type of explosion-proof protection.
Explosion proof certification is the process of determining whether equipment meets the requirements of explosion-proof standards, conducting type tests and routine tests for adaptation, and issuing relevant certificates of conformity. The certificate can be for Ex devices or Ex components. The explosion-proof certification here applies to the certification of various electrical and non electrical equipment used in places with explosive gases and combustible dust.
But there are various types of explosion-proof equipment on the market, with thousands of different structures, uses, installation and usage methodsExplosion proof certificationIs the same explosion-proof protection type adopted?
This is definitely unrealistic.
We also see lightweight handheld devices in the market, as well as large devices that are several meters high. They use different types of explosion-proof protection, such as single intrinsic safety type, explosion-proof and intrinsic safety type, composite explosion-proof type (combining two or more explosion-proof types), etc.
At present, there are mainly the following types of protection for various explosion-proof equipment on the market:
1. Explosion proof type "d"，Put the equipment into an explosion-proof enclosure to achieve the purpose of explosion prevention. When it explodes, the shell can withstand the generated explosion pressure without damage, and the gap between the shell structure can cool the flame, reduce the flame propagation speed, or terminate the acceleration chain, so that the flame or dangerous flame products cannot penetrate the explosion-proof gap and ignite the external explosive environment, thereby achieving the purpose of explosion-proof. Explosion proof standard reference GB3836.2
2. Increased safety type "e"，On electrical equipment structures that do not generate sparks, arcs, or hazardous temperatures during normal operation, measures are taken to reduce or control operating temperatures, ensure the reliability of electrical connections, increase insulation effectiveness, and improve enclosure protection levels to reduce the possibility of contamination caused by dirtZhongnuo TestingMeasures such as preventing moisture from entering can 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). Explosion proof standard reference GB3836.3
3. Intrinsic safety type 'i',The intrinsic safety explosion-proof type is an intrinsic safety circuit in which all circuits inside the equipment are generated under standard specified conditions (including normal operation and specified fault conditions), and any electric sparks or thermal effects cannot ignite the specified explosive gas environment. Intrinsically safe 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. Explosion proof standard reference GB3836.4
4. ExactlyPressure type 'p',Inject a certain pressure of fresh air or inert gas into the casing of the device to prevent surrounding flammable 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. Explosion proof standard reference GB3836.5
5. Liquid immersion type "o",Liquid immersion explosion-proof type refers to immersing the entire equipment or its components in oil (protective liquid) to prevent ignition of explosive gas environments above the oil level or outside the casing. This is an old explosion-proof technology method mainly used for switchgear. The formed arc and spark are immersed in oil. Explosion proof standard reference GB3836.6
6. Fill sand mold 'q',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 arc or high temperature generated inside the shell cannot ignite the surrounding explosive gas environment. Explosion proof standard reference GB3836.7
7. N-type,Type N is an explosion-proof form of electrical equipment, which cannot ignite the surrounding explosive environment under normal operation and certain conditions specified in this standard (only referring to light source failure conditions of lamps).
The non sparking type originally only referred to electrical equipment that does not generate sparks or arcs during normal operation, such as AC asynchronous motors. Based on this, some safety measures are taken, such as using non sparking materials for fan blades, an IP44 or IP54 enclosure protection level, and appropriately increasing electrical clearances and creepage distances. Later, this explosion-proof concept expandedZhongnuo TestingFor electrical products that generate sparks during normal operation, measures such as gas sealing, simple ventilation, or energy limitation should be taken according to their situation to achieve a certain level of safety. Due to the expansion of this explosion-proof type, the term "spark free" is no longer very precise and is now often referred to as the "n" type. Explosion proof standard reference GB3836.8
8Sealed type'm ',Seal the parts of the equipment that may generate sparks or high temperatures in a sealing agent (resin) to prevent them from igniting the surrounding explosive mixture. Explosion proof standard reference GB3836.9
The above is a list of explosion-proof protection types for electrical equipment used in explosive gas environments. Intrinsic safety is only one type of explosion-proof protection, and intrinsic safety certification is only the protection form adopted in explosion-proof certification.
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