SINO Testing Services| 2020-12-22|Return
1、 What is intrinsically safe electrical equipment?
By limiting various parameters of electrical equipment circuits or taking protective measures to limit the spark discharge energy and thermal energy of circuits, the sparks and thermal effects generated during normal operation and specified fault conditions cannot be ignitedZhongnuo TestingThe explosive mixture in the surrounding environment achieves electrical explosion-proof, and the circuit of this electrical equipment itself has explosion-proof performance, which is essentially safe, hence it is called intrinsic safety. Electrical equipment that uses intrinsically safe circuits is called intrinsically safe electrical equipment.
2、 Explosion proof principle of intrinsically safe electrical equipment
Intrinsically safe explosion-proof type refers to all circuits inside the equipment that are subjected to standard specified conditions（Including normal operation and specified fault conditions）Any electrical sparks or thermal effects generated below shall not ignite the specified explosivenessZhongnuo TestingIntrinsic safety circuits in gas environments. 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.
3、 Interpretation of intrinsic safety explosion-proof level
1"Ia"Grade electrical equipment is an intrinsically safe electrical equipment that cannot cause ignition under normal operation and the application of a fault or any combination of two fault conditions; stay"Ia"In a type of circuit, the working current is limited to100mABelow."Ia"Type instruments are suitable for0District1District and2District.
2"Ib"Grade electrical equipment is an intrinsically safe electrical equipment that cannot cause ignition under normal operation and the application of a fault condition. stay"Ib"In a type of circuit, the working current is limited to150mABelow."Ib"Type instruments are suitable for1District and2District.
3"Ic"Grade electrical equipment does not consider fault conditions and is suitable for2District.
4、 The main measures for intrinsic safety explosion-proof:
1. Voltage and current limitations of the circuit;
2. Limitations of capacitance and inductance in circuits;
3. Isolation between intrinsically safe circuits and non intrinsically safe circuits;
4. Requirements for reliable components and components;
5. Regulations on safety barriers;
6. Fault analysis and testing regulations, etc.
5、 Standards applicable to intrinsically safe electrical equipment:
1GB3836.4-2010Electrical equipment for explosive gas environments4Part: Intrinsically Safe"I"Protected equipment
2IEC60079-11-1999Electrical equipment for explosive gas environments11Part: Intrinsically Safe"I"Protected equipment
6、 Characteristics and Scope of Application of Intrinsically Safe Electrical Equipment
Due to the inherent safety of the circuit of intrinsically safe electrical equipment, sparks, arcs, and heat generated will not ignite explosive mixtures in the surrounding environment. Therefore, intrinsically safe electrical equipment does not require a specialized explosion-proof enclosure, which can reduce the volume and weight of the equipment and simplify its structure. At the same time, the transmission lines of intrinsically safe electrical equipment can use both adhesive and bare wires, which can save a lot of cables. Therefore, intrinsically safe electrical equipmentZhongnuo TestingIt is an ideal explosion-proof electrical equipment with the characteristics of safety and reliability, simple structure, small size, light weight, low cost, and convenient manufacturing and maintenance. However, due to the maximum output power of intrinsically safe electrical equipment being25WLeft and right, therefore the scope of use is limited. At present, intrinsically safe electrical equipment is mainly used for communication, monitoring, signal and control systems, as well as instruments and meters.
surface1Intrinsic safety circuit diagram
surface2Intrinsically Safe Components - Zener Safety Barriers
surface3Intrinsic safety system structure diagram
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