What is explosion-proof electrical equipment?

What is explosion-proof electrical equipment?

The professional definition of explosion-proof electrical equipment refers to electrical equipment designed and manufactured according to specified conditions (explosion-proof type) that will not cause explosions in the surrounding explosive mixture (explosion-hazardous places). In short, it refers to an electrical equipment used in explosive environments.

The so-called equipment used in explosive environments refers to the general term for electrical explosion-proof equipment and non-electrical explosion-proof equipment that are used alone or in combination in explosive environments and can prevent explosions caused by their own potential ignition sources.

What are the categories of explosion-proof electrical equipment?

According to the applicable explosive environment, it is divided into Class I, Class II and Class III. That is, the categories of explosion-proof electrical equipment are divided into: Class I: electrical equipment for coal mines, explosion-proof for mines; Class II: electrical equipment for other explosive gas environments except coal mines, explosion-proof for gas plants; Class III: electrical equipment for explosive dust environments except coal mines, explosion-proof for dust plants.

Class II equipment categories are further divided into: Class IIA: propane, natural gas, etc.; Class IIB: ethylene, ethanol, etc.; Class IIC: hydrogen, acetylene, etc.

Class III equipment is further divided into: Class IIIA: flammable flying fluff (such as: man-made fibers, cotton, hemp, etc.); Class IIIB: non-conductive dust (ρ＞1kΩ·m), Class IIIC: conductive dust (ρ≤1kΩ·m).

3. What is the equipment protection level EPL?

The protection level of the equipment is based on the possibility of the equipment becoming an ignition source and the different characteristics of the explosive gas environment, explosive dust environment and coal mine methane explosive environment.

Equipment protection level EPL-gas:

Ga: Equipment for explosive gas environment, with a "very high" protection level, is not an ignition source under normal operation, expected faults or rare faults.

Gb: Equipment for explosive gas environment, with a "high" protection level, is not an ignition source under normal operation or expected fault conditions.

Gc: Equipment for explosive gas environment, with a "general" protection level, is not an ignition source in normal operation, and some additional protection measures can also be taken to ensure that effective ignition will not be formed when the ignition source is expected to appear frequently (such as the failure of the lamp).

Equipment Protection Level EPL-Dust:

Da: Equipment for explosive dust environments, with a "very high" protection level, is not an ignition source under normal operation, expected faults or rare faults.

Db: Equipment for explosive dust environments, with a "high" protection level, is not an ignition source under normal operation or expected fault conditions.

Dc: Equipment for explosive dust environments, with a "general" protection level, is not an ignition source in normal operation, and some additional protection measures can also be taken to ensure that effective ignition will not be formed when the ignition source is expected to appear frequently (such as the failure of lamps).

4. What is the classification of explosion-proof electrical use areas? In the gas use area: divided into Zone 0, Zone 1, and Zone 2.

Zone 0: Places where explosive gas environments appear continuously or exist for a long time;

Zone 1: Places where explosive gas environments may appear during normal operation;

Zone 2: Places where explosive gas environments are unlikely to appear during normal operation, and if they appear, they occur occasionally and only exist for a short time.

In the use area of dust: divided into Zone 20, Zone 21, and Zone 22.

Zone 20: A place where combustible dust clouds in the air exist continuously or for a long time or frequently for a short time in an explosive dust environment;

Zone 21: A place where combustible dust clouds in the air are likely to exist in an explosive dust environment accidentally during normal operation;

Zone 22: A place where combustible dust clouds in the air are unlikely to exist in an explosive dust environment during normal operation, and if they exist, they are only short-lived.