What is an explosion-proof motor?

To obtain certification and a nameplate, the candidate motor must meet the testing standards specified by the industry standard UL - 674: Motors and Generators for Hazardous (Classified) Locations. Manufacturers submit the expected operating specifications of the candidate motor, such as RPM, torque, power, and frequency, along with a description of related equipment, such as variable frequency drives (VFDs). UL conducts destructive testing to determine the motor's temperature rise and ensure that the motor complies with UL certification standards.

Development Trends of Explosion-Proof Motors (Petrochemical Explosion-Proof Motors)

(1) The demand for increased safety and spark-free motors is expected to rise. Users in the petrochemical system have recognized the necessity of developing increased safety and spark-free motors in their practical applications. (2) The reliability of explosion-proof motors has increasingly attracted the attention of users in the petrochemical system. As petrochemical enterprises develop towards larger installations and continuous operations, there is a demand for systems to achieve long operational cycles with little to no maintenance. Therefore, explosion-proof motors have become key equipment to ensure these requirements.

Development Trends of Explosion-Proof Motors (Mining Explosion-Proof Motors)

Developing high-power motors: The maximum installed capacity of coal mining machines in the world has exceeded 1200 kW, with the driving motor power reaching 600 kW. The maximum installed capacity of the scraper conveyor in the corresponding mining area has exceeded 1500 kW, with the driving motor power reaching 725 kW. In China, the maximum power of the driving motor for coal mining machines is 400 kW, and the maximum power of the driving motor for scraper conveyors is 315 kW.

Explosion-proof motor (dust explosion-proof motor)

The motor is designed and manufactured with an outer shell that meets specified conditions, capable of preventing dust from entering the motor housing. Even if it cannot completely stop dust from entering, the amount that does enter does not hinder the safe operation of the motor. Additionally, the accumulation of dust inside does not easily pose a risk of ignition, and its use will not cause an explosion of surrounding explosive dust mixtures.

Explosion-proof motor (spark-free motor)

This refers to a motor that, under normal operating conditions, will not ignite surrounding explosive mixtures and generally will not experience ignition failures. Compared to increased safety motors, except for the insulation dielectric strength test voltage, winding temperature rise, te (the time taken for the AC winding to reach the rated operating final temperature after starting current is applied until it rises to the limit temperature at the highest ambient temperature), and starting current ratio, which do not have special regulations like increased safety motors, other aspects are the same as the design requirements for increased safety motors.

Explosion-proof motor (positive pressure motor)

It is a type of positive pressure electrical equipment. Its structural characteristics are: (1) It is equipped with a complete ventilation system, and there are no structural dead corners inside the motor that could affect ventilation. (2) The shell and ducts are made of non-combustible materials and have sufficient mechanical strength. (3) The shell and main ducts maintain a sufficiently high positive pressure relative to the external atmosphere.

Explosion-proof motor (Increased safety motor)

It is a motor structure that does not produce arcs, sparks, or dangerous high temperatures under normal operating conditions. Additionally, some mechanical, electrical, and thermal protection measures are implemented to further prevent the occurrence of arcs, sparks, or high-temperature hazards under normal or recognized overload conditions, thereby ensuring its explosion-proof safety.

Characteristics of Explosion-Proof Motors

The explosion-proof motor uses an explosion-proof enclosure to separate the electrical components that may produce sparks, arcs, and dangerous temperatures from the surrounding explosive gas mixture. However, this enclosure is not sealed, and the surrounding explosive gas mixture can enter the interior of the motor through the gaps at the joints of the enclosure.

The main types of explosion-proof motors.

It can be divided into explosion-proof motors for coal mine transporters, explosion-proof motors for coal mine winches, explosion-proof motors for rock loading machines, explosion-proof motors for local ventilation fans in coal mines, explosion-proof motors for valves, high-power explosion-proof motors for fans, explosion-proof motors for ships, explosion-proof motors for lifting metallurgy, and enhanced safety brushless excitation synchronous motors for hydrogenation devices, among others. Additionally, it can be categorized based on technical specifications such as rated voltage, efficiency, etc., including high-voltage explosion-proof motors, high-efficiency explosion-proof motors, high slip rate explosion-proof motors, and high starting torque explosion-proof motors.

What is an explosion-proof motor?

Explosion-proof motors are a type of motor that can be used in flammable and explosive environments without generating electrical sparks during operation. They are primarily used in coal mines, oil and gas, petrochemical, and chemical industries. Additionally, explosion-proof motors are widely applied in sectors such as textiles, metallurgy, urban gas, transportation, grain and oil processing, papermaking, and pharmaceuticals.