An explosion-proof motor is a type of motor that can be used in flammable and explosive places without producing electrical sparks during operation. Explosion-proof motors are mainly used in coal mines, oil and gas, petrochemical and chemical industries. In addition, it is also widely used in textile, metallurgy, city gas, transportation, grain and oil processing, papermaking, medicine and other sectors. As the main power equipment, explosion-proof motors are usually used to drive pumps, fans, compressors and other transmission machinery.
1. Explosion-proof motors are generally used in flammable and explosive occasions. 2. The sealing of the explosion-proof motor junction box is better than that of ordinary motors. 3. The minimum protection level of explosion-proof motors is IP55, while ordinary motors have IPIP23, IP44, IP54, IP55, IP56, so they can be distinguished from the appearance.
The rated voltage, rated current, power and speed of the explosion-proof motor are the same as those marked by ordinary motors. The difference is that the explosion-proof motor has an explosion-proof logo: Ex.

Explosion-proof type

1. Flameproof Ex d2. Sand-filled typeEx q3. Safety Enhanced Ex e4. Sealed Ex m5. Positive pressure type Ex p6.n type Ex n7. Intrinsically safe type E x ia Ex ib8. Special type Ex s9. Oil-immersed type Ex o10. Dust explosion-proof type DIP A DIP B2

Equipment category Electrical equipment for explosive gas atmospheres is divided into:
Class I: Electrical equipment for underground coal mines; Class II: Electrical equipment for other explosive gas environments except coal mines. Class II flameproof type "d" and intrinsically safe type "i" electrical equipment are divided into IIA, IIB, and IIC categories. Electrical equipment for combustible dust environments is divided into: type A dust-tight equipment; Type B dust-tight equipment.

Temperature group

T1~T6 Ignition temperature of combustible gas

 Product classification

According to the principle of explosion-proof, it can be divided into flameproof motor, safety increase motor, positive pressure motor, non-spark motor and dust explosion-proof motor.
According to the supporting main engine, it can be divided into explosion-proof motors for coal mine transportation machines, explosion-proof motors for coal mine winches, explosion-proof motors for rock loaders, explosion-proof motors for local fans in coal mines, explosion-proof motors for valves, explosion-proof motors for fans, explosion-proof motors for ships, explosion-proof motors for lifting metallurgy, and brushless excitation synchronous motors for hydrogenation devices. In addition, it can also be divided according to rated voltage, efficiency and other technical indicators, such as high-voltage explosion-proof motors, high-efficiency explosion-proof motors, high-speed differential rate explosion-proof motors and high-starting torque explosion-proof motors.

Product range and its characteristics

1. Explosion-proof motor It uses an explosion-proof shell to isolate the electrical part that may generate sparks, arcs and dangerous temperatures from the surrounding explosive gas mixture.

       However, this housing is not sealed, and the surrounding explosive gas mixture can enter the motor through the gaps between the joints of the various parts of the housing. When it comes into contact with sparks, arcs, dangerous high temperatures and other ignition sources in the shell, the flameproof shell of the motor will not only not be damaged or deformed, but also the explosive flame or hot gas can not ignite the surrounding explosive gas mixture when it comes out through the gap of the joint surface.
The basic series of low-voltage flameproof motor products widely used in our country is the YB series flameproof three-phase asynchronous motor, which is a derivative of the Y series (IP44) three-phase asynchronous motor.
The main models of low-voltage flameproof three-phase asynchronous motor derivative series are: YB series (dIIcT4) (base center height 80-315mm), YBSO series (low power, base center height 63-90mm), YBF series (for fans, base center height is 63-160mm), YB-H series (marine, base center height is 80~280mm), YB series (medium, base center height is 355-450mm), YBK series (for coal mines, The center height of the base is 100-315mm), YB-W, B-TH, YB-WTH series (the center height of the base is 80-315mm), YBDF-WF series (for outdoor anti-corrosion and flameproof electric valves, the center height of the base is 80-315mm), YBDC series (flameproof capacitive starting single-phase asynchronous motor, the center height of the base is 71-100mm), YBZS series of flameproof two-speed three-phase asynchronous motor for lifting, YB series high-voltage flameproof three-phase asynchronous motor ( The center height of the base is 355~450mm, 560-710mm).
2. Increased safety type explosion-proof motor It is a motor structure that will not produce arcs, sparks or dangerous high temperatures under normal operating conditions, and then takes some mechanical, electrical and thermal protection measures to further avoid the danger of arcing, sparks or high temperature under normal or recognized overload conditions, so as to ensure its explosion-proof safety.

 The basic series of low-voltage safety increase type currently used in our country is the YA series safety increase three-phase asynchronous motor, which is a derivative of the Y series (IP44) three-phase asynchronous motor.

The main models of low-voltage ampered motor derivative series are:

YASO series low-power safety-enhancing three-phase asynchronous motor (base center height is 56-90mm), YA-W, YA-WFl series outdoor and indoor anti-corrosion and safety enhancement three-phase asynchronous motor (base center height is 80-280mm). The YA2 series has a total of 15 chassis numbers (the center height of the chassis is 63-355mm), and the power range is 0.12-400kW. The high-voltage (6kV) three-phase asynchronous motor series are: YA355-450, power 160-450kW; YA560-900, power 500-1800kW; YAm355-630 water cooling, power 220-2500kw; YAKK355~630 air-air cooling, power 185-2000kW. TAKW4000—20/2600, 4000kW increased safety brushless excitation synchronous motor.

 3. Positive pressure explosion-proof motor is a kind of positive pressure electrical equipment. Its structural features are:

(1) It is equipped with a complete ventilation system, and there are no structural dead corners inside the motor that may affect the ventilation. (2) The shell and pipe are made of non-combustible materials and have sufficient mechanical strength. (3) The positive pressure in the shell and main pipe is maintained sufficiently relative to the outside atmosphere. (4) The motor must have safety protection devices (such as time relays and flow monitors) to ensure sufficient air exchange, and must also have automatic protection or alarm devices for underpressure in the shell. (5) The quick-opening door or cover on the shell must have a device that interlocks with the power supply. At present, our country does not have a unified positive pressure motor series products.

 4. Non-sparking explosion-proof motor refers to a motor that will not ignite the surrounding explosive mixture under normal operating conditions and generally will not cause ignition failure.
Compared with the safety enhancement motor, the design requirements of the safety enhancement motor are the same as those of the safety enhancement motor, except for the insulation dielectric strength test voltage, winding temperature rise, TE (the time from the start of the starting current to the rise to the limit temperature of the AC winding after reaching the rated operating final temperature at the maximum ambient temperature), and the starting current ratio are not as special as the safety enhancement type.
YW series non-sparking motor products (base center height is 80~315mm). The explosion-proof mark is nIIT3, which is suitable for Zone 2 places in the factory containing flammable gases or explosive mixtures formed by vapor and air in the temperature group T1-T3. The rated frequency is 50Hz, the rated voltage is 380, 660, 380/660V, the motor adopts F insulation, but according to the temperature rise limit of the stator winding according to the B level, it has a large temperature rise margin and high safety and reliability, and the power is 0.55~200kW.

5. Dust explosion-proof motor refers to a motor whose shell is designed and manufactured according to the specified conditions, which can prevent dust from entering the motor shell or cannot completely prevent dust from entering, but its entry volume does not hinder the safe operation of the motor, and the accumulation of internal dust is not easy to cause ignition hazard, and will not cause the explosion of the surrounding explosive dust mixture when used.

It is characterized by:

(1) The shell has a high sealing ability to reduce or prevent dust from entering the shell, and even if it does, its ingress will not cause ignition hazard. (2) Control the maximum allowable surface temperature of the enclosure does not exceed the specified temperature group.

At present, it has been used in mechanized equipment of the national grain reserve.

Note: This article is reprinted from the Internet, the copyright belongs to the original author, if there is infringement, please contact the editor to delete.