It is understood that most people only know that explosion-proof motors are mainly used in inflammable and explosive places, such as inflammable and explosive chemical plants, flour processing plants, wine making, oil fields and so on. But do not know how to choose explosion-proof motor, today xiaobian bring explosion-proof motor knowledge

Product categories

According to the explosion-proof principle

It can be divided into flameproof motor, increasing safety motor, positive pressure motor, spark-free motor and dust explosion-proof motor.

According to the supporting host points

It can be divided into explosion-proof motor for coal conveyor, explosion-proof motor for coal winch, explosion-proof motor for rock loader, explosion-proof motor for local fan in coal mine, explosion-proof motor for valve, explosion-proof motor for fan, Marine explosion-proof motor, explosion-proof motor for hoisting metallurgy and brushless excitation synchronous motor for supporting hydrogenation unit. In addition, can also be divided according to rated voltage, efficiency and other technical indicators, such as high voltage explosion-proof motor, high efficiency explosion-proof motor, high slip explosion-proof motor and high starting torque explosion-proof motor.

Product series and characteristics

1. It uses a flameproof enclosure to separate the electrical parts that may produce sparks, arcs and dangerous temperatures from the surrounding explosive gas mixture. However, the housing is not sealed, and the surrounding explosive gas mixture can enter the motor through the gap between the joint surface of each part of the housing. When contact with spark, arc, dangerous high temperature and other ignition sources in the shell may explode, then the flameproof shell of the motor will not be damaged or deformed, but also the explosive flame or hot gas through the joint surface gap, can not ignite the explosive gas mixture around.

The basic series of low-voltage flameproof motor products widely used in China is YB series flameproof three-phase asynchronous motor, which is the derivative of Y series (IP44) three-phase asynchronous motor. Explosion-proof performance conforms to the provisions of GB3836.1-83 "General Requirements for explosion-proof Electrical Equipment for Explosive Environment" and GB3836.2-83 "Explosion-proof electrical Equipment for Explosive Environment flameproof Electrical Equipment" D "; The motor power range is o.55 -- 200kW, and the corresponding frame size range is the height of the frame center is 80 -- 315nun; The explosion-proof marks are dI, dIIAT4, dIIBT4, respectively, suitable for underground coal mine fixed equipment or factory IIA, IIB class, temperature group for T1-T4 group of combustible gas or steam and air explosive mixture of the place; The main body shell protection grade is IP44, can also be made into IP%4, the junction box protection grade is IP54; Rated frequency is 50Hz, rated voltage is 380, 1660, 1140, 380/660, 660/140V; The insulation grade of the motor is F, but the temperature rise of the stator winding is assessed according to B, which has a large temperature rise margin.

Low voltage flameproof three-phase induction motor derived series of main models are: YB series (dIIcT4)(base center height of 80-315mm), YBSO series (small power, base center height of 63-90mm), YBF series (fan, base center height of 63-160mm), YB -- H series (Marine, base center height of 80-280mm), YB series (medium, The center height of the machine base is 355 -- 450mm), YBK series (for coal mine, the center height of the machine base is 100 -- 315mm), YB -- W, B -- TH, YB -- WTH series (the center height of the machine base is 80 -- 315mm), YBDF -- WF series (for outdoor anti-corrosion and flameproof electric valve, The center height of the frame is 80-315mm) and YBDC series (flameproof capacitor starting single-phase asynchronous motor, the center height of the frame is 71-100mm) and YBZS series of reusable flameproof two-speed three-phase asynchronous motor. In addition, there are YB series of high pressure flameproof three-phase asynchronous motor (the center height of the frame is 355~450mm, 560-710mm).

YB2 series jointly designed by the industry has passed the national identification at the end of 14, and will gradually replace YB series to become the basic series of flameproof three-phase asynchronous motors in China. The YB2 series has a total of 15 frame sizes (center height of the frame is 63, 355nmm), and the power range is o. 12 -- 315kW. Its main characteristics are:

(1) The corresponding relationship of power grade, installation size and speed is consistent with DIN42673. At the same time, considering the inheritance and interchangeability of YB series and Y2 series, necessary adjustment is made to make it more effective and applicable.

(2) The whole series adopts grade F insulation, and the temperature rise is assessed according to grade B.

(3) The noise limit is lower than that of YB series, close to the level I noise of YB series, and the vibration limit is similar to that of YB series.

(4) The protection level of the shell is improved to IP55.

(5) Low noise deep groove ball bearings are selected for the whole series, and oil injection and discharge devices are set for motors with the center height of the frame above 180mm.

(6) The motor radiator has two kinds of parallel horizontal distribution and radiation distribution, mainly parallel horizontal distribution.

(7) The main performance indexes reach the international advanced level in the early 1990s.

2. Increase safety type motor it is under normal operating conditions will not produce arc, spark or dangerous high temperature motor structure, and then take some mechanical, electrical and thermal protection measures, so as to further avoid the normal or recognized overload conditions of arc, spark or high temperature danger, so as to ensure its explosion-proof safety.

The basic series of low-voltage increasing safety type used in China is YA series increasing safety type three-phase asynchronous motor, which is the derivative of Y series (IP44) three-phase asynchronous motor. Explosion-proof performance conforms to gb3836.1-83 "Explosion-proof electrical Equipment for Explosive Environment general Requirements" and GB3836.3-83 "explosion-proof electrical Equipment for Explosive Environment increased safety type electrical equipment" E "; The power range is o. 55~90kW, and the center height of the corresponding frame is 80-280mm; The explosion-proof marks are eIITl, eIIT2 and eIIT3, respectively, which are suitable for the places with tL-T3 explosive mixture and slightly corrosive medium in the factory. The protection grade of the main body shell is IP54, and the protection grade of the junction box is IP55; Rated frequency is 50Hz, rated voltage is 380V; Motor uses F class insulation.

The main models of low-voltage increasing safety motor derived series are: YASO series low-power increasing safety three-phase asynchronous motor (center height of the frame is 56 -- 90mm), Ya-W, Ya-WFL series outdoor, indoor anti-corrosion increasing safety three-phase asynchronous motor (center height of the frame is 80 -- 280mm).

At present, the industry joint design work of YA2 and series has been completed, and trial production is being organized to replace YA series. YA2 whole series has 15 frame sizes (height of frame center is 63-355mm), power range is 0.12-400KW, which will make our country's increased safety motor reach the international advanced level of similar products in the 1980s.

High voltage (6kV) increased safety three-phase asynchronous motor series: YA355-450, power 160-450kW; Ya560-900, power 500-1800KW; Yam355-630 water-cooled, power 220-2500KW; YAKK355~630 air-air cooled, power 185 ~ 2000kW. The takw4000-20/2600 and 4000kW brushless excitation synchronous motors with increased safety produced in 1999 are new explosion-proof motors developed to meet the needs of petroleum deep processing and hydrogenation units in oil refineries. Its characteristics are:

(1) Meet the requirements of increased safety explosion-proof motor, adopt a series of reliable measures to prevent spark, arc and dangerous high temperature, can safely operate in zone 2 explosion danger place.

(2) Brushless excitation is adopted, rotating rectifier plate and static excitation cabinet are set, and the excitation control system is reliable; Positive polarity slip excitation is accurate, no impact; The excitation system has reliable out-of-step protection and strong restep ability. The circuit design is reasonable, the discharge resistance does not heat in the work; Wide range of excitation current regulation.

(3) Synchronous machine, AC exciter and rotary rectifier coaxial. The rectifier plate is located between the main motor and the exciter, or outside the bearing seat.

(4) The protection grade of the shell is IP54.

(5) Grade F insulation is adopted, and temperature rise is assessed according to grade B.

(6) Change the traditional water cooling to water cooling, that is, the water cooler is placed on the upper part of the motor.

(7) Set the moisture-proof heater with increased safety, which is fixed in the cover at the bottom of the motor for heating and moisture-proof when stopping.

(8) Choose high-quality raw materials, electrical and mechanical calculation with a large margin, can meet the operating reliability and increased safety type of motor temperature requirements.

(9) Set up perfect monitoring measures; The main junction box is provided with an increased safety type self-balancing current transformer for differential protection; Stator windings buried work and spare platinum thermal resistance, the indexing number is Pt100; A water leakage monitoring instrument to monitor the leakage of the water cooler; Both ends of the seat type sliding bearings are respectively equipped with field temperature display instrument and remote signal terminal.

3. Positive pressure motor is a kind of positive pressure electrical equipment.

Its structural characteristics are:

(1) Equipped with a complete set of ventilation system, there is no structural dead Angle inside the motor that may affect ventilation.

(2) Housing and piping are made of non-combustible material and have sufficient mechanical strength.

(3) Maintain sufficient positive pressure in the shell and main pipe relative to the outside atmosphere.

(4) The motor must be equipped with safety protection devices (such as time relay and flow monitor) to ensure sufficient air change, and there must be automatic protection or alarm devices for pressure underpressure in the shell.

(5) The quick opening or cover on the housing shall have an interlocking device with the power supply.

At present, there is no unified positive pressure motor series products in China.

4. Sparkless motor refers to the motor that will not ignite the surrounding explosive mixture under normal operating conditions, and generally will not occur ignition failure. Compared with increased safety type motor, in addition to the insulation dielectric strength test voltage, winding temperature rise, te (at ambient temperature reached highest rated running after the final temperature of ac winding, since started by starting current meter to temperature rise to the limit of time) and starting current than not like increased safety type has special provisions, and other aspects to add safety type motor design requirements.

Spark - free motor conforms to gb3836.1-83 and GB3836.8-87 "explosion-proof electrical equipment for explosive Environment spark - free electrical equipment" N ". The design pays attention to the sealing measures of the motor, the protection grade of the main body shell is IP54, IP55, and the junction box is IP55. For motors rated above 660V, connections for space heaters or other auxiliary devices shall be placed in separate junction boxes.

At present, domestic has developed and produced YW series spark - free motor products (center height of the frame is 80~315mm). The explosion-proof mark is nIIT3, which is suitable for the site in zone 2 where the factory contains the combustible gas or the explosive mixture formed by steam and air in the temperature group T1-T3. The rated frequency is 50Hz, and the rated voltage is 380, 660, 380/660V. The motor is F insulated, but the temperature rise limit of the stator windings is assessed according to class B. 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 the housing design and manufacture according to the prescribed conditions, can prevent the dust into the motor shell or cannot completely prevent dust to enter, but it into the quantity does not interfere with the safe operation of the motor, and internal dust accumulation is not easy to produce fire danger, when using, also won't cause around with explosive dust mixture explosion of the motor. Its characteristics are:

(1) The shell has a high sealing, in order to reduce or prevent dust into the shell, even if entering, the amount of entry will not cause the formation of ignition danger.

(2) The maximum permissible temperature of the control shell surface shall not exceed the specified temperature group.

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

The national standard of dust explosion-proof electrical equipment is GBL2476.1-90 "Explosion-proof electrical equipment for explosive dust environment".