Motor common terms

The term Output: refers to the motor can be carried out within the time unit of work, and in accordance with the speed of the motor and the torque to decide. Rated output: motor in the rated voltage, rated frequency can exert its most excellent properties, and continuously produce all kinds of energy output at the same time, such as speed or torque values. Usually motor nameplate on values in the rated output. Asia usually in watts (W) as the unit, Europe and the United States use the horsepower (HP). Rated output (capacity) : rated output power (watts). HP: one of the motor output power unit for HP (Horse power, "HP"), 1 horsepower (HP) = 746 watt (Watts) Rated voltage: when used to allow the input voltage, use more than the rated voltage, the motor usually can still work, but can significantly shorten the service life of the capacitor, and even produce high fever and burned after running for a long time. Use the unit with V (V). torque Starting torque: refers to the motor torque generated at the moment of startup, if motor by a greater wholesalemotor.blogspot.com friction torque Motor vehicle than that suppress load, the motor will not be able to start. Also known as the starting torque. Stop torque: refers to the motor in a certain voltage, under a certain frequency can output the maximum torque, once carries the load beyond the range of torque, motor and then stop. Rated torque: refers to the motor under the rated voltage, rated frequency can produce continuously at rated output torque. Is generated by the torque when the rated speed. speed The rated rotor balancing machine speed: refers to the rated speed, the output of the motor do for motor under the trouble-free use the ideal of running speed. No load speed: refers to the speed of motor with no load condition. The CW or CCW: refers to the running direction of the motor. The CW to see from the output shaft end of the clockwise direction, while it is counterclockwise.

Energy saving conditions

Energy-saving equipment technical conditions To draft This standard by the shandong province economic and trade commission, the bureau of quality and technical supervision of shandong province is put forward. This standard by the shandong energy standardization technical committee to review. motor spare parts This www.dongfeng-motor.com standard drafting unit: shandong province product quality supervision and inspection institute. Main drafter of this standard: Dong Jiang, Carolyn lau, Wang Feng, XinFeng, Lu Jinduo, Gao Jing, John rambo, Chen Hengliang Lin. Standard number: DB37 / T728-2007 The scope of This standard specifies the conditions of use of motor energy saving device, technical requirements, test methods, inspection rule, marks, packaging, transport and storage. This standard applies to rated voltage 660 v and below and rated current under 600 a and motor energy saving devices. Terms and definitions Energy-saving device: 1, the motor used in electric three phase asynchronous motor motor before input, control motor energy saving operation of electrical equipment (not including the inverter). 2, www.facebook.com/guohong.trading power saving rate in the same condition, the same time, the use of motor energy saving devices save electrical energy (kW · h) and not to use motor energy saving devices use electricity (kW · h) ratio, expressed as percentage. Conditions of use 1) : the elevation 1000 meters, and the following; 2) ambient temperature: 0 ℃ ~ + 40 ℃. 3) relative humidity: 90% or less (+ 25 ℃); 4) no serious damage to insulation and corrosion of metal in the air gas, conductive dust and flammable and explosive medium.

The cause of the three-phase asynchronous motor burn machine

The cause of the three-phase asynchronous motor burn machine can be divided into; Load, power supply, electrical insulation, lack of phase Power supply: add load under the condition of rated voltage is too low, current increase, motor overheating. The power supply voltage is too high, burning machine. Or motor open phase running. This kind of situation is less, is easy to determine, mainly the line with traces www.dongfeng-motor.com of burning. Load) : more than load operation, leading to a motor fever. Or frequent motor start, causing the motor overheating. This opportunity to burn motor will be blackened on both ends of the inner stator, the blackened parts was homogeneous (general motors has a fixed operating power, three phase generator call it the rated power and unit for tile, if under certain circumstances make up more than the actual use of power of the motor rated power, has described the phenomenon as motor overload). Insulation: motor internal insulation does not accord with a standard, existence and turn-to-turn short circuit. Or internal wiring error. This burning machine and sometimes confusing overload burning machine, stator can also be blackened, but in the short circuit parts will have obvious burn marks, such as copper lutetium will appear sometimes. The local severe burn winding. Lacks burning machine is: 1, the motor is star (Y) connection: there are two phase winding will burn, can use a megger (shaking table) to measure the two phase winding insulation damage. In short: if the motor is because of lack of phase and to burn, there will be a winding is not burned, if because of the heavy load and motor burn is full of three-phase motor winding insulation damage. 2, the motor is delta connection: will burn off only one phase winding, can use a megger (shaking table) to measure the phase winding 8500w gasoline generator insulation damage.

The asynchronous motor fault analysis

Due to the large motor current is too large and the change of supply voltage and single phase operation, mechanical, manufacturing bruised bad insulation damage caused by such as winding interturn short circuit, short circuit between windings, winding interelectrode interphase short circuit and winding short circuit. 1. The fault phenomenon Ion of the magnetic field distribution, unbalanced three phase current and make the motor vibration and noise when running, serious when motor can't start, and have great short-circuit current in coil of short circuit, lead to rapid heating coil and burned. 2. The reason Insulation insulation aging motor overload for a long time, lost; Wire insulation damage; Winding be affected with damp be affected with damp decreased insulation resistance caused by insulation breakdown; End and not cushion layer insulation material or plastic damage; End connection wire insulation damage; Or been struck by lightning overvoltage insulation breakdown; Friction between rotor and stator winding end insulation damage; Too many metal foreign bodies fall into the inside of the motor and oil pollution. Methods to examine 

3. (1) the external observation method. Observation of junction box, winding end with or without burning, winding overheating after leave a dark brown, and has a bad smell. (2) temperature control method. No-load running for 20 minutes (found abnormal should immediately stop), with the back ac synchronous motor of hand touch winding parts is more than normal temperature. (3) the electricity experiment method. With current meter measurement, if one phase current is too large, magnet generator have indicated that the phase short circuit. (4) the bridge inspection. Measuring a winding dc resistance, general difference should not exceed 5%, such as more than small, resistance of a phase short circuit fault. (5) short circuit detection method. There is a short circuit the winding under test, the sheet steel can produce vibration. (6) multimeter or megohmmeter. And any two phase winding insulation resistance measurement, if the reading of the minimum or zero, shows that the two phase winding and has a short circuit. (7) voltage drop. After the three winding in series into the low voltage security alternating current (ac), the measured reading a group of small fault. (8) current method. Motor no-load running, to measure the three phase current, in two phase switch, measure and contrast, if he does not change with the power switch, a phase winding large current has the short circuit. 4. Short circuit processing method (1) the short circuit point in the end. Insulating materials available to separate short-circuit point, also can be double insulated wire, to paint drying. (2) short circuit online slot. After the softening, find out the short circuit point repair, back into the trough, then paint drying. (3) the short route turns less than 1/12 of each phase winding, the serial number of turns all cut short route, connect the conduction part, forming a closed loop, supply urgent use. (4) winding short-circuit point when www.facebook.com/dongfeng.motor the number of turns more than 1/12, to dismantle all rewind.

Electrical engineer developed efficient motor technology

The key to reduce the loss of highly efficient motor all kinds of technology research, the main way is to reduce the motor loss, this requires the motor on the mechanism of all kinds of loss extremely thorough and meticulous research, to develop the potential of reduce the loss of all kinds of, this is no longer a single electromagnetic design, it is based on the traditional motor design model to establish a more power electric motors accurate mathematical physical model, and considering the process, material, machining accuracy, the structure, the ratio of various factors such as study, put forward to solve the key technology to reduce the loss of all kinds of motor and the design technology, including the structure design and manufacturing technology of super efficient motor, the rotor parameters, to reduce the power consumption of copper winding technology, reduce the power consumption of the wind the wind road components, ventilation system and the design of the bearing system, motor manufacturing technology research in order to reduce additional loss, etc. In conclusion, to develop highly efficient motor can be developed the key technology needed to do the job are briefly summarized as the following aspects: 1) in the motor loss calculation and analysis research: traditional calculation method based on the analysis of the magnetic circuit loss and play a major role in China's past series motors are designed, such as Y, Y2, Y3 series induction motor, but this method exists empirical coefficient is various, such as local distribution cannot be analyzed loss limitations. 

In order to solve this problem, the researchers conducted at home and abroad based on modern computer technology for the analysis of loss of the new study, this respect is the most widely used finite element method,www.facebook.com/dongfeng.motor this method can easily handle arbitrary structure and arbitrary boundary conditions and complex problems brought by the source distribution, at the same time can also plan and saturation within the motor and nonlinear complex problems, such as in motor design has a unique advantage. Against the super-efficient motor loss for this reason, the finite element simulation analysis and research, to reveal the motor internal loss characteristics from the microscopic view has important theoretical value, but also can be in order to further study how to improve the motor structure design to provide necessary technical reference. 2) on the motor loss factors and structure improvement research: because of the influence of the motor loss factor is various, involving motor iron core structure, winding structure and manufacturing process, and so on. Most the influence factors of the core structure, which mainly includes the stator slot,acmotortrading.blogspot.com and the air gap size, chute and groove Angle, the size of the trough, trough type (closed slot or semi-closed slots) and stator side structure, etc. For decades, limited to the limitation of calculating method, in the design of asynchronous motor, the influence of core structure use no more saturated theoretical value or experience value, the processing method can't for a specific factors on the specific impact of the loss of an in-depth study. Therefore, in the super efficient early motor development, the need for different motor structure finite element model is set up, by changing the parameters of different motor structure and material properties, analyzed the influence extent of different factors on the motor loss of concrete based on the optimal design scheme, and finally to achieve. 3) in the motor loss test research: in the latest IEC motor test standard IEC60034-2-1 the rotary motor (except for traction motor) to determine the efficiency and loss test method, the regulation IEEEl12B method as the only test method of low uncertainty. So, if you want to develop real conform to the high level of efficiency of motor, must be in low uncertainty of IEEE 1 I 2 b method system research, the focus is to study the precise measurement of the input power under the condition of low power factor, low uncertainty of additional loss and efficiency testing technology as well as the uncertainty evaluation techniques. 4) to reduce the loss of other measures, the development of highly efficient motor, also involves motor core materials, winding type and manufacturing process and how to reduce the mechanical consumption research, by conducting such studies can be from a certain 8500w gasoline generator extent, reach the purpose of consumption.

Stepper motor maintenance points Electrical engineers

Stepper motor as a digital actuators, widely used in the motion control system. Many users friends when using stepper motor, sensory motor work with larger fever, suspicious, I do not know this kind of phenomenon is normal. Fever is actually a common phenomenon of stepper motor, but how the degree of fever is normal, and how to minimize the stepper motor fever General electrical engineer pointed out that first of all, to understand why stepper motor fever For a variety of stepper motor, the internal is composed of iron core and the windings. Winding resistance, electricity will produce loss, the loss is proportional to the square of the size and the resistance and current, this is the copper loss, we often say that if the current is not a standard dc or sine wave, will also produce harmonic loss; Core has hysteresis eddy current effect, also can produce loss in the alternating magnetic field, its size and material, current, frequency, voltage, this is called iron losses. Copper loss and iron loss will be displayed in the form of heat, which affects the efficiency of the machine. Stepper motor general pursuit of position precision and torque output, the efficiency is low, the current is compared commonly big, high harmonic components, the frequency of the alternating current is also change with speed, thus stepping motor are widespread fever, than the general ac motor serious condition. Moreover, to control the step motor heating within a reasonable range Electric heating allows to what extent, depends on motor internal insulation class. Internal insulation performance at high temperatures (130 degrees) will be destroyed. So as long as within no more than 130 degrees, the motor will not damage, while the surface temperature under 90 degrees. So, step motor surface temperature in 70-70 degrees are normal. Simple useful point thermometers, temperature measurement method can also be rough judgment: by hand can touch more than 1 to motor part 2 seconds, no more than 60 degrees; Only with the hand touch, about 70-80 degrees; Drop a few drops of water gasification rapidly, more than 90 degrees; , of course, also can be used to detect temperature gun. Third, the stepper motor heat change with speed Using constant current drive technology, stepping motor under static and low speed, the current will remain relatively constant, to maintain a constant torque output. High speed to a certain extent, the motor internal counter potential, current will gradually decrease, the moment will decline. Therefore, because of the copper loss of fever is related to the speed of the story. Generally high fever when static and low speed, high speed low fever. But the iron losses (smaller) while the percentage of change is not at all, and motor of the fever is the sum of the two, electrical engineer pointed out that the above is just normally. Fourth, the effects of fever Motor heat while generally will not affect the life of the motor, for most customers don't need to ignore. However, serious fever can bring some asynchronous motor negative impacts. Internal parts such as motor thermal expansion coefficient of different lead to the change of structural stress and internal air gap of tiny change, affects the dynamic response of the motor, high speed will be easy to out of step. And as some situation does not allow excessive heating of the motor, such as medical equipment and high-precision test equipment, etc. So the control of the heating of the motor should be necessary. Finally, reduce the heating of the motor To reduce fever, is to reduce the copper loss and iron loss. Reduce copper loss, there are two directions, resistance and current, choose as far as possible when this request in the selection of small resistance and the rated current of the motor, the two-phase motor, motor without parallel in tandem. But this often conflict with the moment and the requirement of high speed. For motor has been selected, should make full use of the drive of automatic flow control function and offline function, the former automatically reduce current when motor is static, the latter will be the current be cut altogether. In addition, the subdivision driver due to the current waveform is close to sine, less harmonic, electric heating will be less. Reduce iron loss method, related voltage level, although will bring high speed characteristics of high pressure driven motor, but also brings the increase of the heat. So should choose the appropriate drive voltage grade, www.facebook.com/dongfeng.motor recommend suite, give attention to two or morethings stationarity and fever, noise, etc.

The reason of smoking ac motor overheating

Ac motor overheating smoking causes are: (1) cage rotor broken bar or wound rotor winding wiring loose, the broken and loose, repair welding or fastening screws; (2) the power supply voltage is too high, if the supply voltage exceeds bid is bigger, is solved by power supply departments; (3), rotor core motorcycle rub, if the bearing clearance overrun, replace the new bearing. If the axis of bending and straightening process. If the core looseness, www.facebook.com/dongfeng.motor deformation, processing core; (4) the surface of the winding with grime, foreign body, cleaning or washing motor; (5) the motor start or amounts of positive and reverse frequently, reduce the motor start and the number of positive and reverse, or change the suitable motor; (6) motor overload or drag mechanical resistance motor part is too large, eliminate drag mechanical failure, reduce the resistance. If more than rated current, it is necessary to reduce the load. Replace the large capacity motor or adopt measures to increase; (7) the power supply voltage is too low, if the power cord pressure drop is too big, change the coarser the power cord. If the supply voltage is too low, is solved by power supply departments; (8) winding asynchronous motor turn-to-turn, interphase short circuit, winding grounding, check out; (9) inlet air temperature is exorbitant, check the cooling unit and the surrounding environment temperature; (10) motor open phase running, check the fuse, switch contact point, troubleshooting; (11) caused poor ventilation fan fault, check the fan, whether the blade deformation, damage or loose, replace when necessary; (12) after rewind, winding dipping, "secondary" leaching paint processing, or use vacuum varnished measures; (13) winding wiring error, change; (14) higher environmental temperature, or motor ventilation congestion,

Three-phase asynchronous motor starting method

Squirrel-cage three-phase asynchronous motor in the widely used now. This kind of motor in the design process focuses on at work can not only realize good use of intelligent control, and in the process of use and not due to the use of a lot of power to grid used in daily life, work, a certain power impact. The squirrel-cage three-phase asynchronous motor in use process, by the use of gf in use process is usually via step-down start to start the motor, now use the step-down start there are two main ways, one is step-down motion, while another is called soft start. Soft start is also called electronic soft start, the startup mode generally adopts 16-bit single chip microcomputer to be responsible for rotor and stator the control of the motor, through the intelligent control system, the motor at work can ensure that the motor in the load it can achieve a smooth start, still can reduce because click use too much power and cause certain impact to the grid. Including the squirrel-cage three-phase asynchronous motor in before and now, the grid has always maintained a in the process of running with the characteristics of volatility, often at the time of peak electricity consumption, electricity in use process found obvious battery is low, but in the case of electricity consumption is very low, there will be a power's use of power is very high. In order to some of the production process can fully more rational use of electricity, people invented the electric motor electronic soft starter, this product motor fan with this product, the squirrel-cage motor is applied. The squirrel-cage motor such as the electromagnetic brake is also need in step-down startup conditions. In the process of this kind of motor start, machine can't work under full pressure start mode, and when it starts, terminal voltage can't realize the characteristics of the specification requirements.

Electric motor, Electric motor), also known as the motor or motor

Electric motor, Electric motor), also known as motor or motor, is a kind of electrical energy into mechanical energy, mechanical energy and can be used to produce kinetic energy, electrical equipment used to drive other devices. The various types of motor, but can be roughly divided into ac motor and dc motor to be used for different occasions To compare DC Motor (DC Motor) in the speed for the benefits of relatively simple, only control the size of the voltage has control of speed, but this kind of Motor is unfavorable in operating conditions such as high temperature, flammable, and due to the need to carbon brush Motor (am) as current converter components (brush Motor), so need to regular cleaning brush friction generated by dirt. lamination motor No carbon brush motor is called the brushless motor, relative to the brush, brushless motor because of less carbon brush and shaft friction so more save electricity and quieter. Production difficulty is higher, the price also is higher. AC Motor (AC Motor), on the other hand, works under high temperature, flammable, and need not regular cleaning of carbon brush dirt, but in the speed is more difficult, because the control of AC Motor speed to control the frequency of the alternating current (or the use of induction motors, with increased internal resistance decreased under the same the frequency of the alternating current Motor speed), the control of the voltage will only affect the torque of the Motor. General civil motor voltage of 110 v and 220 v two kinds, such as in industrial applications and 380 v or 440 v type. The development history In 1835, produced the world's first motor can drive the application of small trolley for us a Smith of Wen Bo (Thomas Davenport). In the early 1870 s, the world's earliest available commercial motor by the Belgian electrical engineer Zenobe Theophile Gamme invention. In 1888, a famous motor part American inventor nikola tesla used Faraday electromagnetic induction principle, invention of ac motor, is the induction motor.

 In 1845, the British physicist huis (Wheatstone) to apply for the patent of the linear motor, but the principle in the 1960 s were seriously, and design the practicability of the linear motor, the current has been widely applied in industry. In 1902, the Swedish engineer Dan nelson use tesla induction motor rotating magnetic field of the concept, invented the synchronous motor. In 1923, the Scot James Weir French invented type three-phase Variable reluctance (Variable reluctance) stepper motor. In 1962, through the help of hall element, a practical DC brushless motor finally. In the 1980 s, the utility of ultrasound motor starts. The principle of The basis of the rotation of the motor principle for Buddha to Ming left hand rule, when a conductor is placed in a magnetic field, if the conductor is applying a current, wire will cut magnetic lines to make wires produce movement. Current into the coil magnetic field, using magnetic effect of current, make the electromagnet in fixed magnet rotating device in a row, can convert electrical energy into mechanical energy. With a permanent magnet or produced by another group of coil magnetic field interact to produce power Is the principle of dc motor stator, the rotor in accordance with the interaction force generated by the direction of the movement. Ac motor stator winding coil is on alternating current (ac), to produce a rotating magnetic field, rotor rotating magnetic field to attract together to make the basic construction of dc motor including rotary motion "armature", "field magnet", "the collector ring", "brush". Armature: can around the axis of rotation of the soft iron core coil. Field magnet: produce the magnetic field strength permanent magnet or electromagnet. Collector ring: coil two ends to about two semicircle collector ring, with the coil rotation, to change the direction of the current device. Each roll (180 degrees), half a circle on the coil current direction will change again. Brush, usually made from carbon brush contact collector ring fixed position, used to connect to the power supply. The basic structure Many different kinds of motor, with the basic structure, www.dongfeng-motor.com its composition is mainly composed of the Stator (Stator) and the Rotor (Rotor). Stationary in the space of the stator, the rotor can be circuition, is supported by bearings. To expect a certain air gap between the stator and rotor, to ensure that the rotor can free rotation. On the stator and rotor winding coil, a magnetic field on the current, become electromagnet, the stator and rotor one of them for a permanent magnet.

The principle of three phase asynchronous motor

Creates a to synchronous speed n1 along the circle space inside the stator and rotor rotate clockwise rotating magnetic field. Due to the rotating magnetic field in the n1 speed rotation, ac induction motor the rotor conductor is still at the beginning of the rotor conductor will cut the stator rotating magnetic field and produce inductive www.facebook.com/dongfeng.motor electromotive force (judge the direction of the induced electromotive force with the right-hand rule) due to the rotor conductors sub is short circuit loop at each end, and the effect of induction electromotive force, the rotor conductors will occur basic consistent with the direction of induction electromotive force induced current. Rotor current ac synchronous motor carrying conductor in the role of the stator magnetic field by electromagnetic force (force in the direction of the left hand rule determine) electromagnetic force on electromagnetic torque, rotor shaft drive rotor spinning in the direction of the rotating magnetic field. By analyzing the working principle of the motor can be summarized as follows: when the three-phase stator winding of the motor (the difference between a 120 - degree Angle) to the balanced three-phase alternating current (ac), will happen in a rotating magnetic field, the rotating magnetic field cutting rotor winding, which occur in the rotor winding induced current (rotor winding is closed-cycle) rotor of current-carrying conductor in the stator rotating magnetic field under the action of electromagnetic force will occur, as to form the electromagnetic torque on the motor shaft, motor rotation, and the motor rotation direction is the same as the rotating magnetic field direction.

Three-phase asynchronous motor speed control method

Three-phase asynchronous motor's very logarithmic p and s slip can be too much to change speed. From the perspective of the nature of speed regulation, different ways of governing is nothing but change synchronous ac motor synchronous speed or not turn two. Widely used in the production of machinery is not the change in speed control method of synchronous speed of wound rotor motor rotor series resistance speed governing, chopping speed regulation, cascade speed regulation and application of the electromagnetic slip clutch, hydraulic coupling, such as oil film clutch speed regulation. Changes of the synchronous speed logarithmic multi-speed motor, stator can change of the stator voltage, frequency, frequency control of motor speed has no commutator motor speed regulation and so on. From energy point of view, when there is high speed control method and low speed control method of two kinds: an induction refers to the effective speed control is constant, so there is no slip loss, such as multi-speed motor, frequency control of motor speed and slip loss can be recovered speed control methods (such as cascade speed regulation, etc.). Have slip loss speed regulation method belongs to the low speed, such as rotor series resistance speed control method, the energy loss in the rotor circuit; Electromagnetic clutch speed regulation method of energy loss in the clutch coil; Hydraulic coupler speed regulation and energy loss in the oil of hydraulic coupling. In general slip loss increases with expanding range of speed regulation, if the speed range is not big, energy loss is small. This control method is used to change the stator winding of red way to change the cage ac motor stator polar logarithmic to achieve speed, features below: With a hard mechanical properties, good stability; No slip loss, high efficiency; Wiring is simple, convenient control, low price; Have used differential is bigger, cannot obtain smooth speed regulation; Can be used with regulating speed control, electromagnetic slip clutch, smooth speed characteristics of high efficiency. 

This method is suitable for don't need a stepless speed regulation small electric motors of production machinery, such as metal cutting machine tools, elevators, lifting equipment, fan, water pump, etc. Cascade speed regulation refers to the motor rotor winding circuit in series with adjustable additional potential to change the slip of the motor, to Motor vehicle achieve the purpose of speed control. Most of the slip power is absorbed by series of additional potential to recycle produce additional device, the absorption of returning the slip power grid or conversion of energy use. According to the slip power utilization way, cascade speed regulation can be divided into Y series three-phase asynchronous motor cascade speed regulation, mechanical cascade speed regulation and thyristor cascade speed regulation form, adopts thyristor cascade speed regulation, its characteristic is: Slip loss in the process of speed regulation can be back to the grid or production machinery, high efficiency; Installed capacity is proportional to the speed range, the investment province, apply to speed range in production machinery from 70% to 90% of the rated speed; Speed regulating device failure can switch to run at full speed, avoid production; Thyristor cascade speed regulating power factor is low, the influence on harmonic. This method is suitable for the fan, water pump and the rolling mill, mine hoist, the extrusion machine use. Frequency control method Frequency control of motor speed is to change the frequency of the motor stator power, to change its synchronous speed control method. Variable frequency speed regulation system is the main equipment to provide frequency conversion power of inverter, the inverter can be divided into ac - dc - ac frequency converter and ac - ac frequency converter two kinds big, cross - straight - to pay inverter are mostly used in China at present. Its features: There is no additional loss of high efficiency and speed the process; Application range is wide, can be used in the cage type asynchronous motor; Large range of speed regulation, and the characteristics of hard and high precision; Technology is complex, high cost, maintenance difficulties. This method is suitable for the requirement of high precision, better speed control performance.

Star delta start

1 the principle Learn the electrician will not star triangle how line. 1. When the load on the motor has no strict requirements and to limit the start torque motor starting electric fan motor parts current and motor can use 380 v/Δ connection condition star triangle boot method; 2. The method is: in the motor when the motor first starts, connect into the star connection, when the motor start again after successful will convert into triangular connection (via double-throw switch switch); 3. Because of the motor starting current is proportional to the power supply voltage, the power grid provided by the starting current is only 1/3 of the full voltage start current, but also start torque only 1/3 of the full voltage start torque. 4. Star triangle start, step-down starting at the expense of his power in exchange for a lower cost of starting current. So it defies and with the size of the motor power to determine whether to need to use the star triangle start, also depends on what kind of load, the general load when need to start the runtime negative light load can be used star triangle start, usually a squirrel-cage motor starting current is 5 to 7 times that of the running current, and voltage requirements for power grid is usually plus or minus 10%, in order not to form the impact to power grid voltage is too large to adopt star triangle start, general requirements in squirrel-cage motor power by more than 10% of the rated power transformer will be will use the star triangle. 

5. In the process of actual use, found to be the star triangle step-down starting motor starting electricalmotor1.blogspot.com 11 kw are needed, such as fan, 11 kw electric current when it starts at about 7-9 times (100) A, according to the normal configuration of the thermal relay can't start, it's no use (the draft) thermal relay with big and does protect the motor, so suggest using step-down start. Two conditions 1, the capacity of 7.5 KW three-phase asynchronous motor. 2, motor in starting the instant power grid voltage fluctuation is less than 10%, for not often start the motor can be up to 15%; If there are special transformer S transformer or 5 p motor, motor asynchronous motor allows direct frequently. 3, meet the experience formula: Ist/IN < 0.75 + ST \ 4 pn ST - public transformer capacity, KVA; PN - motor rated power, KW; Ist / - IN the ratio of the motor starting current and the rated current. 4, star triangle step-down starting motor three-phase winding six external terminal: A - X, Y and C - B - Z (hereinafter with rated voltage 380 v motor as an example) A. start star: X - Y - Z, A, B, C three termination three-phase ac voltage 380 v, the voltage of each phase winding, 220, A 380 v directly start current is greatly reduced, to avoid the excessive starting current impact on grid form. At this time of the torque are relatively small, but the motor can reach a certain speed. B. angular run: star start the motor for a period of time (about) a few seconds after reaching a certain speed, electric switch connect six terminals into a triangle, and again from 380 v power supply when each phase winding voltage of 380 v, torque and rotational speed is greatly increased, the operation process of motor in the rated conditions.

The choice of motor rated power

1. The mechanical mode of load steady continuous work, should choose according to the mechanical

shaft power. When the rotational inertia of ac synchronous motor the mechanical or starting static resistance torque is large, cage type motor and synchronous motor should be calibrated according to the starting conditions. Synchronous motor to pull in torque should also check. 2. The continuous work of the mechanical load change, general or equivalent torque should be according to the equivalent current method choice, and calibrated according to allow overload torque. 3. With respect to the manner of intermittent work machines, the power rating shall be according to the equivalent load of typical cycle of conversion to standard load sustained rate of the power to choose, and calibrated according to allow the load torque. 4. Machinery of short-time working, should choose short-term fixed motor, can also according to allow the motor load torque choose intermittent quota. With respect to the manner of intermittent work machinery, when load sustained rate is more than asynchronous motor 60%, should choose continuous rating motor. 5. Medium temperature of the motor using site should comply with the regulations of motor technical conditions, temperature, insulation class, when using the location of altitude and medium temperature does not accord with regulation of working conditions, the power of the motor should be in accordance with the provisions of the technical conditions. 6. The motor rated power should be selected according to the mechanical type and its important degree, proper www.facebook.com/dongfeng.motor reserve coefficient (load factor).

Permanent magnetic synchronous permanent magnet synchronous motor motor application prospect

Visible, dc thoughts have excellent authorized functions, its mechanical characteristics and speed characteristics are parallel lines, this is the characteristics of all kinds of switch electric thoughts have not. In addition, in fact, permanent magnetic iron remover. Dc current idea and starting torque, high efficiency, speed control, good static characteristic features such as easily. Good duty characteristics make dc thought for a long time before the 70 s, in the situation of speed regulation, duty supplications, nearly became a unique selection. However, direct current (dc) thought the authority of the fluff, the field winding on the stator attacks the main magnetic field, the large dc power idea often also equipped with commutating ac electric motor parts pole, in order to improve of the reversing of the motor function. Dc motor armature winding and been planted on the rotor commutator, dc power supply through the brush and commutator will direct current to the armature winding translates into alternating current in the armature winding, namely mechanical current commutation. Tumultuous authority limit the dc thought to further reduce the volume and weight, is double brush and commutator of the sliding contact caused by mechanical wear and spark, the direct current idea obstacle, the more trustworthy authenticity is low, life is short, cherish the maintenance of large amount of doing things. Commutation spark both the commutator of electric corrosion caused by nuisance source, or a radio will be harmless influence on the surrounding electrical equipment. Motor capacity, rotational speed is higher, the greater the subject becomes more important. 

So, in fact, permanent magnetic chuck. Ordinary direct current thoughts of brush and commutator limits the thoughts to burning with high speed, large capacity, depression and goods. On the switch power grid, people still usually manipulated exchange asynchronous electrical idea to drag xing machinery. Simple exchange asynchronous electrical thought has no authority, trustworthy real and long service life, low capital, cherish the simple maintenance. Compared with direct current (dc) idea, however, its speed control function is poor, small starting torque, overload talent and low efficiency. Carnegie-give must be the onset of a rotating magnetic field from the grid reactive power, so the power status is low, especially when the light load, which adds lines and large power consumption. Permanent, since you know that a strong permanent magnet. Without beg speed control of the situation, such as fan, water pump, the common machine tool drive, asynchronous electric thought according to a leading fame, of course, this type of drag, visible in a large number of energy wastage. Domain before the electric drive, rarely color synchronous electric thoughts, learn to permanent magnetic iron remover. Its main cause motor fan is synchronous electrical thought cannot under grid voltage starting, movement of the rotor pole under the effect of rotating magnetic field, uniform torque is zero. They are also great frequency conversion power can solve the starting and speed control of synchronous motor was thought subject, but in the 70 s, variable frequency power supply of equipment are to think about. So, before the domain of electric drive, using synchronous motor was thought as the original thoughts is seldom seen. In high power within the boundaries, has no intention of occasional synchronous electric thoughts running example, but it is often used to improve power factor of power grid enterprises.

The operation of the three-phase asynchronous motor monitoring

Three-phase asynchronous motor running monitoring: 1, monitoring, motor overheating 2, monitoring the working current of the motor is more than the rated current 3, monitor power supply voltage with or without changes 4, monitor whether the three-phase power supply voltage and current balance Note: in the operation of the three-phase asynchronous motor 1, pay attention to the ventilation of the motor and the environment 2, pay attention to the motor vibration 3, pay attention to the noise of the rotor cutting machine motor with or without abnormal situation 4, pay attention to whether motor abnormal smells 5, pay attention to the working condition and fever motor bearing Daily monitoring master electrician motor five often: 1, often listen to. Motor issue during normal working uniform "buzzing" sound. Particularly heavy motor part when I heard the "buzzing" sound, or "utter the word" sound, motor open phase running. If heard a continuous "guru" or "giggle" sound, that there is something wrong with the motor bearings 2, often have a look. See the ammeter or a voltmeter indicates whether or not the normal; See if three phase current balance; See whether the power supply voltage of three-phase; See if motor on the basis of solid, etc. 3, often monitoring environment temperature. The output power of the motor temperature has a great relationship with the surrounding environment, the environment temperature is higher, the smaller the motor output power. When the environment temperature below 35 ℃, motor power output will be greater than the rated power output, the increase of amplitude of (35) % (t for the actual environment temperature), but not more than 8% - 10%; When the environment temperature above 35 ℃, the output power of the motor than rated output power reduction (t - 35) %. 4, often feel. Back with your fingers touch the motor shell, temperature rise is too high. As the hot hand, motor has overheating. 5, often smell. Whether with his nose close to the motor, smell the smell of insulating varnish or anxious burnt flavour. If have, could be the result of a coil www.facebook.com/dongfeng.motor of motor overheating and short circuit, etc.

Research and development in our country the first hydrogen fuel electric locomotive

China's first hydrogen fuel cell electric locomotive "blue sky" has run successfully in southwest jiaotong university railway private sidings. "Blue sky" by southwest jiaotong university after 4 years of independent research and development, realize the fuel cell power environment, the permanent magnet synchronous motor and so on many technological breakthroughs, car, service unit, and the future can be widely used in engineering work station shunting, and other areas of the rail transit. Hydrogen fuel cell power is clean, efficient, safe and energy conversion rate is high, higher than the power characteristics, known as the century's most promising "green energy". As the ac synchronous motor industrial www.dongfeng-motor.com application of new energy, high stability and "zero emissions" and other characteristics of hydrogen fuel electric locomotive, is currently in Europe and the United States attaches great importance to and vigorously develop. "Blue sky" with 150 kw fuel cell as a traction, 2 units of asynchronous motor 120 mw permanent magnet synchronous motor as a traction motor, the design speed of 65 km per hour, continuous traction for 20000 cows, traction weight 200 tons, light load continuous operation 24 hours a day filled with hydrogen. Next, southwest jiaotong university "national rail transportation electrification and automation engineering center" will rely on, to continue to study on the basis of the hydrogen fuel power and battery power of the hybrid electric locomotive, realization of industrialization as soon as possible.

Submersible pump motor repair 10 points for attention

Mine submersible pump motor electromagnetic part and ordinary motor basic same, therefore, electromagnetic failure and repair, but due to the particularity of explosion-proof motor. In carries on the repair or reconstruction, it shall comply with the following provisions: The relevant personnel should understand, repair units and the relevant national laws and regulations, explosion-proof standards for repair work and the relevant provisions of the qualified products. Second, the unit should have for explosion-proof motor repair process equipment and the necessary inspection and test apparatus. Before three, maintenance, should prepare the necessary technical data. Four, commissioning before the motor repair, check the cable entry, relay protection and wiring system, to ensure that the company is still in good condition and conform to the requirement of explosion protection. Five, to engage in explosion-proof motor maintenance personnel should undertake the necessary training. After six, after inspection and acceptance of the inspection items, is made by authorization of the explosion-proof test unit or recognition, can be in repair units; Think it is necessary to project still explosion-proof test unit by explosion-proof inspection unit.

After repair, explosion-proof motor should be to use the department to provide the following documents: 1) fault inspection; 2) repair work instructions; 3) Motor vehicle replacement and repair parts catalog; 4) inspection and test results; 5) repair certificate. Eight, are not allowed to repair the piano pieces 1) by the size of glass, plastic or other unstable parts made of materials; 2) fasteners; 3) the manufacturer or explosion-proof code that can't repair parts, such as encapsulation component. A sign of nine, after the repair will not affect the explosion-proof performance of repair, after repair without repair. Ten, the flame-proof certification after after repair motor repair the repair unit inspection department shall issue certificate of approval. Described above shall include at least by repairing the name, type, specification, water pump explosion-proof motor logo, the name of the class units and its approval certificate number, explosion-proof certificate number, date of repair, etc. The standard code for GB3836.13-1997 after the repair. Signs must be norm, durable, and resistant to chemical corrosion. Signs should be metal materials, commonly permanently fixed on the motor after the repair, repair again, after repair, the previous repair sign shall be removed.

Electrical engineer driver amplifier

In electrical engineer concluded driver amplifier including logical explanation module and current amplification module. Driving amplifier accept stepper pulse, the direction signal input, such as output in the two groups (or groups) controlled current to two (or more) of the motor winding. Logical explanation module according to user's PC from stepping pulse and direction signals and offline, make each coil winding current switch in turn, so that the stepper motor rotor spinning. The motor works only two kinds of control engineering net all rights reserved, namely the whole work step and half step, step Angle is determined by the motor structure. When the basic step Angle can't meet the requirements, need to be subdivided driving. Where each input pulse switch, without current rotor cutting machine all-pass or broken, but only change the corresponding part of the winding current, thus the rotor are only part of the basic step is apart from the Angle of rotation. Segmentation function by precise control of motor phase current generated by the driver, has nothing to do with the motor. After segmentation, relatively stable output current change, to some extent, improve the output torque, reduce the low frequency oscillation of motor, improving precision permanent magnet motors for sale of step distance. Specific depending on the degree of segmentation and improve the quality of the driving circuit.

For good quality motor, generally more than 16 ~ 32 subdivision has no significant effect, but may slightly reduce the www.dongfeng-motor.com vibration and noise. Current amplification module logic signal amplification into working current. More commonly used is made up of field effect tube H bridge circuit. Field effect tube can be an electronic switch control engineering net all rights reserved, like the light switch. The use of this type on-off switch to adjust the current commonly used way is chopping constant current. Constant current is constant current. Chopper is cut need higher current wave. To a leaking water in the cup, for example, such as the speed is greater than the water leakage of water, sugar, and so as to avoid overflow. The field effect tube opening, the current rise. When the current just over, field effect tube shut off, the electricity was cut, fall off. Dropped to below setting, open field effect tube again, current rise again. Repeatedly switch with motor coil inductance, current stays at the set value. Need to point out that some of the driver amplifier calorific value (temperature) is not very big, some are small. The main reason is that most of the field effect tube hundreds of milliohm resistance are. Most optimal company Shanghai drive field effect tube resistance between 10-30 milliohm, so much smaller calorific value than ordinary drives. The surface temperature of the drive is associated with heat and heat dissipation area. Shanghai optimal abro drives due to the small size (matchbox size), so although the calorific value is very small (typically less than 1-2 w), but in some large current (4 to 8 a) the workplace, still need to install it on the offer of flange and fixed on the motor or the cabinet to heat dissipation.

Motor starting before the examination

New or stop using the motor for a long time, before the use should check between the winding and winding insulation resistance to ground. Usually below 500 v for the motor insulation resistance meter with 500 v; The 500-1000 with 1000 v v motor insulation resistance meter; diesel generators prices Of more than 1000 v motor insulation resistance meter with 2500 v. Insulation resistance shall not be less than 1 m Ω work every kv voltage, and measured motor part in the condition of motor cooling. (2) check whether there is any crack www.dongfeng-motor.com on motor appearance, all fastening screws and parts are complete, the thinking of fixed situation are in good condition. (3) check the motor drive mechanism work is reliable. As shown in (4) according to the nameplate data, such as voltage, power, frequency, coupling, rotating speed and power supply, if load is consistent. (5) monitor the ventilation of the motor and bearing lubrication situation is normal. (6) turn the motor shaft, check that the rotor can free rotation, the rotation has no noise. (7) to check the motor brush and brush lifting mechanism is flexible assembly, for the location of the brush handle is correct. (8) check reliable electrical grounding device.

Hot summer, the motor running problems should be paid attention to

In the operation of the motor in the hot summer work should pay attention to the following: 1, monitoring the power supply voltage change in voltage should not be more than or less than 10% of the rated voltage range, if lower than this range, should be appropriately reduced load operation. At the same time, the three-phase voltage imbalance also cannot too much. The difference of any two phase voltage should not exceed 5%, otherwise will make motor fever too fast. Motor power are best a voltmeter and switch directly to monitor. 2, monitors the running motor current Under normal circumstances operation shall not exceed the nameplate rating. Also should pay attention to whether the three phase current balance and any two interphase current difference should not be more than 10% of the rated current, otherwise the motor has a fault. Particular attention to whether there is a lack of phase operation. Shall furnish ammeter monitoring of large capacity motor running current, capacity should also be smaller motor line current is measured with a clip-on ammeter at any time. 3, monitoring the temperature of the motor The temperature rise shall not exceed allow the limits of the motor nameplate. In operation of the motor temperature rise is monitoring the motor running condition of direct and reliable way. Check the temperature rise method can refer to the 144 q. Online road furnish voltmeter, ammeter, and overload protection device, also is Motor vehicle the main way to monitor the temperature rise. 4, monitor the motor running in induction motor price the noise, vibration and smell when the motor running, voice even, smooth operation, insulating paint smell and the smell. In case of abnormal noise, vibration, insulating paint smell, etc., that motor overheating or other failures. 5, surveillance gear work To watch if there's any loose for pulley or coupling, transmission belt with and without sliding phenomenon (sliding belt is too loose), belt joint are in good condition. 6, monitor the condition of the bearing Pay attention to the bearing noise and fever. When using a thermometer to measure, rolling bearing heating temperature not over 95 ℃, sliding bearing heating temperature not over 80 ℃. Bearing abnormal sound or overheating, is poor lubrication bearing, wear and tear caused by severe. 7, monitor the condition of the fuse Should always pay attention to whether there is a photograph of blown fuse, lest cause lack of phase operation make the motor overheating. In a word, the motor in the process of running, monitoring the current, the change of temperature, found problems in a timely manner.

Vigorously promote application of high efficiency and energy saving motor electrical engineer

In order to improve the energy efficiency, energy conservation and emissions reduction goals, general electrical engineer is an important way promoting application in high efficiency and energy saving motor, this method is especially applicable to the need to run a long time and high load situations, such as steel, oil field, textile, chemical industry, etc., these motor used in the industry are often need to run 24 hours a day uninterrupted, if use the high efficiency and energy saving motor, energy-saving effect is very significant. This not only can save power to reduce production cost, has the good economic efficiency, at the same time also can reduce www.facebook.com/dongfeng.motor carbon emissions, produce good social benefits. Therefore, in terms of energy conservation and environmental protection, high efficiency, the development of highly efficient motor work is an urgent task. In the course of the development of efficient and highly efficient motor, an important task is to take to be able to gauge the wastage of the nonlinear and complex structure and various influencing factors of calculation method, the different structural parameters of stator rotor, material properties, and other motor part factors affecting the specific impact of motor loss, and various losses in the motor on the basis of system analysis, to improve the structure of the motor design, finally it is concluded that the best design plan, achieve the goal of consumption. , therefore, a detailed analysis on characteristics of the motor loss is the first task of super-efficient asynchronous motor research work, in order to achieve this goal, based on modern computer technology is a new loss calculation method for motor loss system analysis, from the microscopic view on how to develop the energy saving scheme has theoretical guidance meaning. In addition, in the process of asynchronous motor the development of highly efficient motor, accurate testing of the motor loss is also very important. For a long time, the motor structure and influence factors of additional loss is relatively complex, test is relatively difficult, previous treatment is using 0.5% of the input power to replace, and the proportion in the actual test does not reflect its true value loss, this will lead to some is not actually achieve efficient motor was judged to be efficient, make the motor efficiency defined error is produced. In IEC latest standards, clear recommendations according to the 112 b method to measure the additional loss, and the whole test process, accurate test and separation of the motor racing iron loss is a key link, but because of the influence factors of no-load iron loss is various, therefore, how to realize the accurate asynchronous motor racing iron loss test, test of super efficient motor loss and efficiency determine is of great significance.

The understanding of the three-phase asynchronous motor

Resection of the three-phase asynchronous motor power rely on inertia and rotation for a period of time (or distance) to stop, and a hook or hoist crane in the production of hanging basket require accurate positioning; Universal milling machine spindle requirements can quickly stop; Elevator after a sudden blackout need security protection and accurate positioning control... And so on. All of perkins diesel generator these need to drag brake motor, the so-called braking, is to give a torque and rotation in the opposite direction of the motor to make it quickly halt or limits its speed. Braking method generally has two kinds: mechanical braking and electrical braking. (a) mechanical brake Use machinery to make motor www.facebook.com/dongfeng.motor stalling method is called immediately after the power off mechanical brake. The commonly used methods: electromagnetic brake braking. 

1, the structure of the electromagnetic brake: Is mainly composed of two parts: brake electromagnet brake and brake shoe. Brake electromagnet by core, coil and armature of three parts. Brake shoe brake including brake drum, brake shoe, and spring etc, brake wheel and motor installed on the same axis. 

2, how it works: motor power, and electromagnetic brake coil electricity, armature and, to overcome the tension of the spring brake shoe and brake wheel, motor function. Disconnect switch or contactor, motor power, electromagnetic brake coil also lost electricity at the same time, the armature to separate from the core, under the action of a spring tension and make brake shoe hug brake wheel, motor is braking and halt. 

3, the characteristics of the electromagnetic brake braking Mechanical brake mainly adopts the electromagnetic brake, electromagnetic clutch brake, both magnetic field generated by electromagnetic coil after electrify make the static iron core produces enough suction and armature or moving iron core (electromagnetic clutch of moving iron core is sucked, dynamic and static friction piece separately), to overcome the tension of the spring and meet the requirements of the job site. Electromagnetic brake is to rely on the  electric fan motor parts brake shoe friction disc brake wheel. Electromagnetic clutch is the use of dynamic and static friction piece immediately when the power is enough friction between motor brake. Advantages: electromagnetic brake braking, braking force is strong, widely used in lifting equipment. It is safe and reliable, won't because suddenly loses power and accident. Weakness: the electromagnetic brake volume is larger, brake wear serious, rapid brake vibration can be created. 

4, motor brake clearance adjustment method 1) downtime. (mechanical and electrical close confirmation, pressure and power locks, and hung "is maintenance", "it is forbidden to start them.) (2) remove fan cover; (3) remove the fan circlip, remove fan blade; (4) check the residual thickness of the brake lining (minimum thickness of brake lining). (5) to check if the protective plate: protective plate edge has touched the dowel pin marks, must replace the brake disc; 6. Adjust the air brake clearance: three (four) to tighten bolts to the air gap is zero, then reverse loosen bolts Angle is 120 °, with feeler check the brake clearance (check at least three points), should be uniform and conform to the specified value; Please reset is wrong. (note: the brake model is different, its reverse unscrew Angle, the brake clearance is different). All landowners manual operation, brake action sound is ringing, stop position accurate and effective. Today the scene 6 s standard cleaning.