Classification of ac motor

1,according to the working power supply classification:depending on the motor working power supply,can be divided into direct current motor and ac motor.Which ac motor is also divided into single-phase motor and three-phase motor. single phase generator 2,according to the structure and working principle of classification:motor according to the structure and working principle can be divided into small electric motors asynchronous motor and synchronous motor.Synchronous motor can also be divided into permanent magnet synchronous motor,synchronous motor and magnetic resistance motor with hysteresis.Asynchronous motor can be divided into ac induction motor and motor commutator.Induction motor is divided into three phase asynchronous motor,single-phase asynchronous motor and cover pole asynchronous motor.Communication is divided into single-phase series motor commutator motor,ac/dc motors and repulsion motor. 3,according to the classification of start-up and operation mode:the motor according to the start-up and operation mode can be divided www.dongfeng-motor.com into capacitor start motor,capacitor contributed to motor,capacitor start motor running and split-phase motors. 

4,according to the rotor structure classification:according to the structure of the rotor can be divided into the cage induction motor (old standard called squirrel-cage asynchronous motor) and wound rotor induction motor (wound asynchronous motor is called old standard). 5,according to the speed of classification:can be divided into the high speed motor,motor at low speed,constant speed motor and speed regulating motor.Has general is series of brush type ac motor,commonly used in small electric tools,such as some electric hair dryer,hand electric drill,the vacuum cleaner...Work with electric spark,noise is very big,but small size,large torque.Startup capacitor is used to produce to split phase of electrical motor single-phase ac power supply,using capacitor capacitive reactance of alternating current (ac),and after a coil in series,the overall current phase shift than simple inductor current phase shift,which USES two different phase current,the magnetic field to produce a different time,such as three-phase alternating current (ac),form a rotating magnetic field.

The total current measurement method

It is through the detection of IC power into the line of the total current,a method to judge strengths and weaknesses of IC.Because internal IC for the vast majority of direct coupling,IC damage asynchronous motor (such as a breakdown ac electric motor or open a p-n junction) will cause level after saturated with globe,bringing the total current change.So by measuring the electricalmotor1.blogspot.com total current method can judge of IC.Also available measure the voltage drop,power supply channel resistance,using ohm's law diesel generators prices to calculate the total current value.

What are the regulations on motor operation and matters needing attention?

(1) motor under the condition of rated cooling,according to the rated data stipulated in the factory

brand of the running,do not allow the limitation of ambiguous motor run blindly.(2) the motor coil

and iron core of maximum monitoring temperature should be according to the provisions of the

factory,such as the factory did not make clear a regulation should be according to the provisions of

the table below,the motor runs in any circumstance should not exceed the temperature rise.Insulation

class A grade B E F,resistance thermometer resistance thermometer resistance thermometer measurement method,static son 220v electric motor winding temperature rise of the temperature rise of 506060757080,8595100110105115,static iron core temperature,607580,95100115,the above-

mentioned numerical temperature when the environment temperature of 35 ℃ (3) allows the temperature of the motor bearings,should abide by the provisions of the factory.No manufacturing rules,according to the following provisions: A,for the sliding bearing,shall not exceed 80 ℃.B,for rolling bearing,shall not exceed 100 ℃ (poor quality of oils and fats,do not exceed 85 ℃) (4) motor can be changed at rated voltage general-5% to + 10% within the scope of operation,its rating unchanged.(5) the motor run in rating,and voltage unbalance rate shall not be greater than 5%,the difference of three phase current shall not be greater than 10%.(6) the motor is running,in each bearing measured vibration shall not exceed the provisions of the table below: motor speed vibration value (double amplitude) mm,3000 rpm0.05,1500 rpm0.085,1000 rpm0.10,750 RPM and below 0.12. 

Motor in the process of running in addition to the strict rules,should also pay attention to the following questions: (1) the current of the motor under normal circumstances should not exceed allowable values,the difference between the three phase current shall not be greater than 10%.(2) sound and smell: motor start capacitor during normal operation of the sound should be IE2/IE3 electric motor uniform normal,no noise;No coke smell or smoke near the motor,if found to have different sounds,measures should be taken to processing coke smell or smoke.(3) the performance of the bearing,mainly is the lubrication situation,lubricating oil is normal,the temperature is high,whether there is sundry.(4) other situations,such as cooling www.dongfeng-motor.com water system is normal,wound rotor motor brush on the slip ring is normal operation.

The failure of the motor to check electrical engineer

Motor fault check the motor fault processing, all kinds of methods of information on a variety. Some from the principle analysis, some experiences. (see electrical engineer) through experience, from the perspective of combining theory with practice to make specific analysis as follows. One, the motor starting motor not turn also perkins diesel generator no sound. Because the motor power supply or two phase or three phase winding circuit. First check whether there is a power supply voltage. Such as three-phase are no voltage, the circuit fault; If the three-phase voltage balance, fault in the motor itself. At this time to measure the resistance of the three-phase winding motor, find out the fault phase winding. Motor does not turn, but there are "buzzing" sound. Measure the motor terminal, such as three-phase voltage balance and the rating can be convicted of serious overload. Check step is, first remove the load, if the speed of the motor with a normal voice, which can determine overload or load mechanical part is faulty. If still do not turn, usable hand turn the motor shaft, if very tight or turn to be not moved, the three phase current measurement, such as three phase current balance, but may be larger than the motor part rating of the mechanical part of the motor was stuck on the motor oil shortage, bearing rust or damage is serious, end cover or oil cover too oblique, rotor and bore a collision sweep (also called bore). If you turn the motor shaft by hand to feel struggled with a certain way or at the sound of "scrape" cyclical, the chamber can be judged to sweep. 

The reasons are: (1) the bearing clearance between the internal and external ring is too big, need to change the bearing; (2) the bearing chamber (bearing hole) is too big, wear and tear caused by inner hole diameter is too large for a long time. Emergency measures is electroplating a layer metal or jacketed, can also be used in bearing small mark for the indoor walls; (3) the shaft bending, end cover through wear and tear. Motor speed is slow, and accompanied by "buzzing" sound, the shaft vibration. Such as measured one phase current is zero, and the other two phase current is far higher than the rated current, that is two phase operation. The reason for this is a circuit or power supply that open circuit or a motor winding phase circuit. A small motor phase break when available megohmmeter and multimeter or school lamp inspection. Check the star and delta connection of motor, must open the joint of the three-phase winding, whether measured each phase circuit. Medium capacity more than mostly adopts the motor of the winding wire and around many branch in parallel, if broken several root or disconnect a parallel branch is more complex. Often adopt the method of www.dongfeng-motor.com three phase current balance and resistance method, generally three phase current difference (or resistance) value is greater than 5%, the current small resistance (or larger) phase for opening phase. Practice has proved that motor circuit fault occurs at the end, or joint lead winding etc.