Medium and small capacity of asynchronous motor is generally what protection is there?

(1),short circuit protection:general fuse is short circuit protection device;(2),loss of pressure protection:magnetic starter solenoid coil in starting motor control circuit loss of pressure protection.Automatic air switch,auto voltage step-down compensator are generally equipped with a pressure loss tripping device,so that in the above two cases plays a role of overload protection of
motor.(3),overload protection,thermal relay is the motor overload protection device.16,in asynchronous motor operation maintenance work should be paid attention to what?

(1),around the motor motor should be kept clean;(2),with the instrument to check the change of the power supply voltage and the current situation,general motors allow voltage fluctuation for the rated voltage of plus or minus 5%,the difference between the three phase voltage shall not be greater than 5%,the phase single phase asynchronous motor current unbalance value should not exceed 10% And attention should be paid to determine whether the lack of phase operation;(3),regularly check the temperature of the motor,commonly used thermometer temperature,temperature rise shall not exceed the maximum allowed should be paid attention to;(4),listening to the 5kw permanent magnet generator bearings with or without abnormal noise,sealing is good,and regularly to replace lubricating oil,the oil change period,general sliding bearing is 1000 hours,500 hours of rolling bearings.(5),pay attention to the motor sound,smell,vibration and transmission device.During normal operation,the motor should be uniform sound,no www.facebook.com/dongfeng.motor noise and special sound.

The cause of the three-phase asynchronous motor can't start

1),2) didn't plug in,blown fuse 3),4) circuit,stator winding of the stator or rotor winding grounding

5),and stator winding short circuit 6),7) of the stator winding wiring error,overload acmotortrading.blogspot.com or mechanical transmission was crushed loose article 8),the rotor copper 9),no oil in the bearing,axis due to heat expansion,obstruction in the bearing rotating 10) wrong wiring,control equipment or damage to the 11),over-current relay size 12),old starting switch oil cup of gasoline generator spare parts oil,13),wound rotor type motor starting operation error 14),wound rotor type motor rotor resistance with 15),bearing damage Three-phase asynchronous motor can't start many factors,a detailed analysis should be done according to Motor vehicleac tual condition and symptoms,carefully check,can't get to start for many times,especially when the starter motor when abnormal noise or overheating,should immediately cut off the power supply,after find out the reason and rule out any 220v ac electric motors starting,in case of failure to expand.

With a brush brushless

Brushless dc motor is composed of stator main body of the motor and drive, is a

typical mechatronics product. The stator winding of the motor to make more balanced three-phase y

connection, With three phase asynchronous motor is electrical motor 24v very similar. On the rotor of the motor with the magnetization of the permanent magnet has, in order to detect the polarity of the motor rotor, inside the motor is equipped with position sensing Device.

Drive consists of power electronic devices and integrated circuit, its function is: accept the motor

start, stop, brake signal, to control the start and stop of the motor Check and brake; Accept the

position sensor signals and positive &negative, used to control the inverter bridge on and off of

each power tube produce continuous torque; Accept the speed instruction and feedback Signal, which is used to control and adjust the speed; To provide protection and display, and so on. Because of brushless dc motor based on self-control type operation, so don't like frequency control of motor

speed synchronous motor overload start under plus startup winding on the www.dongfeng-

motor.comrotor, also do not When the load mutation generate oscillation and step out.

Medium and small capacity of the permanent magnet brushless dc motor (BLDCM), now more than using high magnetic energy product of rare earth ndfeb material (Nd - Fe - B) Material. As a result, the volume of rare earth permanent magnet brushless motor than three-phase asynchronous motor with capacity reduces a frame number. Nearly thirty years in view of the asynchronous motor frequency control of motor speed Research, in the final analysis is looking for a way to control the asynchronous motor torque, rare earth permanent magnet brushless dc motor is bound to its wide speed range, small volume, high efficiency and steady state Speed and small error characteristics appeared

in the field of speed advantage. Because of brushless dc motor has the characteristics of a dc motor, is also the electrical motor 12v 1000w device of frequency variation, so also known

as straight Flow frequency conversion, the international general term for BLDC) motors running

efficiency of the brushless dc motor, torque at low speed, precision of speed is more good than any

of the control technology of inverter, so value Attention to the industry. The product has

production more than 55 kw, can design to 400 kw, can meet the requirements of industry energy saving

and high performance drive. 

1, fully replace the dc motor speed control, comprehensive alternative, comprehensive alternative to asynchronous motor frequency converter + frequency conversion motor + reducer speed; 2, can run for high power at low speed, can save the reducer direct drive big load; 3, have all the advantages of traditional dc motor, and cancelled the carbon brush and slip ring structure; 4, torque characteristic is excellent, medium and low speed torque performance is good, big start torque, small starting current; 5, stepless speed regulation, wide speed range, strong overload capacity; 6, small volume, light weight, large output; 7, soft and soft stop, good braking performance, saves the original mechanical braking or electromagnetic braking device; 8, high efficiency, no excitation loss and carbon brush motor itself loss, eliminate the multiple reduction consumption, comprehensive energy-saving rate can reach 20% ~ 60%, power saving a year only to recover Cost; 9, high reliability, good stability and strong adaptability, simple maintenance and maintenance; 10, turbulence shock resistance, low noise, little vibration, smooth operation, long service life; 11, no radio interference, does not produce sparks, especially suitable for explosive place, explosion-proof type; 12, according to the needs of optional trapezoidal wave motor and is XuanBo magnetic field magnetic field. 

21 points for attention (1) before disassembly, should surface dust with compressed air blowing off the motor, and scraped perkins diesel generator setclean surface dirt. 2 choose motor working place, the disintegration of the clean up the scene environment. (3) familiar with the motor structure characteristics and maintenance technical requirements. (4) ready to collapse the required tools and equipment (including special tools). 5] in order to further understand the defects of the motor running, conditional when can do an inspection test before disassembly. Therefore, the motor with load test, detailed inspection machine Parts, such as temperature, sound, vibration, and test the voltage, current, speed, etc., and then disconnect the load, do a no-load check test, measure and no-load current No-load loss, recorded. [6] to cut off the power supply, electrical wiring to remove, recorded. Once the appropriate voltage test motor insulation resistance by megger are. Maintenance in order to keep up with The Times when measured insulation resistance compared to judge the trend of change motor insulation and insulation State, different temperature should be measured insulation resistance value conversion to the same temperature, the average conversion to 75 ℃. Being tested to absorb than K. When the absorption ratio greater than 1.33, which indicates that the motor insulation or degree of be affected with damp be affected with damp be affected with damp be affected with damp or not serious. In order to compare with previous data, should will likewise Any temperature measured absorption than the conversion to the same temperature.