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 choice of single-phase capacitor electric mechanical and electrical capacity

The choice of single-phase capacitor small electric fan motor electric mechanical and electrical capacity Most of single-phase motor capacitor,such
acmotor2.blogspot.com as washing machines,electric fans,submersible pump,small woodworking planer,etc.But due to capacitor spoiled or improper selection capacity,Motor running temperature,noise,power consumption increases,the speed is reduced,the phenomenon such as torque decreases,here the selection of electrical and mechanical capacity of the capacitor motor approach to electricity Work friends can do a introduction,for your reference. Calculation method 1:Single-phase capacitor electric mechanical and electrical capacity depends on the size of the deputy winding current.

Because of different sizes,single phase motor power to consider when choosing capacitance rev Dynamic torque,speed,temperature,noise and loss should be within the normal range.So first of all should from the nameplate detect single-phase motor power,calculate the primary winding of the electricity Flow,and then according to the primary winding current (0.5 0.7) times to perkins diesel generator set calculate the current value of each winding current,according to the formula C = IC * 10 divided by 2 PI fVo.The formula of the I I = P = V is obtained. 2:the selection of capacitor Single-phase capacitor motor should first choose oil-immersed capacitor,pressure value should be above 400 v.Second optional www.facebook.com/guohong.trading ac electrolytic capacitor,its small size,low prices,but life Life is a bit short.

Why can't a general motors used in plateau area?

Elevation of motor temperature rise,motor corona (high voltage motor) have an adverse effect and dc motor of the reversing.Attention should be paid to the following three aspects:(1) the high altitude,the greater the motor temperature rise,the smaller the output power.But when the low speed permanent magnet generator temperature increases with altitude and lower enough to compensate the influence of altitude on temperature rise When the rated power output of the machine single phase induction motor is the same;(2) should be taken when using high voltage motor in the plateau corona proof measures;(3) the altitude against dc motor commutator,pay attention to the material selection of carbon brush.Why not light load operation machine?Motor light carriage row,can cause:(1) motor power factor is low;(2) the motor efficiency is low.www.facebook.com/guohong.trading Waste can cause equipment,operation is not economic.(1) the load is too large;(2) lack of phase,(3) air duct jam;(4) low speed running time is too long;(5) large power harmonic.