Three-phase asynchronous motor speed formula: n = 60f / p (1-s) From the formula, we can see that change in supply frequency f, the number of motor pole pairs p and slip s can be changed to achieve the purpose of speed. Judging from the nature of speed, the difference about speed control is nothing more than two ways.To change the way the exchange of synchronous motor synchronous speed or not to change the speed. First，the number of pole-changing speed of the method This speed control method

In order to ensure electrical work, in addition to normal use in accordance with procedures, normal operation of the process of monitoring and maintenance of attention, but also should carry out regular inspection, maintenance electrical work to do a good job. This can eliminate some problems in time to prevent the failure to ensure safe and reliable operation of motors. Regular maintenance intervals can be considered in accordance with the form of electrical use of environmental decisions.Regul

Motor power should be based on the requirement of eqipment and make the motor run at rated load. pay attention to the following two points: If the motor power is too small. It will result in long-term motor overload. The insulation damage due to fever. Even the motor were destroyed. If the motor power is too high. The output mechanical power can not be fully utilized, the power factor and efficiency are not high, not only detrimental to users and power grids. But also result in wasted energy.

When the load of the asynchronous motor is not heavy, we can achieve energy saving by reducing the outside power. If the asynchronous motor runs normally and do not take no-load torque into thinking, the electromagnetic torque must be equal to the load torque. After the power is reduced, the main flux will decrease. At this moment the motor’s torque will decrease and the motor’s rotate speed will be reduced. Although this can increase the rotor current, however, when the load of the motor is l

A known three-phase motor capacity, and its rated current Formula (c): kilovolt capacity divided by the number of points to take factor 76.Description:(1) formula applies to any of the three-phase voltage calculation of motor rated current.By the formula and that formula may be the same voltage capacity , rated current of different motor is not the same,that is not the same as a few kV voltage,removal of the same capacity,from quotient is clearly not the same as, Quotient is not the same by the

The correct installation, use and maintenance of the motor, can avoid accident and extend the using life.一 Inspection 1,Check the nameplate data Carefully, and confirm the motor is correspond with the requirements. 2, Using the 500V megohm to measuring the motor insulation resistance between winding and shell, insulation resistance should be larger than 0.5MΩ二 Installation 1，Motor usually works in the clean and dry place, the surrounding should be well-ventilated, and the highest ambient air

1 A symbol of protection levels is by the characterization of the letters IP and additional representation in the latter two numbersWhich the IP is the English international protection (International Protection) of the acronym.The first digitalSpecific meaningBrief0No special protectionNo protective motor1To prevent accidental or accidental human touch on or near the shell of charged or rotating parts, diameter greater than 50mm to prevent the entry of foreign matter into the solid motorSolid pr

When the load of the asynchronous motor is not heavy, we can achieve energy saving by reducing the outside power. If the asynchronous motor runs normally and do not take no-load torque into thinking, the electromagnetic torque must be equal to the load torque. After the power is reduced, the main flux will decrease. At this moment the motor’s torque will decrease and the motor’s rotate speed will be reduced. Although this can increase the rotor current, however, when the load of the motor is l

Ordinary three-phase induction motors are all designed with Constant Voltage Constant Frequency,so it is impossible for them to adapt to the frequency conversion completely.The influences that the frequency converter produces to ordinary three-phase induction motors are showed as follows: 1.the efficiency and the temperature rising of motors Frequency converters of all kinds generate sinusoidal voltage and current of different levels during the operation,which makes motors running at non-sinusoi

With the shortage of resources, all countries are looking for the way to save energy and develop the potential of electric energy-saving. The only way is reduce the consumption.There are many ways for motor energy saving, such as improving motor efficiency, improving power factor, adjusting speed energy saving, Frequency Controlling speed. Now we discuss lowering energy consumption on the motor power factor. Asynchronous motor power factor changes with the load. Rated load power factor is highe