The temperature rise will not exceed the motor calibration allowable value when the variable frequency motor is operated under the standard environment. There is a great difference between the technology of the variable frequency motor and the ordinary motor. So how to distinguish the variable frequency motor from the ordinary motor?

　　1. From the perspective of working frequency, variable frequency motor is inferior, while ordinary motor is good.

　　2. As the PWM width modulation wave output by the frequency converter simulates sinusoidal alternating current and contains a large number of harmonics, it is generally necessary to pass through the filter of the reactor before entering the ordinary motor, otherwise the ordinary electric power will be heated.

　　3. In order to adapt to the output of frequency converter, the PWM width modulation wave analog sinusoidal alternating current contains a lot of harmonics. Specially made variable frequency motor. The effect is actually understood as reactor plus ordinary motor.

　　4. That is to say, the variable frequency motor with the same power is larger than the common motor core section. The coil turns should be multi-wire and large. High insulation, special cooling fan motor.

　　5. In order to adapt to the need of weak magnetic speed regulation, bearing capacity and high-speed rotor dynamic balance are considered.

　　6. This variable frequency motor does not have better torque characteristics, but only overcomes the need that ordinary motor is not adapted to the simulation of sinusoidal alternating current by PWM width modulation wave.

　　7. If the variable frequency motor does not have the above characteristics and requirements, it is a false variable frequency motor.