Why can't motors be used in plateau areas? Altitude has adverse effects on motor temperature rise, motor corona (high voltage motor) and commutation of DC motor.

The following three aspects should be noted:

(1) The higher the altitude, the higher the temperature rise of the motor, the lower the output power. However, when the temperature decreases with the increase of altitude enough to compensate for the influence of altitude on the temperature rise, the rated output power of the motor can remain unchanged;

(2) Anti-corona measures should be taken when the high-voltage motor is used in the plateau;

(3) The altitude is not good for the commutation of the DC motor, so pay attention to the selection of carbon brush materials.

Why does the motor generate shaft current?

The current in the shaft---bearing seat---base circuit of the motor is called shaft current.

reason:

(1) The magnetic field is asymmetric;

(2) There are harmonics in the power supply current;

(3) Poor manufacturing and installation, uneven air gap due to rotor eccentricity;

(4) There is a gap between the two semicircles of the detachable stator core;

(5) The number of pieces of the stator core with fan-shaped stacking is not suitable.

Why is the motor not suitable for light load operation?

When the motor runs at light load, it will cause:

(1) The power factor of the motor is low;

(2) The motor efficiency is low. It will cause equipment waste and uneconomical operation.

Why can't the motor be enabled in a cold environment?

Motors in a low temperature environment for too long will:

(1) Motor insulation cracks;

(2) Bearing grease freezes;

(3) The solder powder of the wire joint is powdered. 

Therefore, the motor should be heated and stored in a cold environment, and the windings and bearings should be checked before running.

Why is the leakage circuit breaker easy to trip when using frequency conversion?

This is because the output waveform of the inverter contains high-order harmonics, and the motor and the cable between the inverter and the motor will generate leakage current, which is much larger than that when the motor is driven by power frequency, so this phenomenon occurs.