As an engineer and related technicians, how to choose a […]
As an engineer and related technicians, how to choose an electric motor?
1. The type of power supply for the motor, such as single phase, three phase, direct current, etc.
2, the working environment of the motor, whether the workplace has special characteristics, such as humidity, high temperature, chemical corrosion, dust, etc.
3, the working mode of the motor, continuous work or short-term work or other work methods
4, the motor installation, vertical installation or horizontal installation
5, the power and speed of the motor, power and speed should meet the load requirements
6. Other factors, such as whether shifting is required, whether there are special control requirements, the type of load, etc.
Firstly, according to the requirements of the production machinery for the electric drive, such as the frequency of starting and braking, the speed regulation requirements, etc. to select the current type of the motor, and then the size of the rated voltage of the motor should be selected in combination with the power supply, and then by the production machinery The required speed and the requirements of the transmission equipment are selected for its rated speed. Then, according to the installation position of the motor and the production machine and the surrounding environment, the structure and protection form of the motor are determined. Finally, the power required by the production machine determines the motor. Rated power (capacity). Based on the above considerations, finally select the motor that matches the requirements of the motor catalogue.
There are several types of protection for the motor: open type, protective type, closed type, explosion-proof type, submersible type, etc. Usually, the open type is selected because it is cheap, but it is only suitable for dry and clean environment, and it is suitable for humidity and weathering. The dusty, flammable, corrosive environment should be closed, and the protective type can be used when the dust is not harmful to the motor insulation and is easily blown into the compressed air. As for the submersible pump motor, it should be completely sealed. In order to ensure that it is not intruded by moisture when working in water, when the motor is in a fire or explosion hazard environment, it should be noted that it must be explosion-proof.
The electric drive control circuit includes: electric circuit, continuous running circuit, positive and negative circuit, multi-ground control circuit, step-down starting line, multi-speed asynchronous motor control line, position control line, and the like.