Views: 13 Author: Site Editor Publish Time: 2022-11-08 Origin: zhihu
The transfer switch is a switch that can freely convert the power supply. This kind of switch is also relatively common in our daily life. Many people are using the transfer switch, but they do not know the principle of the transfer switch. If you want to use a transfer switch, it is best to have a general understanding of the switch. This article will introduce what is the structural principle of the transfer switch.
A switchgear that can be used for the conversion of two or more power sources or loads. The transfer switch is composed of multi-section contacts. In electrical equipment, it is mostly used to make and break circuits infrequently, connect power and loads, measure three-phase voltage, and control the forward and reverse rotation and star-delta of small-capacity asynchronous motors. start etc. These parts are bolted together as a whole.
The transfer switch is also divided into manual and automatic.
The contact system of the transfer switch is composed of several static contact bases embedded in the insulating shell and moving contacts in the movable bracket. The moving contact is a double-break-point docking contact bridge. On the rotating shaft with the handle, the circuit is connected or disconnected with the rotating shaft to different positions. The positioning mechanism adopts a roller card ratchet structure, and is equipped with different limit pieces to obtain switches of different gears. The transfer switch is assembled from multi-layer insulating shells, which can be arranged three-dimensionally, reducing the installation area, with simple and compact structure, and safe and reliable operation.
The transfer switch can be composed of switches with different connection methods according to the requirements of the line to meet the requirements of different circuits. In control and measurement systems, switching circuits can be performed using change-over switches. For example, the switching of the power supply of electrical equipment, the switching of the forward and reverse rotation of the motor, the commutation of the voltage and current in the measurement circuit, and so on.
Using a changeover switch instead of a knife switch can not only simplify the control loop or the measurement loop, avoid operational errors, but also reduce the number of components used.
The transfer switch is a development of the knife switch, the difference is that the knife switch operates on the upper and lower planes, while the transfer switch is the left and right rotating plane action, and can be made into a multi-contact, multi-position switch.
