Definition of Transfer switches
The Transfer switches, also known as a combination switch, is different from the operation of a knife switch. It is a plane operation that rotates left and right. The transfer switches have the advantages of multiple contacts, multiple positions, small size, reliable performance, convenient operation, flexible installation, etc. It is mostly used for the introduction of the power supply in the electrical control circuit of the machine tool. It functions as an isolated power supply, and can also be used as a direct control of small-capacity asynchronous The motor does not start and stop the control switch frequently. The switch also has unipolar, bipolar and tripolar.
The Transfer switch is a switching device that can be used to switch two or more power or loads. The transfer switch is composed of multiple contacts. In the electrical equipment, it is mostly used to switch on and off the circuit infrequently, connect the power supply and load, measure the three-phase voltage and control the positive and negative rotation of the asynchronous motor with small capacity – Triangle starter and so on. These parts are fastened together by bolts.
The Structural principle of transfer switches
The contact system of the transfer switches is composed of a plurality of movable contacts embedded in the insulating housing and the movable contact in the movable support. The movable contact is a double-breakpoint butt-type contact bridge. On the shaft with the handle, the circuit is turned on or off as the shaft rotates to different positions. The positioning mechanism adopts a wheel card ratchet structure and is configured with different limit members to obtain switches in different positions. The switch is assembled from multi-layer insulation shells, which can be three-dimensionally arranged, reducing the installation area, and the structure is simple and compact, and the operation is safe and reliable.
The change-over switch can be composed of switches of different connections according to the requirements of the line to adapt to the requirements of different circuits. In the control and measurement system, the switch can be used to convert the circuit. For example, the switching of the power supply of the electrical equipment, the forward and reverse switching of the motor, the commutation of the voltage and current in the measurement circuit, and the like. The use of a changeover switch instead of a knife switch not only simplifies the control circuit or the measuring circuit, but also avoids operational errors and also reduces the number of components used.
The change-over switch is a development of the knife switch. The difference is that when the switch is operated, the upper and lower planes move, and the change-over switch is a left-right rotating plane action, and a multi-contact and multi-position switch can be made.
Main uses of transfer switches
The transfer switches can be used as circuit control switch, test equipment switch, motor control switch and master control switch, and switch for welding machine.
The transfer switch is generally used in AC 50HZ, voltage up to 380V and below, DC voltage 220V and below to convert electrical control circuit and electrical measuring instruments. For example, commonly used LW5/YH2/2 type switch is often used to convert the measurement of three-phase voltage.
The combination switch is suitable for AC 50HZ, voltage to 380V and below, DC voltage 220V and below, for manual infrequent connection or breaking circuit, switching to power or load, can carry larger current.
Types of switching switches
The transfer switch LW5-16 YH3/3 letters and numbers indicate:
LW – “universal” anti-pinyin universal switch;
5– design serial number;
16–conventional heating current;
H–the initial letter of the “change” of the conversion;
LW5-16 YH3/3 means a universal transfer switch for voltage indication to convert phase-to-phase voltage.