Knife switches, also known as gate knives, are generally used for AC and DC low voltage (not more than 500V) circuits that do not need to be cut and closed frequently. Their operating current cannot exceed the rated value at the rated voltage. On machine tools, the knife switch is mainly used as a power switch, and it is generally not used to switch on or off the working current of the motor. There are five types of knife switches: single pole, double pole and three pole. The commonly used three pole knife switches allow long-term currents of 100 A, 200 A, 400 A, 600 A, and 1000 A. The product models produced are HD (single-throw) and HS (dual-throw) series.
It is suitable for a complete set of power distribution devices with AC 50Hz, rated voltage to 380V, AC voltage to 380V, DC to 440V, and rated current to 1500A, as an infrequent manual connection and disconnection of AC and DC circuits or as a disconnector. among them:
1. Single-throw and double-throw knife switches with central handle are mainly used in substations. They do not cut off the circuit with current and are used as isolation switches.
2. The side-operated handle knife switch is mainly used in the power box.
3. The central front lever operating mechanism knife switch is mainly used in the switch cabinet for front operation and rear maintenance, and the operation mechanism is installed directly in front.
4, side front operation mechanical knife switch is mainly used in the front two operation, front maintenance switch cabinet, the operating mechanism can be installed on both sides of the cabinet.
5. Knife switches equipped with an arc-extinguishing chamber can cut off the current load. Other series of knife switches are only used as isolation switches and cannot be used indiscriminately.