Packet-Type Switch

a manually operated electrical device for switching current on and off and rerouting current in low-voltage electric circuits of up to 500 volts and several hundred amperes. A packet-type switch consists of a group of contacts, a mechanism that moves the contacts and secures them in a particular switching position, and a housing. The contact system of packet-type switches of the knife-switch type consists of separate sections, each of which has an insulating plate with fixed contacts in the form of blades and also movable spring contacts that are insulated from one another. The major disadvantage of this design is the low wear resistance (not over 10⁴ switching operations). In a more advanced packet-type switch the contacts are closed and opened by a cam mechanism. The wear resistance of such packet-type switches reaches 2 X 10⁵ operations.

Packet-type switches are used on low-voltage DC and AC switching equipment, such as panels and consoles, in switching equipment for control and signaling circuits, and for direct cutting of low-power asynchronous motors into mains. They are also used in nonindustrial electric circuits and in household electrical appliances, including washing machines, fans, and vacuum cleaners.