Limit Switch, STAR ELEVATOR LTD

Components of a limit switch

Limit switches consist of an actuator with operating head, the switch body mechanism, and a series of electrical terminals that are used to connect the switch to the electrical circuit that it is controlling. The operating head is the part of the limit switch that comes in contact with the target. The actuator contains is connected to the operating head, whose linear, perpendicular, or rotary motion is then translated by the actuator to close or open the switch. The switch body contains the switch contact mechanism whose state is controlled by the actuator. The electrical terminals are connected to the switch contacts and enable wires to be joined to the switch through terminal screws.

Industrial machinery that undergoes automatic operations usually requires control switches that activate according to the movements involved in a machine’s performance. For repeat usage, the accuracy of the electrical switches needs to be reliable and their response rate should be prompt. Due to the mechanical specifications and performance parameters of different machines, factors such as size, operational force, mounting method, and stroke rate are important characteristics in the installation and maintenance of limit switches. In addition, a limit switch’s electrical rating should be matched to the mechanical system loads that it will be controlling in order to avoid instrument failure.

Limit Switch Uses and Operation

In most cases, a limit switch begins operating when a moving machine or a moving component of a machine makes contact with an actuator or operating lever that activates the switch. The limit switch then regulates the electrical circuit that controls the machine and its moving parts. These switches can be used as pilot devices for magnetic starter control circuits, allowing them to start, stop, slow down, or accelerate the functions of an electric motor. Limit switches can be installed into machinery as control instruments for standard operations or as emergency devices to prevent machinery malfunction. Most switches are either maintained contact or momentary contact models.