Common Types of Limit Switches

Posted by Kunal Sutar on August 28th, 2018

As its name suggests, a limit switch manages the operations of machines that are equipped with moving parts connected to a switching action mechanism. Limit switches are used in avastarrange of industrial machinery to control the motion of devices performing activity on a production line, but these limit switches are also found in non-industrial applications, such as garage door opener units and electric motor operation. A limit switch is responsible for turning off the motor in the case of garage door opener that lifts the door before the door crashes into the lifting mechanism. The switch also triggers off the motor as the door closes, stopping it from being pushed into the ground.

When a limit switch is installed in a system, it can usually start, stop, slow down, or speed up an operations, as well as activate a forward or reverse process. In order to perform the above actions, limit switches are designed in a variety of different shapes, sizes, and capacity ranges to meet the differences in machine systems and production processes. A limit switch is usually composed of a series of electrical contacts linked to an actuator that manages the mechanical device which is responsible for on and off functions. Limit switch instruments are used in a wide range of applications due to their straightforward design, reliability and relatively simple installation requirements.

Types of Limit Switches

The performance of limit switch depends on a number of factors. In addition to the functional parameters and mechanical specifications of a machine, these factors include the mounting method, size and force capacity of the switch, as well as the stroke rate involved in the operating process. In order to reduce the potential for instrument failure and ensure proper functioning, it is important for a limit switch’s electrical rating to match that of the system into which it is being installed. The common types of limit switches used in industrial applications are: 

Heavy-Duty Precision Oil-TightIt is also known as the Type C limit switch. It features a straightforward wiring arrangement and comparatively easy installation. This device is mostlyreliable due to its long mechanical and electrical lifespan.

Heavy-Duty Oil-Tight and Foundry: When the need for load exceed the range of capacity for a precision oil-tight switch, a regular heavy-duty oil-tight model, also known as Type T, may be needed. It can also handle operating sequences unavailable on the Type C and can withstand high trip and reset forces. 

Miniature Enclosed Reed: This limit switch, is also known as Type XA, it is smaller in size and less expensive device made up of die-cast zinc. Miniature Enclosed Reed contains a constant array featuring a hermetically sealed reed, which makes it suitable for applications that need a high level of contact reliability or call up for environmental worries.

Gravity Return: Gravity return limit switch is usually involved in production line and conveyor operations involving lightweight components. There are severaldifferent varieties of gravity return switches, including roller type, lever type, spring return, top push, and maintained contact designs.

• Snap SwitchesA snap switch is designed to quickly trigger the switch as soon as the mechanism attached to the switch has traveled a fixed distance, irrespective of the speed at which the moving part travels. Snap switches are normally used in applications that need only basic constant parameters and can work with or without an operator.


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Kunal Sutar

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Kunal Sutar
Joined: August 17th, 2018
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