Limit Switch Categories and Applications
A limit switch is an electro-mechanical device that consists of an actuator mechanically linked to a set of contacts. When an object comes into contact with the actuator, the device operates the contacts to make or break an electrical connection. Limit switches are used in a variety of applications and environments because of their ruggedness, simple visible operations, ease of installation and operational reliability.
Limit switches are used in an assortment of applications and environments due to their ruggedness, simplicity of installation and reliability of operation.
Limit switches are available in a variety of body, rotary arm styles, operation requirements, and environmental factors including moisture, contamination, temperature, shock and vibration. Other factors to consider when selecting a limit switch include operating force, reset force, over-travel, pre-travel, along with safety requirements. Limit switches are also available in four unique categories: Global, Medium-duty, Heavy-duty and Safety Locking an Unlocking Styles.
Global Limit Switch
The Global limit switch is designed to IEC standards for world-wide acceptance. These metal or plastic switches are available with a wide variety of actuators, electrical specifications, terminations, circuitry and sealing ratings.
Global limit switch uses include:
- Injection molding machinery, PLC interface, machine tool equipment, elevators, escalators and moving stairs, gaming machines, material handling, packaging and textile equipment, food and beverage, industrial doors, scissor and platform lifts, electronic assembly equipment.
Medium-duty Limit Switch
Medium-duty limit switches can be classified as application-proven enclosed switches (precision snap-acting switches sealed in rugged metal housing). These limit switches are available with a variety of actuators, electrical specifications, terminations, circuitry and sealing ratings.
Medium-duty limit switch uses include:
Presence/absence detection where physical contact with an object is permissible, as well as applications requiring accurate repeatability and long life such as those found in overhead cranes and hoists, packaging and earth moving equipment, stamping machines, conveyors, surface transportation and textile machinery, printing equipment and farm machinery. Sealed versions are for wash-down applications.
Housed in a rugged, die-cast body, the limit switch is epoxy coated for protection. This limit switch offers a wide choice of mounting and actuator options. Low temperature and fluorocarbon (high temperature) construction, as well as factory-sealed, pre-wired versions, are available.
Heavy-duty limit switch uses include:
- Presence/absence detection in harsh duty environments where physical contact with an object is permissible such as food and beverage machinery, shipboard and dockside applications, caustic waste handling, power generating plants, pulp and paper equipment, welding machinery, automotive machine tools and conveyors.
Safety Locking and Unlocking Styles
These limit switches are used to protect personnel and equipment by monitoring the position of movable components.
Safety Locking and Unlocking limit switch uses include:
-
Machine tool, wood working, robots, material handling, plastic injection, baling machines, and packaging.
-
Safety limit switches are available in:
-
Key-operated interlock
-
Hinged guard
-
Solenoid locking
-
Emergency stop cable-operated
-
Limit Switch Video Overview
