Limit switches are useful devices for monitoring and controlling industrial machinery or equipment. A limit switch not only controls, but also acts, as a safety device.

Depending on the application, you can use different types of level switches, such as furnace limit switch, rotary limit switch, high limit switch, fan limit switch, door limit switch, safety limit switch and temperature limit switch. Industries that use limit switches are automotive, aerospace, oil and gas, petrochemical, defense, food processing, medical and automotive.

Some important parameters you must consider before you buy a limit switch are:

1. Control parameter for which you want to use the limit switch
2. Operating environment of the limit switch
3. Maximum AC and DC voltage rating of the limit switches
4. Expected life of the limit switch

Action Steps
The best contacts and resources to help you get it done

Buy a limit switch from reliable manufacturers

Once you understand your requirements, evaluate different limit switches available on the market.

I recommend: Honeywell Sensing and Control is a global manufacturer that offers a range of limit control switch under the brand name Micro Switch. Automation Systems Interconnect is another reputable manufacturer offering limit switches and limit switch accessories. Euchner manufactures limit switches in different shapes and sizes using materials, such as plastic and aluminum. A-T Controls, a supplier of actuation systems, offers rotary limit switches that are corrosion resistant and explosion resistant. SVF Flow Controls, a leading valve manufacturer, offers limit switches made of aluminum with non-metallic enclosures.

Buy limit switches from distributors or retailers

Compare different limit switches based on their features and prices at distributors or retailers' websites. You can ask for a discount if you are buying in bulk.

I recommend: W.W. Grainger, a leading machine and tools distributor, offers limit switches of various brands, such as Square D, Schneider Electric and Omron. MSC Industrial Direct is another distributor offering range of limit switches, such as door limit switch, safety limit switch and rotary limit switch. M&M Controls, a reputable control instruments distributor, provides products from many large manufacturers, such as Automation Components, Siemens, Hedland and Fireye.

Buy a customized or specialty limit switch

Buy customized limit switches if standard products available in the market do not meet your requirements.

I recommend: Inertia Switch, a reputable switch manufacturer, offers custom-made switches according to your requirements. Precision Mechanisms is another switch manufacturer that provides custom-made switches for aerospace and industrial applications.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  Install limit switches properly, as improper installation may result in sudden failure.
• •  According to your requirement, look for other features such as corrosion resistance and vibration resistance while buying a limit switch.