As the name implies, the limit switch limits the operation of a machine that is connected in line with the switching action. Limit switches can be used to start, stop, forward, reverse, recycle, slow down, or speed up various operations. This simple device has many advantages and disadvantages.
Advantages of limit switch
Some of the strengths of the limit switch are listed below:
- It can switch high currents up to 10A.
- It has high precision, accuracy, and repeatability.
- Limit switch is cheaper in comparison to proximity or photoelectric switch.
- It can withstand the toughest environmental conditions.
- It can be used in almost any industrial environment.
- It consumes little electrical energy.
- It can control multiple loads.
- It has a compact size.
- It is easy to install.
- A wide range of limit switches, with various actuator heads, exist in the market, thus being able to detect the motion of any kind of moving object.
- The switch housing may be made from aluminum or plastic material, but in all cases, it protects the internal mechanism with superior electrical insulation and mechanical strength.
- Immune to electromagnetic interference.
- Mechanical durability up to approx. 30 million of operations.
Disadvantages of limit switch
Some of the weaknesses of the limit switch are listed below:
- It must make physical contact with an object to actuate.
- The mechanical component can wear out.
- Generally restricted to equipment operating at relatively low speeds.
- Its contacts can bounce.
- The response is slow compared with non-contact sensors such as proximity sensors.
- Limit switches are purely mechanical constructions, where the only electrical parts they have are their electric contacts.
- It may not be preferred in any application where noncontact actuation is required.