What are Limit Switches?

What are Limit Switches?

In comparison to other proximity sensing devices, limit switches are contact sensors that operate mechanically. When an object or target makes contact with the switch's actuator, it reaches the "limit," causing the electrical contacts to change state.

Limit switches offer several inherent advantages in their design:

  1. Versatility: They work effectively in various industrial settings.
  2. Low Power Consumption: These devices consume minimal power.
  3. Accuracy and Repeatability: Limit switches exhibit high precision and consistency in their operation.
  4. Multiple Load Switching: They can switch multiple loads simultaneously.
  5. Easy Installation: Limit switches are straightforward to install.
  6. Durability: These switches are rugged and reliable, designed to withstand demanding conditions.
  7. Heavy-Duty Electrical Contacts: Most limit switches are equipped with durable electrical contacts.

However, limit switches also have some limitations and restrictions:

  1. Operating Speed: They operate at relatively low speeds due to their mechanical nature.
  2. Contact Sensing: Physical contact with the target is necessary for them to function.
  3. Wear and Replacement: Over time, mechanical wear or fatigue may require eventual replacement.

In this article, we will focus on two classes of limit switches:

  1. Standard Industrial Oiltight: These switches are commonly chosen for industrial applications, offering robust performance in environments with oil, grease, dirt, high-pressure washdown, shock, or vibration. They typically meet various NEMA and IEC enclosure ratings. Two configurations are available: Plug-in, where the components are separated, and Non-plug-in, where the switch body and receptacle are in one piece.

  2. Precision Switches: These switches find applications in both commercial and industrial settings due to their precise operation, compact size, and affordability. They come in two styles: Basic Precision Switch, which is a one-piece construction, and Enclosed Precision Switch, featuring a two-piece die-cast housing with a gasket cover for a secure seal and protection against contaminants.