Limit Switches - Product Selection Guide

This Product Selection Guide contains information to help select products in the Limit Switches category on DigiKey.com

Snap action limit switches are mechanical devices that make or break an electrical connection by closing or opening electrical contacts or solid-state circuitry when actuated by human or mechanical interaction most commonly at a travel limit position. Limit switches are selected by actuator types such as an adjustable plunger or rod, toggle, arm lever, roller, cone, leaf, rotary actuator, spring, whisker, or cable.

SelectionCharacteristics

Circuit: Describes device function in terms of a number of poles and throws, as is typical for mechanical switches. For more information please see: Switch Basics, Examples of Pole and Throw

Switch Function: Refers to the specific operation or behavior of a switch, indicating the primary purpose or mode of operation. For more information please see: Switch Basics, Examples of Pole and Throw

Current Rating (Amps): Typically this represents the maximum current to which a device will meet its given specifications. Exceeding this current may damage the device and/or other system components.

Voltage Rating - AC: Typically this represents the maximum AC voltage rating to which a device will meet its given specifications. Exceeding this voltage rating may damage the device and other system components.

Voltage Rating - DC: Typically this represents the maximum DC voltage rating to which a device will meet its given specifications. Exceeding this voltage rating may damage the device and other system components.

Actuator Type: The specific design or style of the mechanism used to change the switch position.

Mounting Type: Indicates how the device is attached.

Termination Style: Selection of termination style used to connect the device to a system, such as cable leads, PC pins, or wireless.

Ingress Protection: IP (Ingress Protection) Ratings (IP20, IP65, IP67, etc.) - Define how likely it is that water and dirt will get into the system. The first number is for dirt and solid contaminants and the second number is for water.

Features: These are different capabilities or properties of the device such as LEDs, corrosion proof, or explosion proof.

Operating Force: Refers to the amount of force required to actuate or trigger the switch.

Release Force: The amount to which the force on a switch actuator must be reduced to allow an actuated switch to return to its rest position.

Operating Position: The specific position at which the switch is intended to change its state.

Pretravel: The typical amount of actuator travel between the rest position and the actuation point of a switch.

Differential Travel: The actuator travel distance between the switch’s operation and release points; its mechanical hysteresis.

Overtravel: The amount of switch actuator movement between the operating point and mechanical travel limit.

Operating Temperature: Recommended operating temperature, typically given in a range or as a maximum. Exceeding these temperatures may affect performance or damage the device and other system components.

ProductExamples

MediaLinks

Videos
E-Bits: WS Series Sealed Snap Action Switch from E-Switch
Snap Action Switches: E-Switch LS Series
E-Bits – SS Series Sub Miniature Snap Action Switches
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E Switch Part 3 Mini Nav and Detector Switches

Product Training Modules
NGC Series Limit Switch - Honeywell
Detect Switches - Copal Electronics
Electromechanical Switch Technology - Honeywell
Snap Switches - Omron
Sub-Miniature Snap Switches - C&K
DS Door Interlock Switch - C&K

If you have any general questions on the specifications for selecting Limit Switches, please reply using the button below. If you have questions on specific Limit Switches please post those questions in the Electromechanical Switches category.

Selecting the right limit switch is essential to ensure proper functionality and safety in various industrial applications. Limit switches are electromechanical devices used to detect the presence or absence of an object and provide feedback to control systems. They are commonly used in automation, manufacturing, and process control systems to monitor and control the movement of machinery and equipment. In this guide, we will outline the key factors to consider when selecting a limit switch.

Environmental Conditions:

The first consideration when selecting a limit switch is the environmental conditions in which it will be used. Different environments can pose challenges such as extreme temperatures, humidity, dust, vibrations, or exposure to chemicals. Ensure that the limit switch is designed to withstand the specific environmental conditions of the application. Look for switches with appropriate environmental ratings, such as IP (Ingress Protection) ratings for dust and moisture resistance, or NEMA (National Electrical Manufacturers Association) ratings for environmental protection.

Operating Speed and Force:

Consider the operating speed and force required for your application. Some limit switches are designed for high-speed applications, while others are more suitable for slower or heavy-duty operations. Determine the speed at which the object or machinery will be moving and select a limit switch that can respond accurately and reliably within that speed range. Similarly, consider the force or pressure that the switch will encounter and ensure it can handle the required load.

Sealed Plunger Actuator Limit SwitchSealed Plunger Actuator Limit Switch

Actuator Type:

Limit switches come with different types of actuators, which are the mechanisms that make physical contact with the object being sensed. Common actuator types include plunger, roller lever, whisker, rod lever, and spring-loaded. The choice of actuator type depends on factors such as the shape, size, and movement of the object to be detected. Consider the physical characteristics of the object and select an actuator that will provide reliable and consistent contact.

Contact Configuration:

Limit switches offer different contact configurations, including normally open (NO), normally closed (NC), and changeover (CO) contacts. The contact configuration determines the state of the switch when it is not actuated and when it is actuated. Select the appropriate contact configuration based on the requirements of your application and the desired behavior of the control system.

Electrical Ratings:

Evaluate the electrical ratings of the limit switch to ensure compatibility with your electrical system. Consider factors such as voltage, current, and maximum switching capacity. Ensure that the switch can handle the electrical load and voltage levels required by your application. Pay attention to the maximum switching capacity to prevent damage or premature failure of the switch when handling high currents or voltages.

Mounting and Connection Options:

Consider the mounting and connection options available for the limit switch. Common mounting types include panel mount, surface mount, and DIN rail mount. Choose a mounting option that suits the specific installation requirements and the available space. Additionally, consider the connection options, such as screw terminals or quick-connect terminals, and select the one that is most convenient for your wiring setup.

Safety and Certification:

If your application involves safety-critical functions or compliance with specific industry standards, ensure that the limit switch meets the necessary safety and certification requirements. Look for switches that are certified by recognized organizations or comply with industry standards such as UL (Underwriters Laboratories), CE (Conformité Européene), or IEC (International Electrotechnical Commission).

Reliability and Durability:

Reliability and durability are crucial factors when selecting a limit switch. Look for switches from reputable manufacturers known for producing high-quality and reliable products. Consider the expected operational lifespan of the switch and any maintenance requirements. Additionally, check for features such as built-in surge protection, self-cleaning contacts, or sealing options to ensure long-term reliability and minimize downtime.

Application-specific Features:

Depending on your specific application requirements, consider any additional features or functionalities that may be beneficial. For example, some limit switches offer LED indicators for visual status indication, adjustable sensitivity for fine-tuning, or wiring options for ease of installation. Assess your application needs and identify any additional features that can enhance the performance and functionality of the limit switch.

Cost Considerations:

While cost should not be the sole determining factor, it is important to consider the budget for your project. Compare prices and features among different limit switches to find the best balance between cost and performance. Remember to prioritize quality, reliability, and compatibility with your application requirements over solely focusing on the price.

In conclusion, selecting the right limit switch involves considering factors such as environmental conditions, operating speed and force, actuator type, contact configuration, electrical ratings, mounting and connection options, safety and certification, reliability and durability, application-specific features, and cost considerations. By carefully evaluating these factors and choosing a limit switch that aligns with your specific needs, you can ensure optimal performance, safety, and functionality in your industrial applications.

Product Training Modules
NGC Series Limit Switch - Honeywell
Detect Switches - Copal Electronics
Electromechanical Switch Technology - Honeywell
Snap Switches - Omron
Sub-Miniature Snap Switches - C&K
DS Door Interlock Switch - C&K

If you have any general questions on the specifications for selecting Limit Switches, please reply using the button below. If you have questions on specific Limit Switches please post those questions in the Electromechanical Switches category.

Selecting the right limit switch is essential to ensure proper functionality and safety in various industrial applications. Limit switches are electromechanical devices used to detect the presence or absence of an object and provide feedback to control systems. They are commonly used in automation, manufacturing, and process control systems to monitor and control the movement of machinery and equipment. In this guide, we will outline the key factors to consider when selecting a limit switch.

Environmental Conditions:

The first consideration when selecting a limit switch is the environmental conditions in which it will be used. Different environments can pose challenges such as extreme temperatures, humidity, dust, vibrations, or exposure to chemicals. Ensure that the limit switch is designed to withstand the specific environmental conditions of the application. Look for switches with appropriate environmental ratings, such as IP (Ingress Protection) ratings for dust and moisture resistance, or NEMA (National Electrical Manufacturers Association) ratings for environmental protection.

Operating Speed and Force:

Consider the operating speed and force required for your application. Some limit switches are designed for high-speed applications, while others are more suitable for slower or heavy-duty operations. Determine the speed at which the object or machinery will be moving and select a limit switch that can respond accurately and reliably within that speed range. Similarly, consider the force or pressure that the switch will encounter and ensure it can handle the required load.

Sealed Plunger Actuator Limit Switch

Actuator Type:

Limit switches come with different types of actuators, which are the mechanisms that make physical contact with the object being sensed. Common actuator types include plunger, roller lever, whisker, rod lever, and spring-loaded. The choice of actuator type depends on factors such as the shape, size, and movement of the object to be detected. Consider the physical characteristics of the object and select an actuator that will provide reliable and consistent contact.

Contact Configuration:

Limit switches offer different contact configurations, including normally open (NO), normally closed (NC), and changeover (CO) contacts. The contact configuration determines the state of the switch when it is not actuated and when it is actuated. Select the appropriate contact configuration based on the requirements of your application and the desired behavior of the control system.

Electrical Ratings:

Evaluate the electrical ratings of the limit switch to ensure compatibility with your electrical system. Consider factors such as voltage, current, and maximum switching capacity. Ensure that the switch can handle the electrical load and voltage levels required by your application. Pay attention to the maximum switching capacity to prevent damage or premature failure of the switch when handling high currents or voltages.

Mounting and Connection Options:

Consider the mounting and connection options available for the limit switch. Common mounting types include panel mount, surface mount, and DIN rail mount. Choose a mounting option that suits the specific installation requirements and the available space. Additionally, consider the connection options, such as screw terminals or quick-connect terminals, and select the one that is most convenient for your wiring setup.

Safety and Certification:

If your application involves safety-critical functions or compliance with specific industry standards, ensure that the limit switch meets the necessary safety and certification requirements. Look for switches that are certified by recognized organizations or comply with industry standards such as UL (Underwriters Laboratories), CE (Conformité Européene), or IEC (International Electrotechnical Commission).

Reliability and Durability:

Reliability and durability are crucial factors when selecting a limit switch. Look for switches from reputable manufacturers known for producing high-quality and reliable products. Consider the expected operational lifespan of the switch and any maintenance requirements. Additionally, check for features such as built-in surge protection, self-cleaning contacts, or sealing options to ensure long-term reliability and minimize downtime.

Application-specific Features:

Depending on your specific application requirements, consider any additional features or functionalities that may be beneficial. For example, some limit switches offer LED indicators for visual status indication, adjustable sensitivity for fine-tuning, or wiring options for ease of installation. Assess your application needs and identify any additional features that can enhance the performance and functionality of the limit switch.

Cost Considerations:

While cost should not be the sole determining factor, it is important to consider the budget for your project. Compare prices and features among different limit switches to find the best balance between cost and performance. Remember to prioritize quality, reliability, and compatibility with your application requirements over solely focusing on the price.

In conclusion, selecting the right limit switch involves considering factors such as environmental conditions, operating speed and force, actuator type, contact configuration, electrical ratings, mounting and connection options, safety and certification, reliability and durability, application-specific features, and cost considerations. By carefully evaluating these factors and choosing a limit switch that aligns with your specific needs, you can ensure optimal performance, safety, and functionality in your industrial applications.

If you are looking for more details, kindly visit Tz-8107 Limit Switch.