D4N-322G

Snap Action, Limit Switches

The D4N-322G snap action and limit switch is a mechanical type switch widely used in industrial automation due to its advantages and reliability. It is a fundamental component of electronic circuits in automation systems and machines, for example, for controlling machinery and equipment, for actuating sections of production lines and for industrial applications such as lift and load cell applications. The switch features separate actuator and contact blocks that allow it to be used in very tight spaces and it is suitable for use in heavy-duty applications.

Mechanism

D4N-322G snap action and limit switches are designed with a reliable, low-force mechanism, which operates with a snap action when actuated. Its contact system provides bounce-free switching and an adjustable over-travel feature for sensor accuracy and longer switch life. The snap action feature of the switch is achieved by the interaction of the actuator and contact mechanisms, in which a plunger moves in the switch and pushes against the contact block. This action is initiated when the contact block is pushed or pulled by applying a force to a flexible actuator including an over-travel adjustment screw. The plunger then either opens or closes each contact as it is pushed in or pulled out.

Contact System

The D4N-322G snap action limit switch is designed with contact blocks made of copper-beryllium alloy that act as the switching elements. The contacts are usually separated into normally open (NO) contacts and normally closed (NC) contacts. These contacts are designed to be able to handle current loads up to 10A, and they are operated by an adjustable plunger mechanism located within the switch. In terms of mounting, the D4N-322G can be mounted on a panel or on a bulkhead.

Additional Features

In addition, the D4N-322G snap action and limit switch features a positive opening option, allowing a positive opening of the switches’ interconnected contacts that separates the contacts physically. This prevents the contacts from touching in case of an electrical or mechanical shock. It also features a “DiSin” protection, which helps to protect the switch from dust and dirt, ensuring long life.

Applications

The D4N-322G snap action and limit switch covers a wide range of applications, including elevators, weigh scales, process control, and material handling. It can be used to measure position and speed of a motor, detect errors in machine cycles, and to trigger signals in emergency stop applications. It can also be used in robotics, integration of machines, and conveyor systems.

Working Principle

The working principle of the D4N-322G snap action and limit switch is based on the interaction between the actuator and contact mechanisms. A plunger moves in the switch to make contact with the contact block. When a force is acted upon the flexible actuator, the plunger is pushed in or pulled out of the switch, thus opening or closing the contacts. The adjustable over-travel feature further ensures that the plunger is able to move to the desired position without completely disconnecting the contact blocks.