Limit Switch for Linear Actuators: End-of-Travel Control
A limit switch for a linear actuator can mean an internal end-of-travel device built into the actuator, an external mechanical switch placed along its moving path, or a signal input to the actuator controller. These are not interchangeable. Start with the actuator's own wiring diagram and operating limits, then decide what event must stop extension or retraction and how the controller will respond. A limit switch is a sensor and circuit element; it must not be treated as a mechanical hard stop or assumed to be a complete safety function. LEMA LZ8 product-library original showing two miniature limit-switch actuator forms. The photo is a product example, not a claim that this switch is a pre-wired linear-actuator kit. A distinct LZ8-series spring-rod product view. The target must match the chosen actuator head's specified direction and travel. First decide whether the actuator already has travel limits Read the exact actuator model documentation before adding a switch. Some linear actuators have built-in end switches, adjustable internal limits, encoder feedback or a controller that stops motion at configured positions. Others provide only motor power leads and expect the equipment designer to provide external control. The product name or stroke length alone does not tell you which arrangement is present. Draw the operating chain from the actuator to the machine controller. Identify which device senses the endpoint, what signal changes, which circuit interrupts or inhibits motion, and how the actuator is allowed to move in the opposite direction after reaching a limit. An internal end switch may open one motor direction while allowing reverse motion, or it may report state to a controller. An external switch may instead send a low-current input to a relay,...
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