Sometimes you may not want to use the entire stroke length of a linear actuator, to restrict the travel distance you will need our external limit switch.
How external limit switches work
External Limit switches are spring loaded buttons that when pressed open / close the circuit, stopping the motor from spinning any further. These switches have 3 terminals (NC, NO and COM). By connection the external limit switches to the limit control terminals of remote control switch.When the actuator collides with the external limit switch, cut off the power supply of the electric linear actuator motor.
In-built limit switches
All our linear actuators have internal limit switches at the fully extended and retracted positions. These limit switches ensure that when you fully extend (or retract) the actuator it will automatically shut off preventing the motor burning out and/or doing damage to the body of the actuator. However, these limits not adjustable.
If you want to:
Limit both extension and retraction
Then you will need to mount external limit switches.
Installation and Connection External limit switches
Firstly mount your actuator in your application and determine where your upper and/or lower limits need to be. Using small screws or bolts attach one (or two) of the limit switches so that the actuator will collide with them when it reaches your maximum/minimum desired position.
Connect the normally closed terminal and common terminal of the external limit switch to the limit control terminals of remote control switch as shown in the wiring diagrams below.