Confused about limit switch types

Thread Starter


Joined May 22, 2020
I am trying to draw up a circuit diagram for a electric window opener.

There will be two limit switches connected to a motor controller so that the motor will stop when the limit switches (one for window position position and one for the closed position) are trggered..

The controller has the limit switch terminals built-in:

Which type of limit switch should I get that will work with this controller to my needs? The fwd and rev buttons will be operating in toggle mode to open and close the window. When the open limit is triggered, the motor will stop. The user s has the ability to close the window by pressing the close button from the remote and vice versa.

Does that means that I just need two 2p limit switches connected to the controller?


Joined Jun 4, 2014
I would venture that the limit switches need to open when the limit is reached. The unit is shipped with the links shown in the picture below and the text says to remove these links if you want to use limit switches. Therefore the motor can run when these points are linked.


Joined Sep 11, 2014
Hi Teetee543,

Fail-safe controls utilize 'NO' contacts to enable a system and 'NC' contacts to disable the same.

Here are some examples
  • 'NO' push-button switch contact to start an actuator (motorized, hydraulic or pneumatic) and 'NC' to stop it.
  • 'NO' limit switch contact to confirm the position of an actuator.
  • 'NC' limit switch contact to stop an actuator.
Swapping the above 'NO' contacts with 'NC' and vice-versa would cause an unintended start / prevent an intended stop in the case of a 'wire break'.