I was searching this weekend on how to add an emergency stop to my project and found a solution that worked but during my search I came across a post where they were using jumpers on the Em. stop button and it had symbols on the jumpers I didn't understand and couldn't really search it in the effort to try and learn something so I thought maybe somebody could venture a brief explanation and I could further research things on my own.
Here is a photo of what I saw, they are using jumpers with some type of switch?
appreciate any knowledge you have to offer.
The E Stop locks in the off position when pressed and removes the possibility of the equipment, usually a contactor or relay, being re energized.
The schematic shows a button with a mushroom head that will be the color red, not all stop buttons lock in the off position.
The stop button is wired in series with the control equipment (relay) coil and any additional stop devices (buttons or switches) will also be wired in series with the control equipment coil. In your schematic the two wires for the stop button would connect to terminals 1 and 20.
Terminals 2 and 20 may or may not be utilized as perhaps an indicator or input to a controller such as a PLC or microcontroller.
As noted stop buttons are normally closed switches connected in series, normally closed with the chances of a damaged control circuit failing in a safe/open condition for example a broken wire. Start push buttons are wired normally open and connected in parallel.
Thanks for the info everybody.
I was guessing it was some type of switch because of the symbol but since I'm pretty new to schematics I thought I would ask.
