Safety Circuits play an important role in industrial automation. Their main purpose is to protect the user from any physical harm. However, they keep the equipment from getting damaged as well. Over the years, safety circuits as well as standards evolved, became more stringent and continue to push manufacturing to the state of zero injuries.
This is a companion discussion topic for the original entry at https://www.solisplc.com/tutorials/allen-bradley-guardmaster-safety-relay-wiring-tutorial