The role and characteristics of the emergency stop switch is that when an emergency occurs, people can quickly press the button to achieve protection.
In all kinds of factories, some large and medium-sized machinery and equipment or electrical appliances can be seen on the eye-catching red button, the standard should be marked with "emergency stop" meaning the same red font. This button can be collectively referred to as the emergency stop button.
This button is simply pressed straight down. This button can be pressed directly downward to quickly stop the entire machine or to release some parts of the drive. In order to start the equipment again must release this button, that is, just clockwise rotation of about 45 ° after release, the part will be pressed up. That's "release".
Expanded Information
The basic function of the emergency stop button is to stop the machine in case of emergency, to avoid mechanical accidents or personal accidents. However, due to the long time running of the machine, the line, especially the emergency stop line part, may cause fault disconnection.
Then, if the emergency stop button using normally open contacts, the emergency stop part of the line failure will not be found, if the time to use the emergency stop button and then found that it has been too late.
While using normally closed contacts, when the emergency stop part of the line failure, the most will cause the machine to stop, the loss will be relatively small.
It is based on the above reasons, in the design of the electrical control system, the emergency stop button is also best to use normally closed contacts.
Baidu Encyclopedia - Emergency Stop Button