Before using the emergency stop button, we need to do some relevant understanding, so that we can reduce the wrong operation in the process of use.
1. In some transmission parts in industrial safety, protection measures must be added to the machines that directly or indirectly cause harm to the human body when abnormal conditions occur. The emergency stop button is one of them. Therefore, when designing some machines with transmission parts, the function of emergency stop button must be added, and it must be installed on the surface of the machine that can be easily pressed by personnel, and there should be no obstructions.
2. The "stop" button must be red; the "emergency stop" button must be a red mushroom head type; the "start" button must have a protective retaining ring, which should be higher than the button head to prevent accidental touch and electrical equipment from malfunctioning.
3. The emergency stop button switch only needs to be directly pressed down to quickly stop the whole equipment or release some transmission parts. To start the device again, you must release this button, that is, you only need to turn it clockwise about 45° and then release it.
4. After connecting the emergency stop button to the circuit, the bottom two contacts correspond to the control loop.
The connection method of 380V is: power phase A connects to any contact of emergency stop button → another point of emergency stop button connects to a certain point of control loop → another point of control loop connects to phase B of power supply. If it can't work, don't move the lead of the emergency stop button, swap the two points of the control loop, some contactors have different directions.
The connection method of 220V is: connect the live wire to any contact of the emergency stop button → connect another point of the emergency stop button to a certain point of the control loop → connect another point of the control loop to the zero line.
1.Wrong use of the normally open point of the emergency stop button:
Some sites will use the normally open point of the emergency stop button and then use the PLC or relay to achieve the purpose of emergency stop. This wiring method cannot immediately cut off the fault when the emergency stop button contact is damaged or the control circuit is disconnected. The correct approach is to connect the normally closed point of the emergency stop button to the control circuit or main circuit, and immediately stop the output from the actuator at the moment the emergency stop button is pressed.
2.Wrong use occasion:
The emergency stop button is only used when there is an accident in operation, and some maintenance personnel perform maintenance work after pressing the emergency stop button. In this case, once the emergency stop button is damaged or other personnel will turn the emergency stop button without knowing it Resetting may cause significant loss of life and property. The correct approach should be to perform maintenance after power failure and identification.
3.Wrong usage habits:
In some scenes, especially those with low frequency of use of emergency stop buttons, regular inspections of emergency stop buttons may be ignored. Once the emergency stop button is blocked by dust or malfunctions and is not discovered in time, it may not be able to cut off the danger in time when the fault occurs, thus Cause heavy losses. The correct way is to check the emergency stop button regularly to avoid accidents.