Button switch appearance
1. The structure of the push button switch
The structure of button switch consists of button cap, return spring, fixed contact, movable contact, It is composed of shell and strut connecting rod.
Normally open contact (moving contact): refers to the contact in the original state (the electrical appliance is not subjected to external force or the coil is not energized), the fixed contact and the movable contact are separated.
Normally closed contact (moving and breaking contact): refers to the contact in which the fixed contact and the movable contact are in a closed state in the original state (the electrical appliance is not subjected to external force or the coil is not energized).
Normally open (moving and closing) button switch, when not pressed, the contact is disconnected, when pressed, the contact is closed and connected; when released, the button switch is reset and disconnected under the action of the return spring. In the control circuit, the normally open button is often used to start the motor, also known as the start button.
The normally closed (moving off) button switch is the opposite of the normally open button switch. When it is not pressed, the contact is closed, and the contact is disconnected when it is pressed; when the hand is released, the button switch is reset and closed under the action of the return spring. . The normally closed button is often used to control the motor to stop, also known as the stop button.
Composite button switch: a button switch that combines normally open and normally closed button switches into one, that is, with normally closed contacts and normally open contacts. When not pressed, the normally closed contact is closed and the normally open contact is open. When the button is pressed, the normally closed contact will be opened first, and the normally open contact will be closed; when released, the button switch will first open the normally open contact under the action of the return spring, and then close the normally closed contact. . Composite buttons are used in interlock control circuits.
Installation and use of pushbutton switches
(1) When the buttons are installed on the panel, they should be neatly arranged and arranged in a reasonable manner. They can be arranged from top to bottom or from left to right according to the sequence of starting the motor:
(2) The installation and fixation of the button should be firm, and the wiring should be reliable. Apply a red button to stop, green or black to start or power up, don't get me wrong.
(3) Due to the small distance between the button contacts, short-circuit faults are prone to occur if there is oil pollution, so the contacts should be kept clean.
(4) The button board and button box on which the button is installed must be made of metal, and try to connect them with the general grounding bus of the machine tool. For the hanging button, a special grounding wire must be provided, and the metal pipe shall not be used as the grounding wire.
(5) When the button is used in high temperature occasions, it is easy to cause the plastic deformation and aging, which will lead to loosening, which will cause the short circuit between the wiring screws.
(6) The button with indicator light is easy to deform the plastic lampshade due to the heat of the bulb, so the voltage of the bulb should be reduced to prolong the service life.
(7) The "stop" button must be red; the "emergency stop" button must be a red mushroom head; the "start" button must have a protective retaining ring, and the protective retaining ring should be higher than the button head to prevent Accidental triggering makes electrical equipment malfunction.
(1) When the buttons are installed on the panel, they should be neatly arranged and arranged in a reasonable manner. They can be arranged from top to bottom or from left to right according to the sequence of starting the motor:
(2) The installation and fixation of the button should be firm, and the wiring should be reliable. Apply a red button to stop, green or black to start or power up, don't get me wrong.
(3) Due to the small distance between the button contacts, short-circuit faults are prone to occur if there is oil pollution, so the contacts should be kept clean.
(4) The button board and button box on which the button is installed must be made of metal, and try to connect them with the general grounding bus of the machine tool. For the hanging button, a special grounding wire must be provided, and the metal pipe shall not be used as the grounding wire.
(5) When the button is used in high temperature occasions, it is easy to cause the plastic deformation and aging, which will lead to loosening, which will cause the short circuit between the wiring screws.
(6) The button with indicator light is easy to deform the plastic lampshade due to the heat of the bulb, so the voltage of the bulb should be reduced to prolong the service life.
(7) The "stop" button must be red; the "emergency stop" button must be a red mushroom head; the "start" button must have a protective retaining ring, and the protective retaining ring should be higher than the button head to prevent Accidental triggering makes electrical equipment malfunction.
