The button switch can complete basic control such as start, stop, forward and reverse rotation, speed change and interlock. Usually each push button switch has two pairs of contacts. Each pair of contacts consists of a normally open contact and a normally closed contact. When the button is pressed, the two pairs of contacts act simultaneously, the normally closed contact is disconnected, and the normally open contact is closed.
In order to indicate the function of each button and avoid misoperation, the button caps are usually made of different colors to show the difference. Its colors are red, green, black, yellow, blue, white and so on. For example, red means stop button, green means start button, etc. The main parameters, type, installation hole size, number of contacts and current capacity of the contacts of the push button switch are detailed in the product manual.
When the button is not affected by external force (ie static state), the opening and closing state of the contact is divided into the start button (ie the normally open button), the stop button (ie the normally closed button) and the compound button (ie the normally open and normally closed contacts are combined as integrated button). For the start button, the contacts are closed when the button cap is pressed, and the contacts are automatically disconnected and reset when released; the opposite is true when the button is stopped, the contacts are separated when the button cap is pressed, and the contacts are automatically closed and reset when released. The composite key is that when the key cap is pressed, the bridge-type moving contact moves downward, so that the normally closed contact is disconnected first, and then the normally open contact is closed; when the key cap is released, the normally open and normally open contacts are closed first. After breaking and resetting, the normally open contact is closed and reset again.
(1) When installing the buttons on the panel, they should be neatly arranged and arranged in a reasonable manner, which can be arranged from top to bottom or from left to right according to the sequence of starting the motors:
(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 a high temperature occasion, 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.
