The pushbutton switch is an element of electrical equipment that is in high consumer demand and is found almost everywhere. One of its main purposes is the ability to control the flow of electrical energy by pressing a special button. Pushbutton switches KE, VKI, VK and others are considered to be the most exploited.
Types of pushbutton switches
The push-button switch is designed for use in electrical circuits with alternating current in the network, at voltages up to 380V. According to the control method, lighting switches of this type are divided into:
- push;
- rotary;
- combined (you need to press them to turn on the lighting, and turn them to control the light level).
Scope of pushbutton switches
Most often, pushbutton switches are used in household appliances and mobile lighting fixtures. They are included ina complete set of control panels, cabinets in stationary installations, panels. Special operating conditions for push-button switches are not needed, because during operation the temperature range can be from - 60 to + 40 degrees with relative humidity up to 100%. They can be used for outdoor and indoor installations, in chemically active environments, hazardous areas, in the oil and gas industry and other industries.
There are quite a few models designed to control the main lighting in the room. They look like neat pushbuttons.
Latching and non-latching pushbuttons
Switches of this type can be:
- fixed;
- without fixation.
Push-button switch without fixation implies manual control. It works as long as the person holds the button. Such models are often used for control panels, in which their main advantages are best manifested - maximum protection against accidental activation and compactness. This is practically the only type of device that has manual control. In the on position, it is simply impossible to accidentally leave it.
Push-button switch with fixation is removed from the working state only by repeated pressing. This type of device is considered more common, because one person can control a large number of current consumers.
Push-button design featuresswitches
These controls, in terms of variety of colors, designs and shapes, are very little inferior to rocker switches. If you wish, you can choose a model with or without lighting, find products in modern, retro style, and so on.
Push-button switches of the usual design are made, as a rule, in plastic cases, due to which these products have a low cost. If you handle them carefully, they can last for quite a long time, while maintaining many thousands of switching cycles. The push-button switch with fixation for greater convenience of users is supplemented with a light indicator indicating the status of this device (off or on). If similar products will be used in difficult conditions, it is recommended to purchase them in an anti-vandal design, because they have excellent mechanical strength.
If necessary, the keys and buttons of the switches can be covered with a splash-proof cap, which will significantly extend the life of the device and reduce the risk of a short circuit.
The cost of products depends on their performance and design features. For example, a non-latching push-button switch will cost a little less than its counterpart. The difference in price between products in the usual and special or anti-vandal versions will be quite noticeable.
Connection
The circuit of pushbutton switches is quite simple. Their main nodes are:
- fixed contacts;
- bridge, which is equipped with movablecontacts;
- spring for bridge return.
The principle of connecting products is the same as for keyboard analogues - phase closing / opening.
Push-button switches VK16-19
Products of this series are used to control electrical circuits with alternating current with a frequency of 50 and 60 Hz, as well as with voltage up to 220V. In addition, the products are used for circuits with direct current and voltage not exceeding 220 V. The push-button switch VK16-19 comes with a built-in signal lamp, which is necessary for light indication in the actuation position.
Application
Switches of this type are mainly used to complete consoles, panels, posts and control cabinets in various stationary installations, mill equipment, rolling machines, automation systems and electric trains.
How the device works
The operation system is quite simple. When you press the starter, the contacts switch. In models that come without a latch, when the force is removed, the latch returns to its original position. At this point, the contacts are switched. In push-button switches with mechanical fixation, the pusher remains in the pressed state when the force is removed and only when pressed again returns to its original position.
In products with electromagnetic fixation, when pressed, the electromagnet is turned on, and the pusher is fixed in the pressed position. When turned off, it will return to its original position.
SwitchesKE
This is a unified device designed for switching AC and DC electrical circuits.
Hardware Features
Pushbutton switch KE is used in almost all areas of industry. Such equipment is purchased by both mechanics for machine tools and electricians for control panels. The products of this series are used in mobile installations or stationary equipment.
The composition of such a device includes:
- unified contact elements;
- control device;
- fasteners.
In a circuit breaker, the drive is a device responsible for the tightness of the connection and the pusher. It is equipped with a signal lamp that notifies the personnel about the working condition. The NO/NC contacts are not connected to each other. When you press the working pusher, the traverse moves, which opens / closes the contact.
Before installing the product, you need to remove the front ring, tighten the slotted nut to the stop so that the switch does not turn. The button is pushed into the hole with the reverse side so that there is a tendril of the ring. Then, while holding the device, you need to screw the front ring all the way along the axis, run the power wires and connect to the equipment.
Push-button switches with blocking VKI
This is a device that is designed for rare switching of single- and three-phase loads, both inductive and active in nature (in electric motors,heating and lighting devices). The scope of switches of this series is very diverse. They are used in electrified construction machines and mechanisms (small volume concrete mixers, power tools, street lighting circuits, mobile fan heaters, pumps, compressors, etc.).
When using such a device, additional means of protection against overload and short circuit should be provided, since the VKI push-button switch does not have built-in overcurrent protection. These can be circuit breakers or fuses. Products of this series consist of a plastic base divided into 3 parts, each of which has contact brass holders directed towards each other. On the one hand, they are connected to the conductors of the network and the load, and on the other hand, to the contacts.
In order for the interlocked pushbutton switch to work as long as possible, certain rules must be followed during operation:
- Ambient temperature should not exceed 50 degrees.
- The switch must not be located in an explosive area. The room should not contain a high concentration of dust, as dust greatly reduces the performance of the device.
- Vibration load must not exceed the allowable frequency (60 Hz).
- It is recommended to avoid exposure to direct sunlight.
- Push-button switches with blocking of the VKI series can occupy any position in space.
Only if you follow these recommendations, you can confidently use this or that device.
