are special devices that are used for the purpose of remote control various electrical installations and devices, machines and machine tools. Basically, buttons and posts are used with electrical equipment where electric motors are drives.
Thanks to buttons and push-button stations, the operator is relieved of the need to climb onto the crane in order, for example, to move the hook to the right place. To accomplish this task, it is enough just to use one button. This is how machines, pumps and other large equipment are controlled.
The necessary buttons and posts are located at the workplace in such a way that they form a single control panel designed to solve certain problems at a particular enterprise.
What is a button?
Pushbuttons are an electric apparatus, which includes a pushbutton element and a drive element. The main purpose is manual remote control of equipment and devices. Buttons are used in AC electrical circuits, the maximum voltage of which is 660 V, as well as in DC circuits with a voltage of 440 V.
Blocks are divided into two types:
- monoblock - the drive and contacts are in one block;
- two-block - the drive is mounted on a separate plate, and the button is located on under the drive.
After the pressure is released, the drive element returns to initial position. But among the huge number of modern buttons and push-button posts, there are those that do not have a self-return, but are equipped with a mechanical or electromagnetic latch. Modern models of buttons are equipped with moving contacts made of silver or cermet. The type of these contacts is a bridge with a double break in the electrical circuit.
The safety of work is ensured by the fact that the pushers of the stop command buttons protrude 3-5 mm above the remote control cover. The start buttons, in turn, are recessed into the cover to the same depth.
Modern buttons and push-button posts differ in the degree of protection from environmental influences. Thus, there are buttons of an open type, as well as protected from dust and moisture.
What is a push post?
A station or button post is a number of different buttons that are combined under a single shell.
The purpose of the push-button station is to turn off and turn on electrical equipment, change the direction of rotation of electric drives, for emergency shutdown of devices, etc.
Push-button stations are made in various cases and with a different number of buttons, which directly depends on the tasks assigned to the stations. There is a bottom feature - push-button posts are not used in chains high voltage at the same time they can work with high-voltage equipment. The operation of push-button posts occurs in AC voltage circuits up to 600 and DC up to 400 V. The starter performs the role of switching power circuits, which, in turn, is controlled by a push-button station. Let's give an example: a magnetic starter controls the connection of an asynchronous type electric motor to the electrical network (either directly or in reverse); the starter is controlled by the post.
The number of buttons in a button post is determined by the number of consumers, as well as their number. Thus, the push-button station can be two-button and multi-button. The simplest version of the post is two buttons (“start” and “stop”). It also happens that one button is used.
The main element of any button post is a push button. These buttons are divided into two types: with the function of self-return and with the possibility of fixation.
Self-return pushbuttons return to their original position using a special spring. That is, when you press the "stop" button, the "start" button returns to its original position. If the push button is fixed, then the contacts will open only when pressed again.
Button stations of this type have a wide range of applications. They often control magnetic starters, while not supplying current directly.
The body of the push-button post is made of either plastic or metal. The choice of material directly depends on the conditions in which operation is implied, as well as on the degree of safety. The buttons differ in shape and color. The color scheme has already become classic. So, the stop buttons are usually red, and the start buttons are green. The shape of the buttons can be recessed, mushroom-shaped, cylindrical.
The choice of push-button posts that are currently on the electrical market is very extensive. But at the same time, all devices operate on the same principle. The most popular posts are "PKE" models. They are mainly used in woodworking machines, on conventional milling machines.
A series of PKU posts is a special line for operation in an explosion-proof environment, where the content of gases and dust is minimal.
Explosion-proof posts are devices "KPVT" and "PVK". They are mainly used in the coal industry, etc.
PKT stations are posts for controlling overhead cranes and beam cranes.
In order to be able to control a variety of mechanisms at a distance, special devices are used. Basically, for this purpose, a push-button control post for 2 or 3 buttons is used.
Description and design
The control post is designed for switching electrical circuits various devices and electromagnetic starters of machines. This device allows you to provide remote control at work and at home. Exist different kinds push-button switches, which are classified depending on the area of \u200b\u200buse and the characteristics of the working network (telpher, explosion-proof, etc.).
Photo - simple circuit postsThe design of posts also depends on their type and use. Consider a push-button control post PKE 222 2 for 2 buttons, which has a very simple control scheme. This switch is installed in niches, therefore it is enclosed in a plastic case with special pushers. The mechanism is sealed, protection level IP40, the main parts are two working contacts isolated from each other. At the same time, there is a similar imported device with IP54 protection. Its feature is the presence of a rubber gasket between the pusher and the working contact. In both types of device, an additional gasket is mounted between the wall (or other mounting plane) and rear panel. Main Feature This model is the presence of holes and an additional casing where the wires are inserted.
Photo - PKE 222 2 The principle of operation is based on the operation of a simple impulse relay. When the button is pressed, the contact closes and the switched device is turned off, respectively, when pressed again, this contact opens and the device controlled by the post turns on.
Photo - diagram of a simple contactor Video: FPB series buttons
Types
Exist different types button posts, consider specifications and a description of the most popular of them.
Push-button explosion-proof or emergency post PVK 1,2,3 is used for remote control of vehicles (both land and sea). Due to their rather wide action, such devices are often also used to control drives of stationary machines (machine equipment).
Photo - PVC Specifications:
- Initial voltage - 127 Volts;
- Network frequency - 50 Hz;
Marking is standard, for example, PVK 21U5:
- X1 - the number of pushers above the contacts (in our case 2);
- X2 - protection;
- X3 - climatic version according to GOST 15150-69 (there are options U, HL, OM or T, in this device- "U");
- X4 - installation type.
Post telfer with a key push-button type PKT 60. With the help of a starter of this type, the operation of various traction mechanisms is controlled. This is mainly a crane, an elevator escalator, beams, etc. This manual post is equipped with a special indication that allows you to control the mushroom button and direct it in the right direction.
Photo - PKT 60 6 buttons An open-type push-button post with fixation PKU 13 can be mounted on closed and open areas of various mechanisms (cranes, machine tools, etc.). The system operates on a standard network of 660 (440) Volts with a frequency of not more than 60 Hertz. Used for installation on pumping stations, triggers (for example, in the port), etc.
Photo - PKU 13 Push-button explosion-proof station KU 92 is necessary to control the operation of dynamic and stationary machines in any conditions. The key feature is the protection level IP 54 and explosion protection 1ExdIIBT5. The device in a plastic case is equipped with an inlet with a seal (rubber gasket). A contact control drive is also enclosed inside the housing. The certificate of quality conformity indicates that armored power cable, as well as pipe cords with rubber seals, can be connected to the working contacts.
Photo - KU 92 It is very easy to understand the indication of this button post: 1 button is “STOP”, 2 buttons are “START”, “STOP”, 3 buttons are “FORWARD”, “BACK”, “STOP”. The choice of climatic modifications is possible. This is U - moderate, HL - protected from the cold, T - tropical.
The push-button station of the KP-101 series of anti-emergency execution, is placed in the ABS plastic case. This allows you to install the device in various conditions. Thanks to multiple spacers between pushers, contacts and cable insertion holes, the device has increased protection against dust. Mainly used to control lighting systems.
Photo - KP-101 The PK-221/9 starter is a modern fire station, which is necessary for switching networks up to 380 Volts with a standard frequency of 50 Hertz. The manufacturer equipped it with 16 buttons, the contacts of which are completely isolated from each other. They are used in domestic and industrial conditions, especially often used in automatic lines. Also key feature is a metal case, due to which the device is protected from ignition and the spread of fire.
KMZ is an analogue of the more outdated PKU model, it is also called KM. The designation is deciphered as follows:
K - push-button, M - magnetic post, Z - protected from explosion, dust and fire. This is followed by the number of buttons (1, 2, 3) and the climate version. The manufacturer has provided maximum protection for the working elements, so the post can be installed in an external control system. Magnetic devices are considered the most durable and fastest.
Photo - KMZ connection diagram Devices of the KE series (KE-011, 031, KE-91-1 ExdIIBT5-U2 and others) for connection to AC and DC networks. Depending on the type of execution, they can have one button (red mushroom), two or three. Max voltage for this series - 660 volts at a frequency of 60 hertz. All KE devices are divided into groups:
- With mushroom type pusher;
- With cylindrical valve;
- With signal lamp or illumination under explosion-proof glass.
In addition to domestic models, imported push-button stations are also used (Schneider Electric, ABB - ABB, Legrand, IEK), which can be bought in official stores. In particular, this is a firefighter XAL (Harmony XALD, XALK). Dimensions allow to mount devices in control rooms or on various moving parts of devices under control. Sometimes several models are used, which, when assembled, represent a control launch point.
The price of a button post depends on its type, brand and area of use (the cost can vary from several hundred rubles, but sometimes the price list reaches tens of thousands). When buying, be sure to check the passport of the device, its service life and warranty.
For remote control of various electrical appliances and machines, control buttons and push-button posts are used. Most often, with the help of these tools, they control the equipment where electric motors are used as drives. So, the operator does not need to climb onto the crane-beam to bring the hook to the right place on the workshop, instead, he just needs to press the appropriate button on the control panel, and the crane itself will approach where the operator indicates.
The power supply and operating modes of machines, fans, pumps, etc. are controlled in a similar way. Buttons and push-button stations can be located at the operator’s workplace, forming a specialized console for solving specific tasks related to equipment control at a given enterprise.
Button - an electric command device, consisting of a push-button (contact) and drive elements and intended mainly for manual remote control of electromagnetic devices.
Buttons are used in AC circuits with a voltage of no more than 660 V and direct current - no more than 440 V. There are two types: monoblock, in which the contact element and the drive are mounted in a single block, and two-block, in which the drive (pusher, handle, lock with a key) is installed on a separate plate, and the button element is mounted on a base under the drive element. Buttons can have from 2 to 8 contacts, and the number is normal open contacts usually equal to the number of normally closed.
After the pressure on the drive element stops, it, together with the contacts, returns to its original position under the action of the return springs. There are buttons without self-return - with a mechanical or electromagnetically controlled latch. Modern button designs use bridge-type moving contacts with a double circuit break. The contact material is silver or cermet compositions.
The continuous mode current and the switched alternating current do not exceed 10 A. The pressing force on the button drive is 0.5 - 2 kg. For safety purposes, the pushers of the buttons that execute the “stop” command protrude 3-5 mm above the level of the console cover where they are installed, and the buttons that execute the “start” command are recessed at the same distance.
According to the degree of protection from the influence of the environment, there are buttons of open, protected and dust-proof execution. Several buttons built into one shell or installed on one cover form a button post (station).
Pushbutton stations are designed to turn on and off electrical devices, to change the direction of rotation of drives in devices, for manual emergency shutdown of equipment in emergency situations, etc. - depending on the purpose of a particular electrical equipment.
In general, it can be noted that for various tasks, push-button posts are made in different cases and with a different number of buttons, however, one feature is fundamentally important - push-button posts are not used in high-voltage circuits, they, of course, can control high-voltage equipment, but they themselves work in circuits with voltage up to 600 volts AC or up to 400 volts DC.
Often, the current through the push-button post is not the operating current of the installation. Switching of power circuits is carried out by a starter, but a push-button post controls the starter.
For example, a magnetic starter controls the connection to the network of an asynchronous motor directly or in reverse, and the operator controls the starter using a three-button post: “start forward”, “start reverse”, “stop”. By pressing the "start" button, the normally open contacts of the starter are closed according to the direct start of the engine, and when the "start back" button is pressed, the contacts change their configuration to reverse. "Stop" - the starter opens the power circuit.
The number of buttons on the button post is determined by the purpose of consumers and their number. So, posts are two-button and multi-button. In its simplest form, there are only two buttons “Start” and “Stop”. And sometimes one button is enough, for example, installed on a lathe.
Buttons can be located in a metal or plastic case, which, in turn, is mounted on a more convenient place for operation. Separately, you can select posts for controlling crane beams (PKT posts - push-button hoist post).
The main element of the button post is the push button. Pushbuttons come in two types: self-returning and latching. Self-returning ones are pushed to their original state by a spring - the operator pressed the "Stop" button - the "Start" button returned to its original state, and those with a fixation - only after pressing again - until you press again - the contacts will not open.
An example of a push-button post with fixation is the popular two-button post: the "Stop" button is pressed - the contacts are open, the "Start" button is in a free state. The "Start" button is pressed - the contacts are closed, and the "Stop" button is in a free state. Such posts serve a wide range of applications, and they often control magnetic starters rather than supplying current directly.
Depending on the operating conditions and the degree of electrical safety, the material of the push-button post housing can be plastic or metal, and sometimes the buttons are simply installed without a housing on the outside of the device. As for the buttons themselves, they differ in shape and color. The shape is divided into: recessed, mushroom-shaped and cylindrical, and by color: the Stop buttons are characterized by red or yellow colors, and the Start buttons are blue, white, green and black.
The range of button posts on the market today is very wide, but in principle they all work on the same principle. Posts of the "PKE" (single) series are particularly popular. They can be found on woodworking machines, on simple milling machines, etc. These buttons are capable of directly switching currents up to 10 A at an alternating voltage of 660 volts.
Push-button posts of the PKE series are designated by numbers that can be deciphered. The first digit indicates the row in the series, the second - the method of installation (surface-mounted / built-in), the third - the degree of protection, the fourth - the material of the case (plastic / metal), the fifth - the number of controlled contacts, the sixth - the degree of modernization, the seventh - the climatic version in accordance with placement category.
Push-button control stations are devices of a rectangular or square configuration in a case made of durable plastic, plastic or metal, inside of which push-button controls are mounted. Functionally and structurally, the devices may differ slightly from each other, but their principle of operation is identical - the transportation of alternating current through voltage circuits with indicators up to 600 volts (frequency - up to 60 Hz). As a result, the operating mode of the connected units changes. The controllers can also be operated up to 400 V DC (settings can be changed in fixed or remote mode). The main scope of the devices under consideration is industrial sectors. The principle of operation of the device is the transfer of power in the control circuit of the electric motor.
Purpose and functionality
Industrial push-button control stations are designed for remote control of various devices and devices with electric motors. Most often they are used in control circuits of three-phase motors of synchronous and asynchronous action.
The use allows the operator of the ventilation unit to adjust the operation of the unit from his workplace, without climbing into the coverage area of the equipment. As a rule, push-button control posts are located on a common panel, the so-called common control post.
The main functions of the devices in question:
- Activation and deactivation of electrical appliances and apparatus.
- Carrying out a reverse (switching the direction of rotation of the rotor).
- Emergency shutdown of machines and other devices.
Operation in high-voltage circuits of the considered regulators is not provided.
Connection
Connection of push-button control stations and their subsequent operation is carried out using coils of magnetic starters, providing direct and reverse switching on of the motor. The control on the remote control is carried out by the buttons "Start", "Stop" ("Forward / Back").
When the Start-Forward pusher is activated, power is transmitted to the first magnetic starter through its coil, after which the group of contacts closes, providing power to the electric motor windings. When the "Start-back" function is activated, the second magnetic starter coil is blocked, while the normally open contacts close in parallel with the "Start-forward" mode.
Turning on the "Stop" key ensures that the electric motor is de-energized, while power is not supplied to both starters, the contacts are in an open state. When the reverse is activated, the operation of the contacts is similar to the start, only power is supplied to the second magnetic starter.
Peculiarities
Depending on the number of controlled consumers of electrical energy, push-button control stations can be two-button or multi-button. It should be noted that in the production of installation and electrical work, single buttons are used, which are installed by the user on any type of push-button switch.
The devices in question are installed in a metal or plastic case with mounting holes for fitting fittings at the place chosen as the main operational post. A separate category includes control panels for telphers (PKT), bridge hoists and overhead cranes with a ground type of control.
The main element of the push-button control station is the push button, which is a switching electrical fitting with manual control. Consider the types of pushers and the devices themselves, their differences among themselves, as well as features by application.
Types of pushers
The pushers used in the design of the push-button control post, the price of which varies from 300 to 800 rubles (depending on the type and material of the case), are divided into two categories:
- Self-return options. Such buttons return to their original position by means of a spring located on the pusher at the bottom.
- Fixed (self-retaining) models. Buttons of this type fix the contact tightly until pressed again.
The most widely used two-button modification, the pushers are painted in different colors. In the free position, the Start button has open contacts, and the Stop button has closed contacts. Pushers may differ in color and shape:
- The color of the lock button is usually red or yellow.
- Starter pushers are painted in black, blue, green or white.
- The shape of the buttons can be in the form of a mushroom, a cylinder, and also recessed into the case.
Types of remotes
There is a wide range of push-button controllers on the market today. Functionally, they are almost identical, they differ in brand, configuration and case material.
The PKE push-button control post is produced in Russia and is used to control industrial equipment. This series is mainly used in the schemes of metal-woodworking machines, as well as in the production of various mechanisms.
Operating characteristics of the device:
- The limit value of the switched voltage (alternating / direct current) is 600/400 volts.
- Switching current - 10 A.
- Operation cycles to the maximum - 5x10 ₆.
Push-button PKU control stations are designed for use in an environment protected from explosions, where the accumulation of a gas-dust mixture will not provoke a violation of the integrity and operability of the controller. The parameters of this electrical fittings are similar to those of PKE.
PKT
This type of push-button type control stations is designed for aggregation with electrical equipment of lifting devices such as electric hoists, overhead cranes and overhead cranes equipped with a manual ground control. As a rule, this type of controller is used in various production shops, warehouses, and special production facilities.
The characteristics of the operational and electrical plan are commensurate with those of the PKU and PKU versions. Also on the domestic market, Chinese-made electrical fittings are sold under the IEK marking. Its performance is completely identical to Russian counterparts. The price also does not differ much from identical domestic modifications.
Explosion-proof push-button control station
Domestic explosion-proof controllers with pushers in the letter designation have an additional index "B", for example, PVC or KPVT. Such devices are used in the control circuits of equipment that is operated in an explosive environment (mines, oil storage facilities, paint shops and similar industries).
Posts such as XAC-A (Germany) and KS (Poland) were widely used. Also in this segment, remote push-button electrical fittings are more often used.
In conclusion
PVK - push-button control station, which is used to control electrical equipment in an explosive environment. Analogues without index "B" are used in safer areas. The principle of operation of all regulators with pushers is identical, they differ in appearance and in the number of buttons. Models in a metal case are more durable and cost a little more. When choosing a post, one should take into account the features of its further operation and the compliance of the characteristics with the conditions of use.
Push-button control posts- devices that are produced in the form of a rectangular or square case made of durable plastic or metal with built-in control elements (two or more).
Functionality and design different models may differ, but all devices perform the main task - the transmission of alternating current through circuits with voltages up to 600 V (at a frequency of 50, 60 Hz), thereby giving signals to change the operating mode of the units.
The devices are also used in electrical networks with direct current up to 400 V, while changing the settings can be done both stationary and remotely. Most often, push-button panels are used to transfer power to magnetic starters, which are an element of the control circuit of electric motors.
The main functions of the devices:
- switching on and off the equipment;
- emergency shutdown in manual mode;
- changing the rotor rotation parameters.
Benefits of using button posts:
- the ability to control the unit without leaving the workplace;
- there is no need to endanger life by penetrating close to equipment connected to high voltage;
- you can choose any set of buttons, which optimizes the control process;
- reliable functioning;
- compact housings made of durable material;
- application safety, high degree protection;
- long operating period.
Design features and principle of operation
The structural part depends on the type of model, but in any case it is practical and reliable in use. On one edge of the switching device there are power contacts that switch the operating modes (on / off) or stop completely in case of an emergency. In the opposite part, an electromagnetic coil is mounted, which provides the process of closing / opening contacts.
The device of the consoles includes the main elements:
- control panel buttons (“start-forward”, “start-back”, “stop”);
- coils of magnetic starters (KM1, KM2);
- contacts of magnetic starters (KM1.1 ... KM2.3).
The principle of operation of push-button posts is as follows. When you press “start-forward”, the coil of the first magnetic starter (KM1) is energized, as a result of which the group of open contacts closes, supplying current to the motor windings.
"Start-back" disconnects the contacts, blocking the connection of the magnetic starter coil (KM2). When the stop button is pressed, the power supply to KM1 and KM2 is stopped, thereby de-energizing the electric motor. The "start-reverse" pusher acts similarly to the "stop" button, but only in relation to the second magnetic starter (KM2).
When you press “start-forward”, the coil of the first magnetic starter (KM1) is energized, as a result of which the group of open contacts closes, supplying current to the motor windings
Post types
There are many different push-button panels on the market of electrical equipment, with which you can control equipment and machines. It is worth noting that the differences between many of them can be traced mainly in the case design and brand, and the functionality and design of many are completely identical.
Therefore, only the main ones that have reasonable technical differences stand out from the manufactured devices:
- PKE, with the help of which the control of metal and woodworking units for industrial and domestic purposes is carried out;
- PKU intended only for industrial equipment, where there is no risk of explosion;
- PKT used for units with a lifting and cargo mechanism.
Main characteristics and operating conditions
Despite the fact that the technical characteristics of the models are identical, there are still differences in the parameters:
- at alternating current the lowest operating voltage is 36 V, at constant - from 24 V;
- rated voltage with alternating current is up to 660V, with direct current - up to 440V;
- rated voltage applied to the insulating layers within 600-660 V;
- four types of nominal operation mode (continuous, intermittent-continuous, short-term, intermittent);
- rated current is 10A;
- for 1 second, a through current with a nominal value of 200A flows through the pushbutton post.
The posts operate in various areas, which are located no higher than 4300 m above sea level
Rules for the operation of control devices
Many models are not designed to work in an explosive environment, so you should familiarize yourself with the technical specifications before purchasing. The working temperature in the room or shop should be within the range of -35 - +40°С.
The posts operate in various areas, which are located no higher than 4300 m above sea level.
To ensure long-term operation of devices, it is necessary to monitor the humidity of the environment.(50% is considered acceptable). An increased level of moisture affects the condition of the contacts, disables them. In addition, it is important to monitor the degree of dust and gas contamination of the room. A large amount of dust and gases can cause fire or smoke.
During the operation of the post, do not allow sunlight to hit the body, this will lead to overheating of the device.
Post Models
(Schneider Electric) is a pendant model with a polypropylene body. The device is designed to control a single-speed motor of lifting equipment. There are 2 buttons and one emergency stop on the case. Mechanical wear resistance is 1000000 cycles, but at proper maintenance And correct operation The device may last longer. The cost of the remote control is 4815 rubles.
(Schneider Electric) is a suspended structure with a polypropylene body. The device is designed to be connected to a two-speed motor of a lifting machine. The model is equipped with 4 buttons and one emergency stop. The rated operating power is 65W, which corresponds to a wear resistance of 1,000,000 cycles. The cost of the post is 8014 rubles.
(IEK) has built-in 2 buttons (non-latching). The degree of protection of the model is IP54, the rated voltage is up to 400 V at alternating current. The body is made of plastic. The cost is 430 rubles.
(Russia) has a plastic case with two control buttons (non-latching) and one emergency shutdown. Rated voltage - 440V / 660 V. The degree of protection corresponds to IP40. The cost of the device is 162 rubles.
(Schneider Electric) has a suspended structure, the body is made of polypropylene. The device is equipped with 6 buttons and one emergency stop. Mechanical wear resistance is at least 1,000,000 cycles. Rated voltage - 600 V. The cost of the model - 7155 rubles.
- The correct operation of the posts is associated with a competent selection of the device. All technical characteristics must correspond to the parameters of the equipment to which the connection is made.
- The body of the push-button device is made of non-flammable materials, but this does not mean that the device can be placed during operation with heat sources or under sunlight. Additional heat entering the contacts will cause them to overheat.
- Posts of Russian production, which are related to explosion-proof fittings, are supplemented with letter designations: "V", "PVK" or "KPVT".
- In modern models, a button that performs the function of a pusher plays a special role. It is designed in two versions: with position fixation and self-return. When choosing, it is worth considering the features of the technological process to optimize control.
- It is better to purchase posts in specialized stores or from an official representative. This ensures warranty service and reduces the risk of system failure during operation. A conscientious manufacturer values its reputation, therefore, before going on sale, products undergo quality testing.
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