Button control stations are devices of a rectangular or square configuration in a housing made of durable plastic, plastic or metal, into which button controllers are mounted. Functionally and constructively, the devices may slightly differ from each other, however, the principle of operation is identical for them - the transportation of alternating current along 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 with direct current up to 400 V (settings can be changed in stationary or remote mode). The main scope of use of the devices in question is industrial industries. The principle of operation of the device is the transfer of power to magnetic starters 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 appliances with electric motors. Most often they are used in control circuits of three-phase motors of synchronous and asynchronous action.
The use of push-button switches enables the operator of the ventilation unit to adjust the operation of the unit from its workplace, without rising into the coverage area of the equipment. As a rule, button control stations are located on a common panel, the so-called general control station.
The main functions of the considered devices:
- Activation and deactivation of electrical appliances and devices.
- Carrying out the reverse (switching the direction of rotation of the rotor).
- Emergency shutdown of machines and other devices.
Operation in the high voltage circuits of the considered regulators is not provided.
Connection
The connection of push-button control stations and their subsequent operation is carried out using coils of magnetic starters, providing direct and reverse switching of the motor. The remote control is controlled by the “Start”, “Stop” (“Forward / Backward”) buttons.
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 windings of the electric motor. When the "Start-back" function is activated, the second magnetic starter coil is turned on, while normally open contacts close parallel to the "Start-forward" mode.
The inclusion of the “Stop” key ensures that the electric motor is de-energized, while the power to both starters is not supplied, the contacts are in the open state. When reverse is activated, the operation of the contacts is similar to starting, only power is supplied to the second magnetic starter.
Features
Depending on the number of controlled consumers of electric energy, push-button control stations can be two- or multi-button. It is worth noting that in the manufacture of installation and electrical works, single buttons are used, which are set 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 mounting the fittings to the place selected as the main operating post. A separate category includes control panels for hoists (FCT), bridge lifts and crane beams with ground control.
The main element of the push-button control station is the push button, which is a switching electrical fittings with manual control. Consider the types of pushers and devices themselves, their differences among themselves, as well as features in the areas of application.
Pusher Types
Pushers used in the design of a 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-resetting options. These buttons are returned to their original position by means of a spring located on the push rod in the lower part.
- Fixed (self-retaining) models. Buttons of this type fix the contact tightly until pressed again.
The most widely used two-button modification, pushers are painted in different colors. In the free position, the "Start" button has open contacts, and the "Stop" closed. Pushers can vary in color and shape:
- The color of the lock button is usually red or yellow.
- Launchers are painted in black, blue, green or white color.
- The shape of the buttons can be in the form of a mushroom, a cylinder, and also be sunk in the case.
Types of remotes
A wide range of button controllers is available on the modern market. Functionally, they are almost identical, differing 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.
Operational characteristics of the device:
- The limit value of the switched voltage (alternating / direct current) is 600/400 volts.
- Switching current - 10 A.
- Maximum response cycles are 5x10 ₆ .
Button control stations for PKU are focused on use in an environment protected from explosions, where the accumulation of a gas-dust mixture does not provoke a violation of the integrity and performance of the controller. The parameters of this electrical fittings are similar to the characteristics of PKE.
PCT
This type of button-type control stations is designed for aggregation of lifting devices such as electric hoists, bridge cranes and beam cranes equipped with manual ground control with electrical equipment. As a rule, this type of controller is operated in various production facilities, in warehouses, in special production facilities.
The characteristics of the operational and electrical plan are commensurate with the similar parameters of the PKU and PKE versions. Chinese-made electrical fittings under the IEK mark are also sold on the domestic market. Its indicators are completely identical to their 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 control circuits of equipment that is operated in explosive atmospheres (mines, oil storages, paint shops and similar industries).
Widespread use posts type XAC-A (Germany) and KS (Poland). Also in this segment, remote push-button electrical fittings are more often used.
In conclusion
PVC is a push-button control station that is used to control electrical equipment in an explosive atmosphere. Analogs without the “B” index are used in safer areas. The principle of operation of all controllers with pushers is identical; they differ externally in the number of buttons. Models in a metal case are stronger and cost a little more. When choosing a post, you should take into account the features of its further operation and the compliance of the characteristics with the conditions of use.