Электромагнитный пускатель представляет собой kind of contactors. It is used to convert substantial loads. The main application is activation, switching off and reversing of asynchronous three-phase power units.
The most significant parameter of the electromagneticstarter - is the weight and dimensions. The product has a rather high performance in this section, since the maintenance of ultimate loads requires an appropriate design.
These products use powerful contactsystems with arc extinguishing compartments, which also affect the increase in size. Despite this, devices can have the same operating current, but differ in weight and size. Contactors are made in the clear. In this connection, devices should be installed in lockable cabinets or compartments protected from ingress of dirt, foreign matter and dirt.
Thanks to simplicity and ease of maintenanceelectromagnetic starter (220 volts) is widely used to control various industrial and household components (machines, furnaces, ventilation systems, etc.). Scope of application is almost unlimited, ranging from escalators and elevators to serious production systems.
The considered device will allow to protect the machineor installation from an erroneous launch. The units block the power supply if a block is expected to interrupt or overheat. In addition, the electromagnetic starter protects against abnormal overloads that can damage the entire system.
By types, electromagnetic actuators differ in the following parameters:
According to the type of connection, the PML electromagnetic starter is divided into categories: АС-1, АС-3 and АС-4. Between themselves, they differ in voltage and type of connection.
For example, AC-1 - inductive or inactiveload, АС-3 is a direct start with a squirrel cage rotor, АС-4 is a similar system with the possibility of braking and switching off by means of a reverse current supply.
Starters electromagnetic 220 V, depending on the equipment and additional options, are divided into three main groups:
Electromagnetic starter connectioncarried out by means of signal contacts, providing the moment of "sticking". For example, after a short press of the “Start” key, the ends of the starter are closed. If the specified button is held briefly, the contacts are disconnected and remain in the neutral position until it is turned on again after the power supply is restored.
If the starter is electromagnetic on 380 Vrun in reverse mode, it uses taps to block the second analog, This prevents the possibility of a short circuit. A huge number of branches is useful for assembling sophisticated control systems, if necessary. These may be analogs with software adjustment, the possibility of surcharges or load reduction, as well as schemes with remote access. There is also a predisposition for the introduction of the number of contactors with additional blocks or runners with hooks.
Thermal relay for the considered devicesserves to protect against possible prolonged overload or violation of the integrity of the insulating layer. A special plate is provided in the working circuit, which opens the circuit at critical current parameters. The level of "conflict" is regulated within 15%. It follows from this that overloading should be taken into account initially when developing a design project.
The following is not recommended:
В работе рассматриваемых устройств имеются some nuances. They are associated with the use of starters. The operation is performed by applying a counter-current with an intense increase in the load on the main contacts. As a result, it is desirable to initially lay in the parameters of the stock about 1.5-2 times.
In this segment, it does not hurt to mention analogs with a permanent magnet. They are focused on long-term operation without interruption, connected via a rectifier device.
Electromagnetic MaintenanceThe PM-12 starter, like its analogs, is practically not required until the working life of the device is exhausted. This is due to the fact that the functional range directly depends on the opening / closing cycles. They may be several hundred thousand times, if it concerns the standard fixtures used in dry and ventilated areas.
In the process, you must followcondition of the locking elements. They must be constantly tightened, not pass moisture and dust, made of appropriate materials. Cleaning contacts is very rare, without unnecessary need, this procedure is better to exclude from the service. This manipulation is shown in the case of a strong reflow, burning. Processing of parts is carried out by means of a file with a fine-grained surface.
After prolonged use, consideredInstruments may produce increased and uncharacteristic sounds. If this moment is transformed into a regular rattle, you should disassemble the unit, detect and correct the cause of the problem. In addition, it will not be superfluous to check the coil and core. Before assembly, it is recommended to clean the work items with a clean cloth, and also to check the assembly for deformations and cracks.
Wear resistance non-reversibleelectromagnetic starter is determined by checking the mechanical stability of the working contacts. In almost any electromagnetic relay, the manufacturer specifies two types of warranty. The second parameter relates to electrical wear resistance, which is opposed to a working burning arc.
Switching capabilities of the devicedetermine the possibility of switching on and the maximum current parameter, which allows not to violate the technical characteristics for wear resistance indicated in the instruction. For example, triggering per minute from 8 to 10 times indicates a malfunction of the system.
Synchronization deactivation fuse sayssmooth operation of contacts and electrical wear resistance. If there is a fading reaction at a certain point, this signals the possibility of forming an arc, which welds the working group of devices, making them unusable. The specified parameter refers to the defining moments that affect all the main characteristics of the electromagnetic starter.
Power consumption can be redistributed byswitching and operation of the main relay. Features of thermal protection make it possible to preserve the integrity of the motor windings, preventing equipment failure.
In case of improper use of the consideredthe device, the difference of damage in case of improper start can reach 30-40 percent (if there is an incorrect activation of the equipment). Particularly affected by this moment is the vibration and bouncing of parts during the shutdown of the damped indicators at a certain amplitude. The higher the weight of the rolling element, the lower the pressing force.
Как правило, образовавшаяся дуга при отключении power plant goes out. The moment of transition is usually fixed at zero. At a frequency of 50 Hz, this situation can occur no more than 100 times per second. As a result, the update procedure does not particularly affect the protective functionality of the unit. Silver contacts have optimal characteristics.
Выше были рассмотрены характеристики и features of electromagnetic starters. As can be seen from the review, devices can work with voltages of 380 and 220 volts, as well as commute useful energy. It is recommended to choose the considered devices on the basis of the final parameters and the assigned tasks. There are modifications on the market that satisfy users' requests for activating a separate power unit or automating an entire production hall.
