AC power contactors
Power contactors are specific electrical mechanical switches that are used to switch current on and off under normal operating conditions as well as when overloads occur. They are used in a variety of conditions, although they are not used in a domestic environment. However, they are indispensable in industrial environments.
AC power contactors: characteristics
Power contactors belong to a group of components such as mechanical switch with a single resting contact connection, which is used to transmit signals in strong current networks. They are somewhat similar to relays, although the construction of contactors is more complex. The central element in all contactors such as AC power contactors is the coil along with a large electromagnet. Many other accessories can also be fitted to modern contactors, which are responsible for switching power on and off. These will be, for example, signaling devices, various interlocks, as well as protective elements. If one wishes to automate the operation of AC power contactors, one may opt to set up an automatic time control for the contactor. The selection of power contactors itself requires knowledge of the characteristics of each type. It is also necessary to know the specifics of the equipment to be activated by the contactor. For this purpose, it is worth using a special calculator. Well, the numerical value of the motor power expressed in kW should be multiplied by 2, and also choose the first contactor from the series, which is numerically higher than the obtained result. Power contactors are precise and the fact that they come from such reputable manufacturers as Eaton, Moeller and Schneider guarantees that they will be durable, reliable and safe in use.
When it comes to motor current networks then AC power contactors prove to be indispensable. They activate the power system, while allowing to mechanize the processes of switching on and off selected devices, which extends their life. Thanks to this, the risk of a possible failure is also minimized. AC power contactors are used to control motors and modular devices, which are used to switch on and off: pumps, heaters, lamps, fans and sirens.
Contactors of this type as embedded protection systems are mounted on a rail, which allows for precise and fast installation of these elements in power devices. Simply connect each contactor to the circuit, connect the control, and connect the support wire and the device trip wire to the appropriate phase.
AC power contactors: selection
When selecting a power contactor from the AC group, the function and the specific performance range of the circuit should be taken into account. Therefore, the type of current and voltage should be taken into account. To select the right contactor for a particular motor, the rated current in amperes drawn by the machine should be taken into account and a contactor of not lesser rated current should be selected. In heavy industrial use, oversizing may also be used. If a contactor is selected that is 1 or 2 sizes larger, the life of the contactors that are frequently energized will be extended.
Very often, power contactors are confused with auxiliary contacts. However, the difference is that contactors connect power circuits, while auxiliary contacts are responsible for devices which transmit low-current or zero potential signals. AC contactors are used to switch electrical devices such as motors. The signal is passed on through the connector. The signal is either voltage or current depending on how the device is constructed. It is always advisable to check all the parameters carefully to be able to match the particular type of contactor to the device it will operate. In view of this, it is advisable to know the exact features of specific devices. Then the AC power contactors will be selected correctly. AC power contactors should be used in accordance with the recommendations indicated by the manufacturers.
