AC contactor power operation

It is the principle of electromagnetic consisting of a multi-way switch. Internal coil is energized, the electromagnetic force and the normally open main contacts normally open auxiliary contact is closed, the main circuit and auxiliary control circuit is switched on. After loss of power in the coil, relying spring return, normally open contacts open.AC contactor breaking widely used as power and control circuits. It uses the main contact to open and close the circuit, with auxiliary contacts to execute control commands. Main contacts  mcb circuit breaker open three, four set of contacts, and often two pairs of auxiliary contacts with normally open and normally closed contacts function, small contacts are often used as intermediate relay with the main circuit is used.AC contactor contacts, the silver tungsten alloy with good electrical conductivity and high temperature ablative. AC contactor AC solenoid power comes from the action, the electromagnet consists of two "mountain" shape the young quartet built silicon, one fixed, put coils in the above, the operating voltage has a variety to choose from. To make magnetic stability, the core of the pull side, coupled with short-circuit loop. AC contactor in the loss of power, relying on spring return. The other half is the active core, structure and the fixed core to drive the main contacts and auxiliary contacts open short. More than 20 amps interrupter contacts plus a hood, disconnect the circuit using the electromagnetic force generated, quickly pull off the arc, to protect the contacts. AC contactor production as a whole, appearance and performance is improving, but the function remains unchanged. Whether and to what extent the development of technology, electri cenergy meterr still has its importance. 1, the contactor has many series and parallel electrical devices are single-phase load, and therefore, the multi-pole contactor used in parallel in several pole. Such as resistance furnaces, welding transformers. When used together with a few Voltage stabilizer, you can use a smaller capacity contactors. It must be noted, in parallel contactor Conventional thermal current is not exactly proportional to the number of poles in parallel. This is due to a positive dynamic and static contact loop resistance values ​​are not necessarily exactly equal, to cause a positive current is not flowing evenly. Therefore, two parallel current after analysis can be increased only 1.8 times, three-pole parallel, the current can be increased only 2 to 2.4 times. In addition, the need to point out, because in parallel to each pole contacts can not simultaneously turned on and off, therefore, can not improve the making and breaking capacity. Sometimes the contactor can be connected in series with several pole, the increase in the fracture as the contact arc can be split into a plurality of segments, the ability to improve the arc, the arc extinguished speed. So after a few pole series can improve its operating voltage, but can not exceed the rated insulation voltage contactors. After a series of contacts Conventional thermal current and rated current does not change.