Electric contactors are switches that function in a way that is similar to relays. They have numerous applications in different industries. For instance, contactors are frequently used to give focal control of large lighting establishments, especially in office and retail buildings. They are applied in such a way because they don’t consume a lot of power. Thus, to lessen power utilization in the contactor coils, latching contactors with two working coils are used. This means that one coil, quickly energizes, shuts the force circuit contacts, which are then precisely held shut; the subsequent curl opens the contacts. Battery contactors are also used in magnetic starters. This is a gadget intended to give the capacity to electric engines. It incorporates a contactor as a fundamental segment, while additionally giving force cutoff, under-voltage, and over-load assurance.
Components of a contactor
A contactor is made up of the following parts:
a. Contacts- the contacts are the current-conveying some portion of the contactor. The contacts are made up of the power contacts, assistant contacts, and contact springs.
b. The electromagnet- this part is the main driving force that is located to close the contacts.
c. The enclosure- this is the part in which the electromagnet and the contact is hosted. This part is usually made of protecting materials like Bakelite, Nylon 6, and thermosetting plastics to ensure and protect the contacts and to give some proportion of security against the workforce contacting the contacts. Open-outline contactors may have a further enclosure to ensure against dust, oil, blast risks, and climate.
d. Magnetic blowouts- these parts use magnetic coils to extend and move the circular electric segment. These especially come in handy in DC circuits. Air conditioning curves have times of low current, during which the bend can be quenched without any difficulty. However, DC circular segments have nonstop high current, so blowing them out requires the bend to be extended farther than an AC circular segment or arc of a similar current.
e. Economizer circuit – in some cases, an economizer circuit is likewise introduced to decrease the amount of power that is required to keep a contactor shut. An assistant contact lessens the coil current after the contactor closes. Normally, more power is used to close the contactor than that which keeps it closed initially. Such a circuit can spare a generous measure of power and permit the curl that is energized to remain cooler. Economizer circuits are almost consistently applied on direct-current contactor coils as well as on large exchanging current contactor coils.
A conventional contactor will have a coil input. The coil input might be driven by either an AC or DC depending on the construction of the contactor. Universal coils that are driven by AC just as DC are likewise accessible in the market today. The coils can be energized at a similar voltage as the engine the contactor is controlling. It can also be independently controlled with a lower coil voltage more qualified to control by programmable controllers and lower-voltage pilot gadgets. Certain contactors have a series of loops that are connected to the engine circuit.