What is Contactor? A contactor is an electrically managed switch applied for switching an electrical influence circuit. A course typically commands a contactor with a greatly lower power degree than the switched circuit, such as a 24-volt coil electromagnet testing a 230-volt motor switch. Unlike common design relays, contactors are designed to be directly connected to high-current load devices. Relays are often of the lower range and generally reserved for normally closed and normally open purposes. Devices switching more than 15 amperes or circuits considered more than a few kilowatts usually are called contactors. Apart from optional backup low-current connections, contactors are about completely fitted with usually open form A links. Unlike relays, contactors are originated with comments to control and contain the arc generated when interrupting heavy motor currents. Contactors come in several forms with varying proportions and features. Unlike a course breaker, a contactor is not intended to prevent a short circuit flow. They range from those holding a breaking current of various amperes to thousands of amperes and 24 V DC to various kilo volts. The substantial size of contactors varies from a device small quite to pick up with one hand to large machines almost a meter yard on aside. Features of contactor:
- Lighting control
Contactors are usually used to present basic control of extensive lighting connections, such as an office structure or retail building. To minimize power distribution in the contactor coils, securing contactors is used, with two operation coils. One ring, immediately moving, closes the power course connections, which are then automatically held joined; the second coil opens the links.
- Magnetic starter
An irresistible starter is a device designed to confer power to electric appliances. It includes a contactor as an essential element, while also proffering power-cutting, under-voltage, and overloading resistance.
- Vacuum contactor
Vacuum contactors suitable vacuum jar encapsulated connections to contain the arc. This arc damage allows the accessories to be much lighter and use less space than air break connections at more robust currents. As the connections are encapsulated, vacuum contactors are applied widely in dirty applications, such as drilling. Vacuum contactors are also widely used at common assessments from 1000-5000 volts, effectively dismissing oil-filled circuit breakers. Vacuum contactors are just suitable for use in AC systems. The AC arc formed upon the connections' availability will self-extinguish at the zero-crossing of the prevailing waveform. The vacuum prevents a re-strike of the angle beyond the open links. Vacuum contactors are, therefore, very effective at disrupting the energy of an electric arc. They are used when almost fast switching is required, as the periodicity of the AC waveform determines the highest break time.
- Mercury relay
A mercury relay, seldom summoned a mercury displacement relay or mercury contactor, is a relay that practices the fluid metal mercury in an isolated sealed container as the switching component.
- Mercury-wetted relay
A mercury-wetted relay is a kind of relay, generally a stalk relay, in which the contacts are sprinkled with mercury. These are not supposed contractors because they are not designed for courses above 15 amps. Components of Contactor: There are components of the contactor. The connections are the current-carrying part of the contactor. This incorporates power links, different scents, and contact origins. The electromagnet (or "coil") presents the driving power to close the contacts. The enclosure is a structure covering the attachments and the electromagnet. Sections are made of insulating elements such as Bakelite and thermosetting plastics to protect and insulate the contacts and provide some protection against personnel touching the contacts. Open-frame contactors may have an elaborate enclosure to protect against dust, oil, report hazards, and weather. These are especially useful in DC power circuits. AC arcs have periods of low current, during which the angle can be extinguished with relative ease, but DC arcs have continuous high current, so blowing them out requires the angle to be stretched distant than an AC arc of the same draft. The irresistible holes in the pictured Albright contactor (produced for DC currents) further than doubled the recommended the contactor can break, extending it from 600 A to 1,500 A. Types of Contactor Devices: Knife Blade Switch The knife-edge switch has used the opening in the late 1800s. It was the first-ever contactor applied to manage electrical devices. The switch consisted of an element strip, which would drop onto a connection. This switch had a lever for pushing the button down or stirring it up. After then, one had to wreck the knife-edge switch into the ended status by attaining next to it. However, there was a problem with this method of switching. This process caused the contacts to wear out quickly since it was difficult to manually open and close the switch fast enough to avoid arcing. Consequently, the soft copper switches encountered corrosion, making them exposed to dampness and dirt. Over the years, the motors' size increased, which further generated the need for larger currents to operate them. This created a potential physical danger to manage such high current carrying switches, leading to a severe safety concern. Manual Controller Since the knife blade switch became possibly dangerous to use, engineers came up with different contactor device, which allowed several missing characteristics in the knife blade switch. This device was committed to as a manual controller. These features included: Safe to work The non-exposed unit, which is appropriately encased Smaller size Single break contacts replaced with double break contacts As their name suggests, double break contacts can open the circuit in two places concurrently. Thus, even in a smaller space, it allows you to work with more current. Double break connections divide the attachment in such a way that it creates two sets of contacts. Magnetic Contactor The magnetic contactor does not need human interruption and works electro-mechanically. This is one of the most excellent designs of a contactor, which can be used remotely. Thus, it helps reduce the risks involved in running it manually and putting working personnel in possible danger. Only a small number of control current is needed by the magnetic contactor to open or close the line. This is the most popular kind of contactor used in industrial control applications. Top Manufacturing Companies:
- The connectivity
- Panasonic industrial devices
Leading Manufacturing countries:
Market overview: According to Verified Market Research, the Global DC Contactor Market was accounted at USD 315.17 Million in 2018 and is projected to reach USD 879.20 Million by 2026, growing at a CAGR of 13.98% from 2019 to 2026. Although related to a relay but with higher popular ratings, a DC contactor is an electrically managed switch used for switching an electrical power circuit. It is managed by a course that has a much more low power level than the switch circuit. Unlike general-purpose relays, the DC contactors are produced to be directly connected to high-current load devices. Name: Samira H. Revised Date: 16-09-2020