What is the difference between a contactor and a starter?

Live and learn)))

I never thought that they could be so different ...

this article even made me dig deeper into the internet, where, in principle, my like-minded people were found))).

I always thought that the CONTACTOR is an electromagnetic device with several contact groups))

A MAGNETIC STARTER is a composite device designed to control and protect the engine, consisting of one or more CONTACTORS, protection against short-circuit and overload, control elements and alarms (buttons, keys, bulbs), and all this in one case.

And there is also an opinion on the Internet that the differences m.u. there is no contactor and starter at all, just a MAGNETIC STARTER is the Russian name and Contactor came to us from behind a hill)))

There are no electromagnetic starters abroad, and all devices are called contactors. In our country, the contactor and the starter are different devices.

GOST R 50030.4.1-2002:

"Contactor (mechanical): A mechanical switching device with a single resting position, not operated manually, capable of turning on, conducting and disconnecting currents under normal circuit conditions, including during operational overloads.

Electromagnetic contactor: A contactor in which the force required to close the closing main contacts or to open the opening main contacts is created by an electromagnet.

Starter: A combination of all the switching devices needed to start and stop the motor, with overload protection. "

Initially, only contactors were used to switch electrical circuits. DC contactors were used at the end XIX century. Then, relatively simple complete devices were needed to control and protect asynchronous motors with a short-circuited rotor and came up with a device such as a starter.

The first starters in the USSR were made on the basis of contactors. There were such P series starters (in fact, it was a contactor without a shell with two single-phase thermal relays located on its base). From that moment on, the contactor and the starter became different apparatuses. Over the next years, both starters and contactors were produced and improved. When switching currents up to 100 A, starters were usually used, and at currents of more than 100 A and with increased requirements for reliability in operation, contactors were used. Classic contactor - KT6000, KT7000. Does he look like a starter?

It is wrong when imported starters are called contactors, since according to the definition, by their purpose and configuration they are electromagnetic starters.

The significant difference is that the starter is designed for frequent electronic switching.
circuits up to 100A, and the contactor for infrequent switching is stronger than 100A. With frequent starts, the heavy contactor mechanics will quickly crumble.

I don’t agree about the limited number of switching contactors compared to starters. Switching wear resistance of the contactor KT6000 - 3600 times per hour. This is once per second. It is written on the contactor itself. Any magnetic starter when switching rated currents with such a frequency of on and off will fail much faster than the contactor.

Vaderius,
PML starter, commutes much more than 100 amperes)))

“It’s not right when imported starters are called contactors, because according to the definition, they are electromagnetic starters by their purpose and configuration.”

And what's wrong with that? You yourself cited the definition of a starter as a device with all protection devices. In the bare form, without attached relays, RCDs and other things (which are sold separately and for some money), any imported contactor has no protection. A purely switching device that deserves the name of a contactor is 100% matching your definition.

In general, any import contactor does not fit this article in any way. They start somewhere with 5-10A, have a case, can be assembled in a variety of combinations and weighed with all sorts of ryushechkami and then on the list. At the same time, in terms of design, the number of contacts and the possibility of weighing all sorts of gadgets, the contactor for 6A and 400A does not fundamentally differ (apart from the natural differences associated with the dimensions and current magnitude, of course) ... In terms of resource, yes, it is higher for small ones. But this is not because the purpose is different, but due to completely natural physical reasons. Larger current requires large dimensions and mass. And no one pulls every five seconds a contactor for hundreds of amperes. What hangs on such a line will die faster than the contactor itself from such treatment. And the declared resource of these contactors is measured in thousands of starts per hour and millions in service life.

I was taught in vocational schools in 1968-1970 that the starter differs from the contactor only in the presence of thermal protection. We even had this question on the exam. It is more difficult to distinguish a powerful relay (up to 100 amperes on airplanes) from a low-power contactor (10 amperes in household automation).

The trouble with our people is that they are trying to explain something that they themselves do not understand))

"Contactor (mechanical): A mechanical switching device with a single resting position, not operated manually, capable of turning on, conducting and disconnecting currents under normal circuit conditions, including during operational overloads.

Electromagnetic contactor: A contactor in which the force required to close the closing main contacts or to open the opening main contacts is created by an electromagnet.

Starter: A combination of all the switching devices needed to start and stop the motor, with overload protection. "

I can’t understand what could be incomprehensible here. If there is only a switching device, then this is a contactor. And it doesn’t matter if he has at least one pair of power contacts. Will he have a protective case or not. He is heavy or not heavy. The KT series is a contactor, the KMI series is a contactor, the PML series is also a CONTACTOR (see GOST text). But if any such contactor has at least a thermal relay - this is already a starter.

Kovvx, Well, of course. Despite GOST 50030.4.1-2002, the definition of the starter and contactor remains in the field of personal experience for everyone. The letter P in the same PML and PME is precisely the "starter", although this is a "separate switching device." And CT are contactors. Everyone will call them contactors, even if they collect reverse for starting the engine.

Actuator-start electric motor or other load.
Contactor-large switch with nth number contactcomrade

In the manuals in English they write the contactor (contactor or starter), it is a contactor.
You can call the usual button a starter.
What is the difference between a resistor and resistance or a switch from a switch, a bag from an automatic machine.
A pointless argument.

I agree with Ilya that the starter differs from the contactor only in the presence of thermal protection.

Yes, in my opinion the last two thoughts are still the most sensible! - (In my opinion.)

Not only the article itself is interesting, but also the comments on it.

The article is interesting, but GOST, etc. normative documents often resemble the works of room specialists.

Starters are usually up to 380 V, contactors up to 1000 V.

I think it’s incorrect for me to intervene in this discussion. Since I use any of these gadgets arbitrarily, but with the calculation of the load and the corresponding "installation" (parallelization of contacts to increase conductivity). I am grateful to the author for the publication.
Personally, I am currently interested in all possible information on working with LED lighting lamps (circuits, the principle of operation of components, repair).

Hello, smarter colleagues. I don’t want to “boggle” with my knowledge of the nomenclature theory of differences between starters and contactors (I personally don’t care). But yesterday I launched the heating system electric heating circuit invented by me (it is dual-mode 5 and 5 + 5 (kW). In which I used 63A starter
The contactor 63A was written on the price tag in the store. You will not believe! I did not even argue .... (I'm not a theorist). The system is working. The house is warm. Good. (The practice in the real cases done is much more interesting (disputes are essentially about nothing in the cold room in front of the monitor (this is me about myself, in the sense that if I also connected to the “establishment of the truth”, I would not have time to build the circuit and the heating system would not work until the debate ended.) By the way, I came up with a circuit to disconnect the 220V home network when the voltage rises to 380V (in the event of a neutral contact in the drive room (there was already a case with a sad outcome for refrigerators and computers) ). The power part of this protective The device is a 40A circuit breaker, which is turned off by a lever soldered to the armature of a small relay, which, in turn, is triggered by the supply voltage passing through the diode bridge, into the diagonal of which the KC650A zener diode is connected (Ust = 150V). this relay turn on the LED indicator "! 380 V". (In practice, I checked it works clearly. Sincerely, Evgeny Kirichenko.

Very helpful article.
Itself would not be able to describe in such detail.

I explain for those who are near: the difference between the starter and the contactor is that the starter has a pair of contacts that are held by a saturated coil, the coil is saturated by short-term switching of these contacts, and contactors do not have a pair of contacts to hold the coil.

I explain for the distant: on the starter you can put a button on the contactor can not.

Alexander, you're not right. Look at the photo of the contactor from the article. On the right is a set of block contacts. They are used for including for holding the coil in the on state, i.e. in this regard, the contactor and the starter are no different.

andy78,
I will not argue, because the name speaks for itself, and is designed in factories for specific needs.
According to you, that the relay, that the contactor, that the starter is the same thing, then assemble the starting circuit on REC 78/4, or on KM25-40.

No, not the same thing. Relays are needed for switching in control circuits, reproduction and amplification of signals. Starters - for switching loads, up to about 100 A, although there are starters for high currents. Contactors - for switching high currents (over 100 A) in circuits with a large number of on / off switches and where increased reliability is needed (cranes, elevators, etc.).

Dear colleagues, I’ll be brief, the difference is only in the design feature (I don’t know why the contactors of the MK series call it the contactor ?, possibly the presence of electromagnetic arc extinction). This feature makes the contacts of the contactor self-cleaning!

The argument is clearly taxonomic. "Taxonomy (from other Greek: system, order and - law) - the doctrine of the principles and practice of classification and systematization" From the foregoing it follows: the starter and contactor differ only in the design of the contacts - the contactor has arcing chambers.

Structurally, the contactor resembles a magnetic starter, however, due to the robust and reliable mechanical design, contactors allow frequent on and off operations (about 1200 starts per hour), while starters do not have this ability, because starters in comparison with contactors have a relatively weak contact system. By the number of main contacts, contactors have one, two, three, four, and five-pole designs. There are contactors without extinction and with extinction of the arc. According to the type of current of the main contacts, they are also divided into contactors of direct and alternating current. Contactors are available for currents up to 2500 A. There are no starters for such high currents.

And what do you advise to apply for the assembly of an automatic transfer switch for a private house from a gas generator, according to a budget option? Thanks..

Sergey wrote everything correctly above, contactors differ from starters by the presence of arcing chambers. For example, using this link you can view in detail various photos on contactors KT-6023. Copper contacts are installed under the asbestos-cement arcing chambers.

It can be concluded - Vieste contactors with stray type heat can carry out the function of a starter, and the starter cannot actually replace the contactor

The main difference between the contactor and the starter is that it has, in addition to each pair of main contacts, an additional pair of contacts made of heat-resistant material (cermet, etc.). When the contactor is turned on, the closure of additional contacts occurs earlier than the main ones, and when disconnected later. Thus, all spark, arc, switching effects, account for additional contacts. Mostly contactors start at 100 Amps.

The difference is that the starter breaks each circuit at two points, and the contactor at one!

I don’t know, at our nuclear power plant, PML-2100 starters for controlling valves, have recently begun to be called according to documents - PML-2100 contactors.

A magnetic starter differs fundamentally from a contactor only in that it has a thermal relay in its design that trips the starter at an unacceptably high current. In addition, magnetic starters are usually performed at lower currents than contactors.

Please tell me why the voltage of the contactor is higher than the voltage of the starter?

Right here, someone wrote above that the argument is meaningless. Contactor is an older word, already in the 19th century it was known, the starter is a more modern term. There will be no mistake if you call the starter a contactor (on the contrary, I’m not sure). Someone here wrote that supposedly contactors are not designed for frequent switching. This is complete nonsense: in electric trains with RCSUs, pneumatic direct current contactors (linear contactors) are used just for switching power circuits of traction motors.They turn on and off several times a minute. Especially on subway trains where the lines are short and engine connections are very common. And by the way, such contactors are controlled by a voltage of 70 V DC: this voltage is supplied to the valve (solenoid), which opens the valve through which compressed air is supplied to the cylinder of the linear contactor. In general, old contactors are monstrous devices :)