Characteristics of circuit breakers

I apologize, but is it possible to explain the concept of rated current? If, for example, we take a single-phase circuit breaker at 16 A, then it should, in theory, operate at any current above 16 A. How then can we understand that a circuit breaker of category C has a minimum trip current of the electromagnetic release of a circuit breaker of characteristic C of five times the rated current "?

Valentine, rated current of a circuit breaker is the current set by the manufacturer, which the circuit breaker is capable of conducting continuously at the specified ambient temperature (GOST R 50345-99 Small-sized electrical equipment. Circuit breakers to protect against overcurrents of household and similar purposes).

If the rated current of the circuit breaker is exceeded for a long time, the thermal release trips (but it may not be). The greater the current, the faster it works. The response time can be determined by the protective characteristic of the machine. The electromagnetic release trips instantly at high currents (short circuit currents).

Machine Category (B, C, D, etc.) is determined by the cutoff ratio, i.e. the ratio of the short-circuit current passing through the machine with respect to the rated current of the machine. For category C circuit breakers, the cutoff ratio is five. Those. a circuit breaker with a rated current of 16 A and a cutoff ratio of 5, will instantly trip only at a current of 80 A or more. At lower currents, the thermal release must trip.

But what about the characteristics of G and L? I often meet them, but there is almost no information about them on the network, so I found L: 2.5 - 8, and G: 8 - 12 denominations, from another source G: 8.7 denominations, help me figure it out, it is very necessary. Thanks in advance.

If you do not believe it, then the absence of machine guns with the x-th “B” in Russia is felt.

Alexander.

There is a question. I have installed on the chain of sockets diff. automatic machine ABB 30 mA, C16.

I plugged in the sockets:

Heater - 2500 W

Fan heater - 1500 W

Hair Dryer - 2000 W

Total - 6000 W

Current - 27, 27 Amperes

This is more than 1.5 times the nominal value of the machine.

All this was turned on for about 10 minutes. The machine was not turned off.

Somewhere I think wrong (I understand the curve), or is my diff "not very"?

Unfortunately in our country diff. ABB machines are mostly fakes. And it can be checked mainly in the electric laboratory with special devices, loaders. Be careful and careful.

Vyacheslav, 10 minutes for a one and a half time excess may be short, would exceed once every 5 would be knocked out right away. And here it takes time to heat the conductors.

zxc, the time for heating is not conductors, but the thermal release of the difavtomat (or circuit breaker).
Vyacheslavif not mistaken, the thermal release of the circuit breaker trips 1.5 times the rated current in less than an hour. In this case, it can be 15, 30 minutes, maybe 50 minutes.Moreover, the response time of the thermal release is indicated for an ambient temperature of 30 degrees. If the air temperature is higher, then the thermal release of the circuit breaker will trip earlier, respectively. And vice versa: the lower the ambient temperature, the longer the circuit breaker will hold the current. That is, in a cold room, the machine can hold a current that exceeds the nominal one by 1.5 times more than an hour.

In addition, when calculating the load of household appliances that you have included in the network, take into account the actual voltage value of the household network. As a rule, the voltage of a household network is rarely within the nominal value. If the voltage is 220 V, then the load of electrical appliances, as you calculated, is 27.27 A. And if, for example, the voltage is 260 V in the network (which is not excluded), then the total load of the electrical appliances listed by you is 23 A.

And I want to add about the rated power of household appliances, which is indicated in their passport (on the case). It is almost always slightly different from the actual power consumption of these electrical appliances. Moreover, the actual power can be either less or more than indicated. If you are interested, measure the load current of the electrical appliances listed by you and the actual voltage in the household network. You will make sure that the load current of a particular appliance does not correspond to the current, which is calculated based on the specified rated power of the appliance.

In addition, in most electric heaters installed regulators, thermostats. Perhaps, for the specified period of time, the heaters did not work at full capacity.

Is there a breakdown voltage in the characteristics, i.e. what maximum voltage can be applied to an open circuit breaker without breakdown? It is clear that there is a worker, but it is necessary to know the punch.

In this case, the dielectric between the contacts is air. It is necessary to know its temperature, humidity, dustiness of the medium and the distance all this characterizes the dielectric characteristic of the dielectric - see table dielectric properties of air (section electrical engineering - dielectric materials).
If the machine worked at high currents, there is soot, then it can block in the future. In 6000 installations, it is impossible to approach less than 0.6 m to live parts.
If you put the machine under kilovolts, you can lead a polemic here).

Please tell me, are there any similar machines in the performance for radio electronics?

Vyacheslav,Vyacheslav, if you had an automatic machine with characteristic “A”, then this explains everything, because under such conditions the thermal release should work after 20-30 minutes. when exceeding the rated current of the machine more than 1.5 times, while e. the magnetic release of the machine will trip if it exceeds the nom. current as much as 2 times in about 5 ms.

* And if, for example, the network voltage is 260 V (which is not excluded), then the total load of the electrical appliances you listed is 23 A. * - in my opinion, the resistance is constant, not the power. Therefore, the current at 260 V will be 32.23 A.

Yes, not in your opinion, but according to the law of electrical engineering. But the current will be slightly less, since the hair dryer and fan heater, in addition to the active one, also have reactance.

Is it "diff. Automatic machine ABB 30 mA, C16." should disconnect on overload?

In my opinion, it only protects against leakage - "differential currents".

Finally, at least one thinking person was found. Diff protection or RCD is designed to protect against leakage currents, and if this is not a combined device which includes electromagnetic and thermal trip units, then during overload it will not work a priori. But as it is painted, it’s a pleasure to watch.And after all, everyone considers themselves specialists. God forbid such specialists in the energy sector.

A reactive power hairdryer is generally nonsense. See do not fly away on such a jet hairdryer.

"if it is not a combined device"

A differential automaton is an RCD + AB. Umnyak.

The diff machine is 2 in 1 and RCD (triggered by a leak) and AB (triggered by an overload and short circuit)

Kind.
Tell me, there is an introductory 3-phase IEK 16A machine in the apartment, with a short circuit it knocks it out and in the entrance to the apartment (there is no access there), the neighbors say that there is also IEK 50A
What should I change them so that the apartment will always work earlier in such cases?

Alexander, when overloaded, the machine with the lower rated current will work faster. As for the short circuit, in this case, both the apartment and the machine that is installed in the entrance can work. Perhaps in this case, you should pay attention to the characteristics of circuit breakers. The article tells about the classes of automatic machines - B, C, D. For example, if you install a circuit breaker with class C in the entrance, and an input into the apartment of class B, then for the same rated current the protective device with the lower frequency of the trip current will be the first to operate electromagnetic release, that is, a room machine with characteristic B. Only in your case it is not clear why there is a 16 A circuit breaker at the entrance to the apartment panel and 50 A at the entrance. Or is it a general machine that feeds several accounting records?

no, the builders set this up until I changed anything yet, yesterday I was convinced that it costs 50A as standard, but Schneiderovsky (maybe they changed it already and it was actually also 16A, so 3 automatic machines worked - for the group, entrance and entrance)
I read about multiples, but everyone in the apartment has standard C, although with a lower rated current, I'm afraid input B will work earlier.
I decided that I would put in the apartment a differential automatic machine of the input such a DPN N VIGI 4P 6KA 40A C 300MA. A to immediately kill 2 birds with one stone
in the entrance - it’s in the dashboard on the floor after the counter, and the apartment is separately opening with the breakdown further into groups.

Tell me, if you put in the main switchboard: Rated current, A63. Rated breaking capacity, kA (AC) (IEC / EN 60898). Will it be possible for the consumer to supply a 63A, 6kA automatic machine, or will this be a mistake?

I installed a machine on 32A, once there was a short circuit, but the machine did not work. After that, I began to manually turn off the machine before any exit from the house. They say this can’t be done because the machine will fly. I ask you, Alexander, to answer who is right in this case?

Explain what the characteristic expressed as a kA means in the designation AB, for example: Automatic switch 1p 16A SH201L 4.5kA 2CDS241001R0164 ABB. What do these 4.5kA mean?

Dmitriy, Dmitry, this characteristic (4.5 kA) indicates the maximum permissible load on the machine itself. That is, not the one when it turns off, but the one when it definitely does not turn off and, or even burns out))

That is, it is 4.5 kilo Amps, that is 4500A. That is, with a current of up to 4500 everything will be fine with him. With a larger current, no one guarantees anything. Automata with a high value (6kA) are more expensive, as they are able to "hold" large currents. In general, this is another defense and characterization of the machines themselves.

Differential circuit breakers - “difavtomats” - combine the functions of a circuit breaker and a differential load switch (RCD), functions: short circuit protection, protection against voltage overloads, protecting people from electric shock when touched directly, the sensitivity of a difavomat 30mA.A differential circuit breaker is installed instead of a conventional single-pole circuit breaker, and is able to protect one specific circuit.

Valentine,
If the modular circuit breaker did not work during a short circuit, it means it needs to be replaced, the market is full of poor-quality products, I can only recommend what I use myself: EATON, PL-4 (4kA) and PL6 (6kA) series; Hager, Schneider Electric series "EASY9", "Acti9"

MaksimovM,
And if, for example, the network voltage is 260 V (which is not excluded), then the total load of the electrical appliances you listed is 23 A.

Dear, teach the law of om and do not mislead such ignoramuses into ignorance.

GregI know Ohm's law. But where does he come from? I meant that if the load of electrical appliances is 6 kW, then at a voltage of 220 V the load current from these electrical appliances will be 27.27 A, and if the voltage rises, let's say up to 260 V (which is possible), the current will be 23 A (we divide 6000 W by 260 V - we receive a current).

The devices then remain the same, only the voltage in the household power supply changes.

Are you not familiar with the fact that with increasing voltage the load current decreases at the same power? For the same purpose, they increase the voltage in electric networks in order to transmit the same power through wires, but at lower currents.

Valentine, firstly, you need to replace this machine with a new one, since the fact that the machine does not work during short circuit indicates its obvious malfunction. You are not correctly told that the machine will “fly” - it has already “flown” because it does not fulfill its functions.

Secondly, for greater reliability, it is necessary to install another circuit breaker at the input of home electrical wiring. Thus, one of the machines in the event of a short circuit must disconnect, while the second will act as a backup. For example, one circuit breaker is located in the metering and distribution panel, and another machine is in the home panel. There should always be a redundant protective device.

Rostislav,
Dif Put on the input and RCD as close as possible to a dangerous consumer specialist pancake

urids300, difavtomat is a residual current circuit breaker and circuit breaker in one unit. You can put an RCD and an automaton on the input, or you can use a difavtomat. The same thing on the outgoing lines - you can put two separate protective devices, or you can use one combined, that is, difavtomat. The difference is only in the nominal parameters. On the outgoing line, we select a 16 A difavtomat and a 10 mA differential current - this is the same as putting separately a 10 mA RCD and a 16 A circuit breaker.

Who produces types MA, A, K, Z? are there catalog numbers or manufacturer markings?

MaksimovM Do you even know why they write 225-235V 100W on incandescent lamps? Or on a heater 230V -2000W? You have already been told: Learn the law of om! The load is purely active, so the current increases in proportion to the voltage! And the inscription 2000W means that such a power will be consumed by the fan heater from the network at a voltage of 230V NETWORK. About inductive load. Yes, there is a fan with a power of up to 20 watts - you can neglect it. I say again: teach, and do not mislead people.

Greg, "MaksimovM,

And if, for example, the network voltage is 260 V (which is not excluded), then the total load of the electrical appliances you listed is 23 A."

If you increase the voltage of the network, do you think the resistance of the kettle or vacuum cleaner will change to a smaller side in order to save the watts you calculated ?? Have you ever gone to school before talking about the laws? Or maybe power is constant, not consumer resistance ...))

Konstantin, MA special protection category. It is applied, for example, in SHU-DU smoke removal cabinets.
Protective characteristic of type MA (12 - 14 In, with tolerances reduced to +/- 10%), long-term permissible current, higher than the current of the thermal release of the machine or steady-state short-circuit current is greater than the current of the magnetic trip of the machine, if it has only current protection (characteristic MA). As a rule, for such systems, the increased breaking capacity of the machine from 25kA is selected. Examples:
409885 Auto off DX3 3P MA 63A
409884 Auto off 3P MA 40A
409883 Auto off DX3 3P MA 25A
4
Along with the MA, there can be machines with a D-curve along the curve - the current in the circuit is 10-14 times higher than the rated current (i.e., the 16A circuit breaker will disconnect the circuit at a current of 160-224A).
Replacement with the same curve code 10-14 In shutdown time, but not always maximum off. ability:
2CDS283001R0631 S203P D63 15kA
2CDS283001R0401 S203P D40 15kA
2CDS283001R0251 S203P D25 25kA
2CDS283001R0201 S203P D20 25kA

It is also possible to replace the MA by the correspondence of the curve with K automata of the Schneider characteristic:
Replacement with a similar curve code 10-14.4 In but not evenly distributed off. ability:
A9F95363 iC60L 15kA 3P 63A K 10-14.4 In
A9F95340 iC60L 20kA 3P 40A K 10-14.4 In
A9F95325 iC60L 25kA 3P 25A K 10-14.4 In

Well, you need to remember that in smoke removal systems, the presence of thermal relays and thermal protection in machines is not welcome. Operation only on short circuit. In general, the machine should work in an IP65 cabinet and while everything around it burns with a blue flame, and smoke removal works.

He assembled a shield for himself, put all the B-machine guns in. He walked around 10 stores, nowhere in stock. Half looked like a fool, half agreed that the time was right, it suits the house more, but they don’t take it, so they don’t carry it. As a result, I took it on order. I won’t say anything about selectivity - so far only difs have been practiced. But in old houses, in my practice, I often beat out the introductory there, where the junk machines (ekf, tdm, etc.) well or worth c25 to the outlet and c32 introductory.