Two-pole machine - breaker, while the chain terminator neutral and phase. Designed for circuits 220 and a number of other cases. The term is sometimes encountered in the theory of relays, gaming machines, devices for binary notation circuits with only input and output, performing a certain logic function.
Without Google patents store we would have lost the wonderful pictures and interesting information about the two-pole machines. We can not ignore A.C. Walker ([email protected]) for the remarkable facts collected by this man on the electricity transmission lines and their protection.
Two-pole machine is often presented as a two-pole circuit breakers. The difference in the blocking unapproved work. Both the machine switched on and off simultaneously. The requirements are provided by the SAE. Wishes to send to the topic of electrical machines. These two links are able to provide information on the structure and give a moderate idea of the historical development of the issue.
It is prohibited to use instead of a two-pole, two-pole machine, mechanically bridge linking the handle. Historically bipolar circuit breakers started to be used for DC circuits that are guaranteed not to get hit by the electrochemical power source with equivalent electrodes.
The general concept
Initially, circuit breakers are used to protect the equipment and for the voltage regulation. This calls for lightning effect of compensation, other natural factors (including birds). Completing the picture voltage spikes caused by switching, on and off the equipment (high-power users). It is pertinent to recall that the volume of production of energy at the beginning of the XX century looked ridiculous. For example, Russia's first floating power plant gave out 35 kW of power. Any heater can overload or underload it when changing the operating mode. To block unwanted effects used circuit breakers (circuit-breakers).
About the role of machines rarely mentioned in foreign literature and silent in the domestic. Several headings below are typical sentences, which are trying to justify the use of the two-pole machines. automatic protection idea occurred to the engineers after the development of the first accident. Not all industrial tooling worked perfectly, with a photo of the building protective equipment after the explosion of the oil machine is given an example of the text.
A typical example of a single-pole machine of the late XIX century, see the patent US693416 A, issued February 18, 1902. This electromagnetic switch, when a sharp rise in current in the coil pulls the armature with the contacts, interrupting the power. Already in ancient times knew of the dangers of arc, for its suppression applied forked blade-type contact. When retracting the anchor straightens mechanical transmission of the two shoulders and snap spring. Return to work is done manually by the operator. The principle of operation is based on the accumulation of magnetic energy coil, because tension lines disappear gradually, a period of time just enough to trip the circuit breaker.
Regulatory functions bipolar automaton see for example patent US725799 A, where a number of electromagnetic switches will adapt the voltage of the dynamo. High-voltage circuit breaker for protection against short-circuit currents of today look like in the patent US844353 A Frank Hartmann in 1907.
True inventors bipolar automaton (US797048 A) claimed that their product is a single compound mechanical switches. These should actuated single solenoid mechanism or manually. Harry Davis and Arthur Reinders either did not want to reveal the secret, or had no idea why you need a two-pole machine. Justification looks like this: unit usefully applied to reduce the labor of the operator and the moving parts of the equipment as a whole.
The authors believe that a two-pole machine is convenient to disable the three-wire circuit, common at the time (Europe, Russia, the United States). In Germany, the current supplied by three wires. Two-pole machines can be a long, two-phase power supply system existed until the end of the first half of the XX century. The number of lines managed to gradually reduce the increasing voltage.
An additional industry machines find application bipolar puskozaschitnoy device asynchronous motors. The single-phase network (now 230), starting and running windings are activated simultaneously, as the shaft acceleration is output from the first steps to reduce reactive power output. In patent US1665223 A manual sample represented a similar device. Frank Roller writes that the operator is able to simultaneously close both the pole, after the acceleration of the shaft - turn off the start winding. On April 1928 it was considered important to the invention.
Subtotal: bipolar machines advantageously used in industry as protective, regulatory or processing device. For home appliances such refinements guard work biphasic devices found in the home (preferably ovens and cookers).
need to apply
Professional electricians differently explain the need for a two-pole machines. The reasons boil down to two words:
The authors believe that the reasons are not the only and not the first in the list. The main purpose of a bipolar automatic gap becomes two conductors when necessary. For example, when the lines are the electrical potential, or in areas with high risk of: bathroom, kitchen. Personal reasons cited by the authors as an argument for using a two-pole machine:
- In the homes of old buildings all the wires are white, so there is no slightest opportunity to understand where is the phase. Devices do not distinguish which side that apply: fork symmetrical. Consequently, it is possible to mix the neutral and phase. We need a two-pole machine, guaranteed to be disconnected. According to the rules, only to tear the neutral can not for obvious reasons: the favorable conditions for the electric shock when handling devices unexpectedly for the person.
Answer. The above argument is not entirely true. Electricians do not have the right to arbitrarily change the shield wire, according to the standards (SAE, etc.) Can not be in the holder of the lighting device start phase and in the outlet of the established norms of the phase of the left. Master in danger of losing their jobs or become responsible for the accidental death.
- Argument. "Master" is able to accidentally mix up the wires. Therefore, we need a two-pole machine (see. previous paragraph):
Answer. Any electrician to do the work required to make the test. Professional knows that the cartridge can not be fed phase and in phase outlet is on the left. To check the master has a screwdriver indicator to help detect an error. Finally, the owner is able to independently verify whether not brought to a single-pole automatic neutral. This is done simply by opening the flap. In older homes can be turned out bulb, check the cartridge is held.
- Argument. Master got stubborn and does not believe that the phase of the left outlet. Therefore, we need a two-pole machine ...
- Answer. In older homes sockets and lighting plant with a single wire. Therefore, by changing the phase of the location, the electrician zavedet it on the cartridge. Refer to the EMP, the authorities and the court. In new houses show the machine where the poor guy started a neutral. PUE can not be neutral to tear without first deactivating both phase.
- Answer №2. Try to trust in the humanity of the master. If, indeed, there is no difference which side is the phase in the house no traffic jams and machine, to say that for the screening of device housings on the side of petal wound neutral. Protect the vanishing equipment. Change the location of the phase, he started a master on the body 220 (in line filters of computers does not light up orange light in the latter case). To understand that by microwave radiation and powerful computer if zeroing circuit to remove completely.
- Argument. Neutral able be energized due to an overlap with the column wiring fall. We need a two-pole machine ...
- Answer. In the above case, a bipolar machine will be a good defense. In the village, in the country where wooden poles, it is permissible to fork out and pay a little more. As for the metro, it is easy to imagine what awaits in the case of such a skew owners of three-phase equipment: big money, huge losses, and someone will pay for it. energy supplier that knows not want to pay, and protection against such accidents.
- Answer №2. In the event of collision provider could conclude with industrialists agreement to install the latest automatic control phase imbalance, avoiding loss. Then double-pole automatic protection will not save, because the device is used exclusively for repair. Do not save and differential machines, people will grasp with both hands and body due to contact voltage electric shock. Protection is able to not work.
- Output. If you are afraid of a neutral, protection against potential drift apart. Is achieved, for example, using the system TN-C-S by combining the zero conductor to local earth circuit. At neutral resistive divider formed, the risk is lower, the lower the resistance of the earthing resistance and current drip into the soil.
In older homes the SAE rules are not systematically carried out. And error argument can not be considered seriously. It is recommended to check all the bullets under the bulbs, sockets, etc. for correct electrical connections. This will eliminate the direct danger of electric shock, improve the electromagnetic environment in the house. Any wire considered to be the source of radiation, even if just under phase. The ceiling is dotted with such garlands, lights in the radio like a Christmas tree. This is easily seen with the help of a screwdriver contactless indicator.
Finally, in a house with imported equipment recommended TN-S system. Approval familiar to people versed in electronics and who saw the system input filters western equipment. In this case, its own ground circuit for each phase of the network. Otherwise it is easy to break the rules of safe operation of three-phase networks with neutral gluhozazemlonnoy. Enough to have in the apartment two feed lines of three, that in most cases and there. Summarizing - a two-pole machine will not become a form of protection against potential drift in neutral. This is a specialized unit for the operation of equipment connected cleanly and correctly, without errors.
Finally differential machine will not save in the event of a skid. He picks up the earth leakage minuyuschuyu neutral. If you fall under the contact voltage is not formed by the grounding, work will not leakage protection, and limit the maximum current. Then there is no difference in the number of poles in the machine. The implication of the need neutral ground to enter the building. What has been done in most Soviet-built homes where the problem is so urgent.
Foreign networks TN-S is safer. They can not use three-phase equipment (need additional measures), but the user does not suffer from an ordinary household appliances. Those who wish to safely advise properly equip TN-S system and the territory to put the differential machines. A further embodiment is considered neutral protection installation on a flat input isolation transformer a grounding circuit at the local one of the points of the secondary winding (not to be confused with the protection WC GOST P 50571.11). This is guaranteed to provide a neutral conductor. Further protection is carried out according to the regulations.
History: The emergence of the need for the application of the two-pole machines
Initially adopted standards for electricity Nikola Tesla: the amplitude of the voltage of 110 V. It is now practiced in the United States. Before Tesla was Edison who swept Nikola around your finger twice on the total amount up to 75 thousand. dollars. At the time of 1885 one ounce was worth $ 20.67. Nikola Tesla has managed to walk in 3628.5 ounces of gold, which is in the area quintal (103 kg). The authors suggest that in the current war Edison lost a lot more, and most importantly - forced to think about the real weight of the business of speech in the United States.
So Nikola Tesla insisted on the introduction of the AC because of the obvious benefits and the desire to annoy Edison. Last understand what threatens the reorganization of production, went to the cunning, to avoid "weasely" European core in personal business. Both sides pulled the blanket over himself, it is easy to guess, this is due to bipolar machines. And a direct link: many lines - a lot of poles.
According to historians, in 1873 he passed the Gramm electricity by as much as three-quarters of a mile on the Vienna exhibition. The first held outside of England and France, it was intended to give strength to the people after the defeat to Prussia and Italy wars. Gram had already invented known dynamo with a ring unit and displayed in operation. Current is pulsed, single direction. The exhibition scientist noted that his invention, according to the principle of reversibility, capable of operating as an electric DC motor. Of course, exhibited the design stood for more than two windings, otherwise this would have happened.
Interpretation of the things to pass a constant current over long distances is not easy. Current lost in the copper wires. Therefore, it was necessary to take a large cross section, making the stock to "shrinkage". Four years after the Vienna exhibition Edison company creates and starts promoting devices for lighting. Along the designs of electric power meters, etc., working with constant current. Nikola Tesla appears... to create the first workable model in Europe, the young inventor deceived officials by 25 thousand. dollars and on the advice of a friend goes to Edison himself. Apparently, to experience American hospitality.
Here, the inventor finally inflated and promytarivshis couple of years doing odd jobs, Nicola finds a sponsor and a partner opened their own firm. To him strive for masteries Westinghouse, associates together are beginning to fight for alternating current. Case quickly go to the mountain, Edison tries to keep the position. But to no avail. Along the way, the famous Menlo Park (NJ) invents horror, torturing animals and invented the electric chair, trying to prove the danger of alternating current. Tesla meets intelligent methods ...
Transmission voltage wire
Registered record (1882) for electricity transmission. According to available data the merchant and organizer of exhibitions Oskar von Miller in Munich wanted to arrange in order to attract the audience something commensurate with the demonstrations in Paris. For this purpose hired Frenchman (obeying fashion for foreigners) Marcel Deprez to the power transmission arranged to Miesbach. From the distance came out 35 miles (about 70 km). For three days - a world record.
The demonstration took place remarkably successful. The steam engine and a half horse power dudel and generates (at dynamo) voltage 2 kV. Easily calculate the current, if the 1 hp = 0.74 (0.74) kW. By Ohm's law for subcircuit find: 1110/2000 = 0,55 A. By today's standards, the number of funny, amusing, that three quarters of the energy lost on the road. To the consumer reached the current and the voltage dropped to 500 V. We want to show - the transfer of energy at a distance is possible only when a large voltage. For a simple reason: the loss of an active resistance is due to the current shock. To do this, we raise the potential of up to 2 kV, although Edison's network are designed for 110 V.
Let's go back to Nikola Tesla. At the end of the 80s the scientist did the trick and began to pursue the debtor - a claim that was just kidding. It's no joke - 200 horsepower transferred in 1891 at a distance of 175 km with an efficiency of 75% - with an alternating current into three phases. Line 15 kV joined the exhibition in Frankfurt from Lauffen am Neckar. Easy to see that at the said distance DC transmission efficiency Despres amounted to 10% or less. DC current can not be used with such great effort without converters.
The scientific community, it became clear that by increasing the voltage, can achieve a good result. In 1912, the limit was 110 kV, he has risen to 220 in 1923. What remains close to the current state of affairs. Powerful line remains LEP Ekibastuz-Kokshetau with the Voltage 1.2 MW (1982). As a result, the current transfer efficiency over long distances is quite large. Above 2 CF rise no sense because arises between the ground line and corona discharge. For today's typical transmission line loss of 2.5%. In the US, where the voltage is lower, lose 7.2%.
Tesla figured out in advance the possibility of more based on reason rather than on the hand. On this occasion, the scientist went a dispute with Edison, who argued that it is better to taste 100 options than will sit and wrestle. Tesla would be able to convey and direct current, but for the sake of principle did not undertake such efforts. Edison considered it the only solution to use two wires and a neutral (this is not the end, there were a system of four or five wires for DC). This reduces the losses on the line and the parallel wiring betrayed minimal resistance. Therefore, increased transmission distance, when the comparative safety.
This happened in 1883, a year after the introduction into the everyday life of John Hopkinson three-wire system from England... just as Tesla assembled the first engine and showed European entrepreneurs. Which indirectly suggests anticipation Edison in relation to future events. Too many coincidences for a mere accident. Tesla won his war.
Finally, came the idea of the two-pole machines: they need to break off at the same time the two lines does not matter - AC or DC. Most of the powers traditionally use such a system. For example, the recommendation of the IRTS 1891 recommended the introduction of a DC three-wire line at 225 V (if The authors correctly understand the source, indicated by Wikipedia, explain in detail the signal interface nobody bothered). It is a mistake to think that the three-wire line is considered sophistication. Known European sockets invented in pre-war Germany's 30s and kept two lines energized at 110 each + ground petals. Like there was in other states. Do not say that the two-pole machine would remain without work.
It is interesting! Edison made it a rule to transmit the voltage at 10% greater than required to consumers. The stock lost in the wires. Policy Edison de facto become de rigueur for all energy suppliers. Today figures formed in a similar manner: 110, 220, 660, 6.6 kW, and so forth.