Phases in electrical engineering: definition of the concept, neutral wire and grounding, alternating electric current

Phases are stages, periods, special states of something. The definition, borrowed from the ancient Greek language, has become widespread in various spheres of life that are not directly related to each other. For example, the phases of the moon and sleep are known. It also took root in physics, economics, sociology, and electrical engineering.

Areas of use of the concept

A phase is called not only a certain state in physics. This concept is widely used. And if you look closely at the phenomena in the description of which it is used, you can find a lot in common in them. In some cases, the wave effect can be recognized as such.

The definition is used, in particular, in the following areas:

1. Physics. The phase here is a stage in any cycle of oscillation (including just in the movement of waves). And also - the state of matter, which can change depending on external conditions.
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2. Astronomy. The degree of visibility of celestial bodies from the Earth. Also - finding them in relation to other objects (this is also used in astrology).
3. Economy. The cycle of time when the system reacts in a certain way with activity (passivity) to changes in conditions or passes points of decline or growth.
4. Sociology. Almost like in economics, only the studied area of ​​this science is the reaction of society, the tendencies of its development.

And yet the most famous phase in electrical engineering. It is in this area that most people encounter it. The light in the house is more important than the features of the Moon's passage through the next constellation.

Application of the principle of phasing

Interestingly, the expression "electric phase" is, even as a definition, applied in three cases. First, as a part of the device, which is included in the overall circuitry. Secondly, a live core. In this state, it differs from the second wire, shorted to ground, which is grounded and called zero. Third, the expression refers directly to alternating current.

The system built on the principle of phasing works as follows:

1. The magnet spins in a coil and in this way a current is generated, which is made alternating. A similar system is used in power plants. The movement of its parts is provided by the flow of water or steam.
2. To obtain the desired result, three coils are installed in the device, which are located at an angle relative to each other. The current parameters in them are the same, but each has its own circuit.
3. This three-phase current goes to industrial buildings and residential buildings through power transmission lines.
4. At the input, any object is powered according to the coil principle. One core is immediately grounded, the second is wired to sockets. They also provide grounding.
5. It is made for the safety of objects for people. However reliable the current is, it must be handled with care. Grounding systems reduce the risk of electrical shock.

As for the concept of "phase of the current" in relation to its oscillations, then you need to know that it constantly changes its value from zero to maximum and back. This wave process is continuous. And any point in his time is called a phase.

Secrets of home electrical wiring

At home, people mainly deal with alternating current. A typical circuit has three strands. The working electricity enters the network, and the second returns it back. The third is for grounding.

Even to use a home network, you need to understand some basics:

1. The earth conductor has no load. It acts as a safety device against electric shock. It also removes "excess" electricity.
2. The return vein is called zero. If the system is installed correctly, there is no voltage on this wire either. But in case of errors in the wiring, it cannot be ruled out.
3. The work lead is especially dangerous to handle. With him, even with the network disconnected, you need to be extremely careful.
4. Household appliances (except those that run on batteries) are turned on only when the entire circuit is properly closed. Therefore, it is necessary to determine the required cable for each point during installation.

The networks in modern apartment buildings are now pretty reliable. But even in such conditions, it is easy to answer the question of why to know about the intricacies of working with wiring - this will come in handy both in case of problems with household appliances, and when carrying out major repairs.

Ways to find phase and zero

When working with electrical wiring, installing and connecting electrical appliances, starting with elementary chandeliers, it is important to clearly define the phase and zero. This can be done both with improvised means and with special (even elementary) devices. In this case, precautions should be taken.

You can determine which core is energized and which is neutral as follows:

1. By wire color. Subject to the installation rules, blue or blue should correspond to zero, yellow-green or green to earth, and black, gray, white, brown to phase. But it is impossible to be one hundred percent guided by this alone - in practice, the purpose of the veins may not correspond to the colors.
2. With the help of "control". This is an ordinary light bulb screwed into a socket. One wire should be short-circuited, for example, to the radiator, and the second should touch the core. The lamp will light up on contact with a wire that is energized. It seems simple, but in fact, only an experienced electrician can safely use this method.
3. An indicator screwdriver. The most reliable way, provided that the tool is in good working order. It is filled with a light bulb or LED. If the needle of the device touches the working core, the indicator will give a light signal. You can buy such a device for 50 rubles.

Even in a home network, the voltage is 220 V. Therefore, it is also important not to confuse different types of veins. Even the simplest short circuit can lead to big trouble.

By the way, an indicator you can also determine the health of the circuit itself. If he does not react to any touch of the veins, it is time to contact a specialist. And under normal conditions, this automatic detector will help, for example, connect the phase to the switch, and bring the zero directly to the chandelier lamps.