What is the phase in the electric current

The phase can often be heard in a conversation about electricity. But, of course, the word has a much broader meaning. What is the phase, its cycles, how is it connected to grounding. We learn about this and many other things in the next article.

What is the phase

In physics, a phase is understood as one of the states of a substance (for example, water is in the liquid, liquid crystal, crystalline and gaseous aggregate state). In addition, it refers to the stage in the oscillation cycle (for example, in the wave motion).

In astronomy, the word has a slightly different meaning. What is the phase in this science can be understood from observations from the Earth behind the celestial body (for example, the Moon). That is, it can be designated as the visible part of the illuminated hemisphere of the celestial object from the Earth.

In the theory of economics, it is widely known what phases of a cycle are. This is when in a certain period of time (cycle) there is a regular activity.

Consider what this term implies in electricity.

Phase in electricity

Do you know where electricity comes from in power plants? Everywhere the principle of its occurrence is the same: the rotation of the magnet inside the coil leads to the appearance of an alternating current in it . This effect is called EMF, or electromotive force of induction. A rotating magnet is called a rotor, and coils attached around it are a stator.

The alternating voltage is obtained from a constant voltage, when the latter is bent over the sine, as a result of which a positive or negative value is reached.

So, the magnet comes into motion, for example, thanks to the flow of water. When the rotor rotates, the magnetic flux changes all the time. Therefore, an alternating voltage is created. With three installed coils, each of them has a separate electrical circuit, and inside it appears the same variable value, where the voltage phase is shifted around the circle by one hundred and twenty degrees, that is, one-third relative to the one that is located next to it.

Or maybe feed at home as before?

This scheme was called three-phase. But you can safely power the house and with the help of one such coil. In this case, the first end of the coil is simply grounded, and the second - leads to the house, where this wire is connected, for example, to the fork of the kettle. At the same time, the second prong pin is grounded. The same electricity will be obtained.

Propagation of three-phase current

The three-phase current enters the houses through power lines (where the voltage reaches thirty-five kilovolts). It is believed that it is the most economical and on all sides more profitable compared to conventional current.

In industry, the power is supplied by a three-phase current, since a rotating structure on it is easier to build, and in general it is more mobile and has more power.

Wires

We will understand what phase, earth and zero wire are, in more detail.

It is easy to imagine a three-phase generator with a "star" connection. The phase connection point is called neutral.

Usually, it is grounded to increase safety, since if the device fails, then in the absence of grounding, there will be a danger to the person. When you touch the device, it will simply be shocked. But in the presence of grounding, there will be a leakage of excess current and no risk is generated.

So, all together - zero wire, ground and wire phase are necessary to ensure the safety of people. In new houses under construction such a system is envisaged, while in old houses it is absent.

Definition of phase

Sometimes it is necessary to determine where the phase wire is located. For an ordinary outlet, this, perhaps, is not necessary. But when connecting, for example, chandeliers, the phase should be fed directly to the switch, and zero - directly to the lamps. Then, if the light is turned off, when a lamp is replaced, the person will not be electrocuted. And even when the device is on, if it accidentally touches the lamp, although it will be hot, but the impact will not happen.

There is a very simple and convenient device for determining the phases. In appearance it resembles an ordinary screwdriver. But inside the device has a light bulb, which when touched to the phase will light up. At the same time, the finger should touch the metal patch of the device at this time.

Some brave souls decide to determine by completely unsafe methods. These include the so-called "control", when the wire is placed under a stream of water, touching them with a neon bulb, or brought into contact with the battery.

Needless to say, it is better not to resort to methods that become dangerous not only for the experimenter, but also for others. Especially the indicator screwdriver is currently very inexpensive.

If the electric cables are correctly installed in the rooms, the blue wire will indicate zero, yellow-green will indicate the ground, and the phase will be indicated in black or any other color. But the work of electricians, unfortunately, is not always conscientious and qualified. Therefore, colors may not coincide with the purpose.