What to do if there are two phases in the outlet. Reasons for the appearance of two phases in the outlet and methods for their elimination

Among the arsenal of tools of any home master there is always an indicator screwdriver, with which they determine the phase potential in home wiring.

Simple design, simple operation and low cost make it popular.

This indicator works clearly, allows you to see the phase potential, uses the principle of active current flowing through the human body and a built-in neon light bulb.

The rules for its use are described in the article.

Working as an indicator, we are used to the fact that the lamp is lit on the phase contact of the socket, and off on the zero contact. We consider this to be the norm. Moreover, we clearly understand that if the phase wire breaks, there will be no glow and we should look for a malfunction.

The integrity of the zero potential at the outlet is rarely checked, and another technology is required, for example -.

When, in single-phase home wiring, the indicator shows a phase on both contacts of the outlet, then an inexperienced electrician begins to think that there are two of them and raises the question: “Where did the second one come from?”.

In doing so, he errs twice on:

about 90%;
the rest at 10%.

In the first case, we assume that there is nowhere for an extraneous phase to appear inside a single-phase network and a completely different malfunction has arisen. And in the second - nevertheless, we will consider the option of the appearance of an extraneous potential.

A brief digression into the theory

When voltage is applied to a household consumer, an electric current flows through it in a closed circuit. If the circuit is open, for example, by a chandelier switch, then there will be no glow.

In this situation, the phase potential reaches the switch, and zero - to the near contact of the base on each light bulb.

Their wires are briefly called phase and zero. After the switch is turned on, the phase potential reaches the remote contact of the light bulb and a current is formed through the resistance of the filament, which flows through the wires of a closed circuit from the source of the supply transformer substation.

If you check the voltage at the remote contact of the bulb holder with an indicator, then it will indicate the phase with its glow, and there will be no glow on the near one. We conclude that here the potential is zero. Now let's look at another option.

Incorrect connection of the switch to the chandelier

In old apartments, they often made a mistake: they did not break the phase, but zero. In such a situation, the lighting from the switch worked normally, but there was a danger of electrical injury when replacing a light bulb, which was always at phase potential.

If in such a situation you use a capacitive indicator, then it will glow on both contacts of the bulb base and one -.

The reason lies in the fact that the potential of the phase along the broken chain from the apartment shield has reached the disconnected contact of the switch.

And there are no conditions for the passage of current - the circuit is open. In their own language, electricians say - a break or a break in zero.

A similar situation can occur in an electrical outlet. To do this, it is enough to disconnect the zero at the input of their block and have a parallel circuit with a connected resistance, for example, a table lamp.

A similar case can arise in a simplified one, when the power circuits of the socket group and lighting are not separated, and all apartment protections are made by electric plugs or circuit breakers of the PAR series.

If there is a zero break at the input of the socket, located, for example, in the kitchen and the light switch is turned on in the room, a similar situation will repeat when the capacitive voltage indicator will glow in both sockets of the socket, indicating the phase potential.

How to evaluate the voltage in the outlet

The phase potential causes the light bulb of the capacitive indicator to glow, but the zero cannot. In the case we are considering, this property misleads a person.
For a correct assessment of the situation, it is necessary to use a device that indicates not one potential, but their difference. This principle works:

bipolar voltage indicators;
voltmeters.

All modern multimeters have a voltmeter mode - combined electrical appliances of a home master.

If its probes are installed in the contacts of a problem outlet, then it will show 0 volts on it, which means there is no potential difference necessary for the normal operation of electrical appliances.

The voltage value 220 will only be between zero and phase of normal electrical wiring.

We conclude: the voltmeter does not show the voltage between the same phase, because it simply is not there. It is present in a single-phase network only between the wires of the phase and zero potentials.

Possible cases of zero break in a single-phase home network

A fault can occur almost anywhere in the wiring, but most often damage occurs where the electrician has made the wiring of the circuit in:

switchboard of the apartment;
junction box;
socket.

It is also possible to destroy the wire insulation layer and break the neutral core with the creation of a contact on the phase.

The error may occur on:

introductory circuit breaker;
electric meter;
zero bus.

The cause of the breakage may be poor contact with the wire due to:

contamination of working surfaces;
insufficient clamping force of the screw connection;
cuts in the metal core of the wire.

Any of them creates increased resistance in the transition section, leading to excessive heating, soot formation, gradually turning into a break.

In this situation, all electrical appliances in the apartment will lose voltage, but the phase will remain present.

If at least one light switch is turned on or a household appliance is inserted into one of the sockets, then the phase potential will pass to the second contact of all sockets through the neutral bus.

You will have to inspect possible damage sites and fix the problem.

A failure with a lack of voltage will manifest itself in the room for which the junction box with a broken zero works. In all other places, tension will be present.

Inside the old junction boxes, the wires were connected with twists and wrapped with electrical tape. At zero, it was usually necessary to make more connections, and the overall twist turned out to be thicker. From this indirect sign, it is easier to test the circuit to detect zero potential by electrical methods.

A zero break can also occur in the wire connecting the junction boxes. To replace it, it is often necessary to chisel the wall and replace the cable. To reduce labor costs, it is easier to create a new highway by placing it on .

Zero break and short to phase in the socket block

Such a situation can be created during improper work on drilling walls, driving nails, screwing screws without taking into account the laid electrical wiring routes, when the integrity of the core insulation is violated and short circuits and wire breaks occur.

The phase potential will appear on both socket contacts without creating additional shunt chains.

Such a malfunction is eliminated by the complete replacement of the faulty section of the wiring.

For those readers who are interested in videos on this topic, we recommend that you watch the work of Sergei Soshchenko: "Two phases in an outlet."

This is just the case when the second phase potential can penetrate into the home single-phase network and the voltage on all household appliances can jump to a linear value up to 380 volts.

The culprit of such an accident is most often the power supply organization, and all involved consumers suffer from it.
Consider the option of an air connection to a three-phase input to a private house.

These wires are open. have a great length. There are many reasons why a phase break can occur. Their number decreases when connected with an electric cable hidden in the ground, which is more often used to power multi-storey buildings. But the human factor and violation of the rules of operation should not be forgotten ...
A zero break in a three-phase network occurs periodically, it must be taken into account.

Operation of a three-phase network in normal mode

Each apartment with single-phase wiring receives the same phase voltage.

Its value of 220 volts is applied to various resistances of household consumers, which are periodically switched to the power supply in a random manner. In the circuit, only currents flow from the generator end through the phase wires to the load and return through the neutral wire.
The zero current consists of the sum of the three currents of all phases and is usually balanced by them. The voltage in the phases fluctuates within the operating standards.

The operation of a three-phase network with a zero break

Here the balanced system is immediately violated. A break in zero excludes the passage of phase currents through it, and the voltage supplied to consumers undergoes changes.

Consider the example of the contour AB. A linear voltage AB is already applied to apartments A and B. Their resistance is connected to it in series and consists of two components.
Due to the total resistance Ra + Rv, the current Iav flows through the circuit, calculated according to Ohm's law. It is common to both apartments.

The voltage drop in each apartment is no longer the same, but depends on the resistance that electrical appliances connected to work have. If one owner is not at home and turned off all appliances, and the second one intensively uses the washing machine and dishwasher, turned on the washing vacuum cleaner and heater, then the situation is unfavorable: all 380 volts will be with one owner. His household appliances will burn out from overvoltage.

You can reduce the risk of damage to your property from a similar breakdown by including it in an apartment shield. It will timely turn off the power when such an accident occurs. RKN is a part of protections and provides in the automatic mode.

Cases of a neutral wire break are explained in detail by the Master007 owner's video: “Zero burnout”.

Supplement the material of the article with your comments, share it with friends on social networks.

There are two phases in the socket. Why is there two phases in the outlet

In normal situations, when checking the operation of the outlet using a voltage indicator, the phase wire causes the light to glow, and with a neutral wire, the light will not light. However, there is a situation where the socket is not functioning, and the indicator detects two phases in the socket. Not everyone knows what to do in such cases. Usually, this happens in buildings where old or poor-quality wiring is installed with violations of installation rules. What are the reasons for this phenomenon?

Reasons for the appearance of two phases

The most common cause may be the destruction of the internal neutral wire as a result of overheating. In this case, the phase will pass through electrical appliances connected to other outlets and fall on the neutral wire. At the same time, the outlet where two phases appear will become inoperative.

To identify the cause of the malfunction, it is necessary to turn off all electrical appliances and all switches from the sockets. After that, the voltage in the outlet is checked again. If there is no positive result, it is necessary to determine the cause of this condition.

Often, this is just a broken wire after any work has been done. To find the place of damage, it is necessary to completely de-energize the apartment and remove the plaster in the alleged place of the break. The damaged wire is connected and insulated, after which it is checked again.
A possible cause may be, especially the one that is installed in the room where the outlet is located. It is necessary to turn off the power supply, open the box and find non-working wires that can be identified visually. In the absence of such, it is necessary to check the remaining boxes one by one. The detected malfunction must be eliminated, and then check the outlet again.
It often happens that the electrical panel is to blame. Here it is also necessary to inspect the condition of all connections and contacts. If malfunctions are detected, it is necessary to call, since it is life-threatening to work independently under voltage.

Overvoltage in the network is one of the reasons

One of the reasons for the two phases may be an overvoltage in the network, due to an increase or decrease in the voltage value. At the same time, the bulbs are either too dim or too bright. If the neutral wire in a four-core cable is damaged, the current rushes to the smallest load.

Thus, 380 volts are formed on one wire, and on the other, the load is reduced to 40-80 volts. In this case, it is necessary to completely de-energize the apartment, turn off all sockets and switches. After that, you need to call in electrical specialists to carry out repair work and subsequent control measurements.

Sometimes an interesting malfunction occurs in the electrical wiring, which puts an inexperienced electrician or a simple amateur in a difficult situation. Such a malfunction is the occurrence second phase in the outlet, which is there in place of zero, which makes you think a lot.

In fact, the same phase is present on both sockets of the socket, since in a single-phase electrical network, an alternating voltage of 220V is formed by one phase and one neutral conductor, and there cannot be a second phase there. But it is the understanding of this that causes some bewilderment when a phase is found in place of the standard zero.

If there really was a second phase in the outlet, then the voltage between both phases would be 380V and all the included household appliances would have to be carried to the repair shop.

A bit of theory.

Without going into technical details, we can say that a single-phase electrical network is such a method of transmitting electric current, when alternating current flows to the consumer (load) through one wire, and returns from the consumer through another wire.

Let's take, for example, closed an electrical circuit consisting of an alternating voltage source, two wires and an incandescent lamp. From the voltage source to the lamp, the current flows through one wire and, having passed through the filament of the lamp, heating it, the current returns to the voltage source through the other wire. So, the wire through which the current flows to the lamp is called phase or simply phase (L), and the wire through which the current returns from the lamp is called zero or simply zero (N).

If, for example, a phase wire breaks, the circuit opens, the current flow stops and the lamp goes out. In this case, the phase wire section from the voltage source to the break point will be under current or phase voltage(phase). The rest of the phase and neutral wires will be de-energized.

If the neutral wire breaks, the current flow will also stop, but now the phase wire, both lamp leads and part of the neutral wire extending from the lamp base to the break point will be under phase voltage.

You can make sure that there is a phase on both terminals of the lamp and on the neutral wire extending from the lamp with an indicator screwdriver. But if you measure the voltage on the same terminals and wire with a voltmeter, then it will not show anything, since in this part of the circuit there is one and the same phase, which cannot be measured relative to itself.

Output: there is no voltage between the same phase. There is voltage only between the neutral and phase wires.

Advice. To determine the presence of a phase and voltage in the electrical network, it is necessary to use an indicator screwdriver and a voltmeter together. Can be used as a voltmeter.

And now let's move on to practice and consider some situations with zero that can be independently determined and, if possible, eliminated without involving the communal energy service:

1. Zero break in the input shield of a house or apartment;
2. Zero break at the input or inside the junction box;
3. Closure of the zero conductor to the phase conductor in case of mechanical damage to the insulation.

1. Zero break in the input shield of a house or apartment.

In the input panel of a house or apartment, the neutral wire may break at the introductory circuit breaker or on the neutral bus. As a rule, the screw connection is loosened, due to which contact is lost between the wire and the clamp, or, in rare cases, the neutral wire breaks off at the clamp and hangs in the air.

Also, due to poor contact between the clamp and the wire, heating and burning of the wire occurs and, as a result, a large transition resistance is formed between them in the form soot, which gradually turns into a cliff.

In the absence of zero, all electrical appliances in the house will not work. But if at least one household appliance remains plugged into the outlet or the light switch remains on, the phase through power supply radio components household appliances or filament the lamp will pass unhindered to the zero bus, and from the bus to all the neutral wires of the electrical wiring. And as a result, there will be a phase on both sockets of sockets and contacts of switches. This is because all the neutral wires of the electrical wiring are connected together on the zero bus.

To determine such a malfunction, it is enough to disconnect all household appliances from the sockets and turn off all light switches or unscrew the light bulbs. After these steps, the second phase of the sockets and switch contacts will disappear. The malfunction is treated by restoring contacts on the terminals of the introductory machine or on the zero bus.

2. Zero break at the input or inside the junction box.

If the zero conductor breaks in front of the junction box or in the box itself, the problem with zero and the operation of electrical equipment will be exactly in the room of the house or apartment into which this box distributes voltage. At the same time, everything in the neighboring rooms will work as usual.

The figure above shows that in front of the left junction box there was a break in the neutral conductor of the wire, and the phase through the filament of the lamp (load) enters the socket zero.

When searching for such a malfunction, the problematic box is opened and the twist of the common zero is found (it is the thickest in the box). The twist strands are cut off, re-cut and twisted together again.

Advice. If the wire is copper, then it is advisable to solder the twist.

When zero breaks in front of the junction box, as shown in the upper figure, in order to find a break, it is often necessary to open a strobe with this wire in the wall to find the fault.

When searching for such a malfunction, first a twist with a common zero is found in the box and untwisted into separate cores. Then each zero core is called up to sockets and up to the ceiling. A core that does not ring out and will be the incoming wire to the box.

Next, this wire is pulled through and the plaster in the wall is opened to find the place of damage to the wire. However, such a malfunction belongs to the category of difficult ones, because few people undertake to pick a wall - it is easier to lay a new track.

3. Closing of the zero conductor to the phase conductor in case of mechanical damage to the insulation.

A situation may arise when drilling a hole, screwing in a self-tapping screw, or driving a nail into the wall breaks the electrical wiring. In addition to this, damage to the wiring is accompanied by a short circuit, due to which the wire is completely or partially damaged. Such a malfunction is treated by opening the place of damage and restoring the damaged section of the wire.

Sometimes with such a malfunction, you can also observe two phases in the outlet.
At the moment of closing, the phase and neutral conductors are welded together, and therefore the phase freely enters the zero conductor. Moreover, even when the electrical equipment is turned off from the sockets and the lighting switches are turned off, the phase will be present on those sockets and switches that are energized from this wire.

The malfunction is treated by restoring the damaged section of the wiring.

If you still have questions, then in addition to the article, watch the video, which also covers the topic of zero break.

In this article, we examined only the most common malfunctions that occur in a single-phase electrical network when the neutral conductor of the wire is damaged. Now if you have two phases will appear in the socket, You can easily identify and fix such a malfunction.
Good luck!

Electrical wiring is done according to simple principles that are studied at school, but some malfunctions often go beyond the standard ideas about the operation of the electrical network. Two phases in the outlet is a common incident that regularly confuses users with insufficient experience in repairing electrical wiring.

Where and why might the second phase appear

Here we must immediately make a reservation that since only one phase wire enters the apartment, the concept of “second phase” implies that the voltage indicator shows the phase in the contacts on which it should be initially and at zero. The second phase, in the correct understanding of these words, cannot be in an apartment.

The next point that you need to know to understand the essence of the problem is that every electrical appliance is a conductor of electricity. The simplest example is a light bulb - its filament glows due to the fact that it is a conductor of electric current. In fact, the light bulb shines because it closes the phase and zero between itself, and a short circuit does not occur because the incandescent filament has a certain electrical resistance. Other devices work in the same way - they are often connected to the network through transformers, the winding of which is made of copper wire. Short circuit again does not occur, because due to the length of the wire and its cross section it has electrical resistance, but in fact, when the plug of any device is inserted into the outlet, the phase and zero are closed in it.

Now it should be clear why there are two phases in the outlet - this malfunction can only appear if there is no zero. The phase comes to the outlet, passes through the electrical appliance included in it and appears on the neutral wire, and from it on those outlets that are located after the zero break. Accordingly, if you turn off all the switches and remove all the plugs from the sockets, the indicator will show the phase on only one contact.

As a result, a phase instead of zero can appear in one single outlet (provided that it is double or triple and a plug of an electrical appliance is inserted into one of the plugs). Further, 2 phases can be in one of the rooms, in half of the apartment, or in general everywhere.

Also, the probability of a short circuit cannot be discounted, for example, when drilling a wall or poor-quality laying of wires in a junction box. With some luck, you can hook the wiring in such a way that the neutral wire burns out from the main network and sticks to the phase one. In this case, the indicator will show two phases in the outlet even when electrical appliances are disconnected from the network.

In this video you can see how this malfunction is reproduced on a specially assembled stand:

Two phases in one socket

Such a case practically does not occur - this is a rare exception that proves the rule. If, nevertheless, this happened - all other sockets work flawlessly, there is light everywhere, and in one single socket the indicator shows two phases, then the socket itself is disassembled first of all. The breakdown is likely to be elsewhere, but first, just in case, you need to make sure that it is not in the place that is easiest to get to.

If you're lucky, then a broken, burnt or jumped-out wire can be found in the socket.

When the socket is working and there are no signs of overheating of the wires, then the next step is to determine how it is connected - directly to the junction box or through another socket. In the second case, there is a possibility that the neutral wire was poorly screwed into the "parent" outlet, and now it has fallen out.

Next, the junction box is checked - this is the most likely place where poor contact can be found. Here it is necessary to take into account that the phase wire is not so demanding on the quality of the twist - if the connection is poor, it heats up, but it still works for some time. The neutral wire can oxidize without visible consequences - in order to see this, you will have to unwind the twists, strip the wires again and assemble everything back.

If the twist is in order, then all that remains is to ring the wire with a tester - if it shows a break inside the wall, then you will have to break the strobe for repairs.

When the outlet stops working in a house where the wiring is done recently and in accordance with all the rules, then it is additionally worth checking if it is a power outlet, to which a water heater or similar powerful device is connected. In this case, the reasons must be sought in the main switchboard, from where it can be powered, bypassing the junction boxes.

Two phases in multiple outlets

The situation is similar to the previous one, but now in several outlets at once, often located in the same room. At the same time, lighting can either work or be absent - depending on the way it is connected.

It makes no sense to check the sockets here, with one exception - if they are all connected by a so-called loop. In this case, wires come from the junction box to one of them, and the rest are connected in series. The PUE strongly does not recommend doing this, but everything can be.

The procedure for troubleshooting depends on the desire to climb to the junction box and on whether there is a possibility of a daisy chain connection. Most likely, a wire break will be found in the junction box, but if all the connections are normal there, then you need to disassemble all the sockets in the room one by one.

Two phases in half of the rooms

This happens if the junction boxes are connected in series one after the other. What to do in this case - the solution is standard - you need to sequentially sort through all the boxes in search of a bad contact.

The whole difficulty is that often there is no connection diagram, so it is not known from which room and to which of them the wiring is laid. You should also take into account the option that the contact can burn both in the room in which the sockets do not work, and in the previous one according to the scheme, where the indicator shows normal voltage in the sockets.

There is a solution so as not to disassemble the terminal boxes in all rooms - you can change the phase and zero on the input shield, and then use a voltage indicator that can show the phase through the wall. Before this, you need to make sure that there is no grounding anywhere in the sockets and, just in case, disconnect the ground, if one is connected.

Two phases in all sockets

If the lights go out in the whole house, and the voltage indicator shows two phases in the sockets, the problem is most likely on the input panel.

In this case, it is also necessary to check the ground wires in case they are grounded. At the same time, until you are sure that there is no voltage on them, you should not touch the ground contacts with your bare hands and prohibit children from touching sockets and electrical appliances.

In old houses, plugs or circuit breakers are often installed not only on the phase, as recommended by the latest editions of the PUE, but also on the neutral wire. The burnout of such a plug is equivalent to a zero break, so it is recommended to check them first.

It is also necessary to take into account the possibility of the absence of an electrical panel as such, when the wire goes directly from the meter to the main junction box - a faulty contact may be in it.

Two-phase socket is a common fault where both sockets of the socket are 220 V-phase. In fact, we are not talking about two, but about one phase - of the same name, which can be checked with the power of a special device - a multimeter. In this article, we will figure out why there are two phases in the outlet, what dangers this problem poses and how to fix it.

A bit of theory

Electric current is in a closed circuit when the voltage is sent to the consumer. If the circuit is opened (for example, by a switch of a lamp connected to a phase wire), the glow is impossible. In this case, the phase potential reaches the switch, as well as zero (to the nearby contact of each lamp base).

The short name of the wires is phase and zero. When the switch is turned on, the phase potential reaches the distant lamp contact and through the resistance of the filament creates a current flowing through the wires of the closed circuit from the transformer.

A generator that produces electrical energy consists of several large coils of wires in which current is excited by the action of permanent magnets. The coils are combined with each other so that one end of each is allocated to the connection with the ground (ground). One end from each coil acts as insulated conductors directed to consumers. Thus, an ungrounded wire is called a phase, and a grounded wire is called zero.

In any outlet there is one phase and zero. Electrical appliances operate on a single-phase principle. However, the power plant transmits three phases and zero. Two phases remain in switchboards, and one phase is evenly distributed to consumers.

You can find out where the phase is by using a voltage indicator. A glow will appear on the contact farthest from the lamp socket. At the same time, there should be no glow at the near contact - this is zero.

Wrong connection

Two phases in the outlet is a common problem in old houses. This problem occurs because of the following common error: phase break, not zero. In this case, the lighting worked, but there was a risk of electrical injury when replacing the lamp, since it was always at phase potential.

If a capacitive indicator is used in the described case, the device emits light on both contacts of the lamp base and only on one of them - the switch. The problem is that the phase potential reaches the broken circuit from the electrical panel of the apartment to the non-working contact of the switch. In this case, there are no conditions for the flow of current due to the fact that the circuit is open. In professional language, such a problem is called a zero break.

The problem can manifest itself in the outlet. This will happen if you disconnect the zero at the input and the appearance of a parallel circuit with a connected resistance.

The fault is also found in the simplified wiring diagram, where the separation of sockets and lighting into power chains is ignored. In this case, the protective role is assigned to electrical plugs or circuit breakers.

In the event of a zero break at the input of the outlet, which is located, for example, in the kitchen, and the light switch in another room is turned on, the capacitive indicator will also show 2 phases in the outlet.

Socket voltage rating

Phase potential can cause the capacitive indicator lamp to glow, but zero cannot. This feature confuses many people. To correctly assess the situation, you need a device that indicates exactly the difference in potentials, and not one of them.

The following devices are used to determine the potential difference:

It should be noted that all multimeters, which are combined electrical appliances to help a home electrician, can work in voltmeter mode. If the probes of the device are placed on the contacts of a faulty outlet, the electric potential will be zero, which indicates the absence of a potential difference. Therefore, the normal operation of electrical appliances is impossible. A normal voltage indicator will be noted only between the phase and zero of a good electrical wiring.

So, the voltmeter does not determine the voltage between the same phase, since it is simply not there. Voltage is available in a network with one phase only between zero and phase.

Features of the three-phase network

An equivalent phase voltage is sent to all housing units of an apartment building. This indicator is 220 V. The voltage is switched to the power supply in a random order. In the circuit, there are only currents from the end of the generator, which flow through the phase wires to the load and come back through the neutral wire. The current at zero is the sum of the currents of the three phases. Phase voltage may differ within the technical regulations.

Zero Break Problems

The gap upsets the balance in the system, the flow of different-phase currents stops, and the voltage in the system changes.

As an example of how two phases can occur in an outlet, consider circuit AB. Line-to-line voltage is sent to rooms A and B. The resistance is connected in series and includes two components. Due to the total resistance (Ra + Rb), a current (Lab) flows through the circuit, which is calculated according to Ohm's law. This indicator is common for both rooms.

The decrease in voltage in the premises becomes unequal - it depends on the level of resistance inherent in operating electrical appliances. If all household appliances are turned on in one of the apartments, and the other consumption indicator is lower, all 380 V will be in an apartment with a higher current, which will lead to equipment failure, therefore 2 phases are not allowed in the outlet.

You can reduce the risk of damage to electrical equipment by using a voltage-monitoring relay. Such a relay is installed in the apartment electrical panel. The relay is in automatic mode. Its task is to turn off the electricity supply in time in case of an emergency.

Possible problems

The following are the most common problems associated with a zero break and the presence of two phases in the outlet.

Mains break with one phase

A zero break can occur anywhere in the wiring, but most often the problem appears where the electrician switched the wires to:

allocate apartments;
soldering box;
socket.

Another option is the destruction of the insulating layer of the wiring and the breakage of the zero core, after which a contact is formed on the phase.

Gap in the electrical panel of the apartment

Two phases in the outlet can occur in the following areas:

introductory automatic switch;
electric meter;
zero bus.

The essence of the problem may lie in a faulty contact with the wire, which can occur due to:

dirt on the work surface;
loose screw;
tears of metal conductors of wires.

These problems lead to an increase in resistance at the transition point and overheating of the section. As a result, the metal is deformed and the line breaks. As a result, the integrity of the wire is violated, the voltage disappears, but the phase remains. If there is at least a single working switch or any electrical appliance is connected to one of the sockets, the phase potential will be directed to the second contacts of all sockets along the neutral bus. In this case, to detect a malfunction, an inspection of all damaged areas will be required.

Break in junction box

Two phases in the outlet can manifest themselves in a room where there is a soldering box with a torn off zero. In this case, in all other rooms there will be normal voltage.

In obsolete junction boxes, the wires are connected with twists and protected with insulating tapes. In the zero region, more connections are needed, as a result of which the twist came out thicker. It is from here that the ringing of the circuit should begin when searching for the zero potential.

A zero break also happens in the wire that connects the junction boxes. To replace the cable, you will need to punch through the wall. Such work is characterized by high labor costs, and therefore the creation of a new highway looks much more rational.

Open and short to phase

A break in the socket block can occur when drilling walls, hammering nails, screwing in self-tapping screws. Such manipulations can lead to a violation of the integrity of the laid electrical wiring and the occurrence of short circuits. The two phases in the socket are detected on the two contacts of the socket without the presence of additional bypass circuits. You can fix the problem by replacing the broken wiring section.

Break in the network with three phases

In this case, a second phase potential enters the single-phase home network, and the current supplied to household electrical equipment rises sharply - up to 380 V. The electrical distribution company is usually the culprit of this problem, and electricity consumers bear the main damage.

As an example, we can analyze the situation in which there is a break in the network to which a private house is connected. Wires are usually located above the ground, and the lines are characterized by a significant length. It is this arrangement of power lines that is their most vulnerable point, since communications are highly susceptible to external factors. It is safer, in terms of ensuring the stability of energy supplies, to place the cable underground. This method of delivering electricity is often used to connect multi-apartment buildings.

Hello, dear readers and guests of the Electrician's Notes website.

Today's article will be devoted to a common malfunction that can occur in the wiring of your apartment or cottage. It will be about how two phases can appear in a conventional outlet. For an experienced electrician, it will not be difficult to determine the cause of this malfunction, but for ordinary citizens, this can be confusing.

I'll go straight to an example.

Suppose you have plugged in an electric kettle, but it does not work.

First of all, you need to check. We check in one pole (socket) of the socket - the pointer shows the phase.

The photo does not clearly show how the indicator light of a single-pole indicator is lit, so I highlighted the place of glow in red.

We check in the second pole (socket) of the socket - and the pointer also shows the phase.

How so? Why is there two phases in the socket?

Reasons for the appearance of two phases in the outlet. How to eliminate?

No need to be scared. In fact, these are not two phases, but one phase, i.e. eponymous. This can be easily checked by - it will show "0".

Then the question arises - how can this happen? In fact, there can be several reasons, I will list the most frequent ones.

1. Breakage of the neutral conductor N at the entrance to the apartment

Consider an example on a simple diagram, which I have specially compiled for you.

The phase from the input cable is connected to circuit breakers 16 (A) and 10 (A). The first machine is installed in the outlet line, and the second - on the lighting line. The input zero is connected to the N busbar, and the protective PE conductor is connected directly to the socket. Hope you all remember.

An electric kettle is connected to the outlet, and as a lamp for 26 (W).

Here is a wiring diagram of what I put together above:

I remind you!!! In normal mode, one pole (socket) of the socket should have a phase, and the other should have zero.

Here is the working state of the assembled circuit. The electric kettle is on, the lighting lamp is on.

If this is neglected, then hidden electrical wiring can be accidentally damaged. In this case, three types of malfunction can occur:

closure of the cores of the cable (wires) to each other
breakage of all cable cores (wires) in the wall
zero core break

In the first case, the circuit breaker of this line will trip, after which it cannot be turned on again, because. short circuit must be removed. In the second case, the automatic switch will work, after which it can be turned on, although not a single electrical device will work. In the third case, two phases will appear in the outlet.

Here, the way out of the situation is as follows: either lay a new line, for example, in a cable channel, or gouge the damage site and connect the wires.

5. Rodents

Watch the video for this article:

Addition: I ask the malfunction discussed in this article not to be confused with. There, the consequences will be much more dire.

P.S. This concludes my article. I hope now you know what to do and where to look for a malfunction if electrical appliances stop working and two phases appear in the outlet. Thanks for attention.

Even the owner of a house or apartment, far from electrical engineering, is simply obliged to have a minimum set of knowledge and skills regarding the operation of a home electrical network. And that doesn't just mean plugging in a plug, flipping a switch, or changing a burned-out light bulb. It is necessary to have an idea about carrying out the simplest network diagnostics, about identifying obvious problems in its operation. Indeed, some of them can be completely corrected on their own, without resorting to calling a specialist.

One of the simplest checks that is resorted to when lighting or household appliances suddenly turn off, but remain on, is to check for the presence of a phase. Most owners have an indicator screwdriver, and the process itself takes a matter of minutes. And everything is more or less clear when such a “revision” shows the absence of a phase - it can simply be power outages. But sometimes the situation is different - the indicator lights up in both sockets of the socket! It is clear that there are no problems with the supply. But what's the matter, why are there two phases in the outlet?

Let's look at the reasons for this situation, with possible ways to eliminate such malfunctions.

In which socket should there be a phase in the socket?

Many will find this question ridiculous. But, nevertheless, with this one should immediately make due certainty, since the publication is designed for completely inexperienced users. And they, no, no, and ambiguities slip through. This, probably, explains the considerable number of search queries like “in which hole of the outlet to look for the phase”? (It would probably be more correct to say “in which nest”).

So, we are looking at a single-phase socket of those standards that can be found in Russian homes - most often this type FROM or type F.

Type FROM- This is the most common socket with two sockets for the contact pins of the plug. There must be a phase contact in one socket ( L) , in the second – zero ( N). And no more embellishments.

Type F has recently been increasingly replacing type C. This is due to the fact that in urban new buildings the electrical wiring system was initially planned with a ground loop RE. It is becoming the norm to equip reliable grounding in private homes. This is due to the requirements for ensuring the safety of the operation of household electrical appliances. Take a look at the mains plugs of your home appliances - in the vast majority of cases, modern appliances “ask” to be connected to the ground loop as well. Therefore, standard F sockets provide an additional contact specifically for this purpose. It consists of two curly spring-loaded plates located exactly in the center of the outlet at the top and bottom.

But no matter what the outlet, there must definitely be a phase and zero in its sockets. No other options are provided. The presence of a ground contact does not change this rule in any way.

For single-phase household appliances operating from a 220 V network, the relative position of the phase and zero in the vast majority of cases does not matter. Yes, and the owners during operation often insert the plug into the outlet, completely without thinking about its spatial position - in short, how it will turn out. And it has no effect on the performance of the equipment.

Note that there are exceptions to this as well. Some appliances, such as air conditioning or heating systems with built-in thermostatic controls, require an unambiguous location of phase and neutral on their terminal block. But, as a rule, these devices are stationary installations, and are connected not through sockets, but directly to dedicated wiring lines connected to them.

So on which socket to look for a phase when checking sockets?

The answer is categorical - you should always check both sockets. No need to rely on supposedly existing standards for the location of contacts. First of all, because such standards do not exist at all.

What they say about the correct position of the phase in the right socket is not fixed by anyone and nowhere. Yes, many "old-school" electricians observe the "polarity" of sockets by actually connecting the phase to the right terminal when looking at the socket from the front. But this, rather, can be considered a kind of "rule of good manners" that singles out specialists with a professional approach.

It is clear that with an ordered arrangement of the phase and zero, it is easier to deal with malfunctions and diagnose the home electrical network. Moreover, there are special devices that allow you to very quickly and accurately diagnose the outlet line - the presence of breaks or leaks, the correct connection of contacts, etc. This tester is enough to insert into the socket and turn it on.

So, the layout of such devices is designed specifically for the right location of the phase socket. That is, when the tester is properly plugged into the outlet, all the inscriptions are readable. The illustration above shows an example of such a device, and the phase LED is highlighted by an arrow - it is located on the right. Nothing, of course, prevents turning on the tester and “upside down” - it will perfectly cope with the task even when the phase is on the left. But, nevertheless, it is precisely such a “correct” layout that still says something ...

But, again, don't rely blindly on these unspoken rules. Always, in any case, when checking the phase, both sockets should be checked.

How to determine where the phase is, and where is zero in the outlet?

Any owner of a house or apartment will surely have to deal with such a “diagnostic operation”. The check is carried out with the help of inexpensive devices, which you should definitely have in your tool "arsenal".

And in the course of checking both nests, when the “light” disappears, the owner can expect a very unexpected and rather unpleasant “surprise”. Just about this and will be discussed further.

Why can two phases appear in an outlet?

So, in the house (apartment) the lighting suddenly went out, the electrical appliances stopped working. To begin with, the owner makes sure that the protective devices have not turned off. Then he takes an indicator screwdriver and starts checking for the presence of a phase. The most convenient place for this, of course, is the outlet. And then, to his surprise, the indicator lights up equally brightly in both of its sockets. Everything suggests that the outlet has two phases. But how can this be?

If in such a situation you measure the voltage between the two contacts of the socket, it will show a zero value. Why - yes, it's just one and the same phase! There is simply nowhere else to come from, once a single-phase power line enters the house (apartment). And voltage is, as you know, the potential difference that ensures the occurrence of electric current. There is no difference - there is no current, so all the devices turned off.

Why might this happen? The reason for the appearance of two phases on the outlet is most often a break in the neutral wire.

We look again at the diagram, but only - somewhat modified.

The diagram shows the usual, so to speak, "regular" homework. For example, only two sockets are taken. The first is in which the phase and zero are determined. The second - with the connected load. The figure conventionally shows a light bulb, but it can be any household appliance in the on state.

The movement of electric current passes away from a contact with a large potential to a smaller one. That is, from phase to zero. The arrows show the "trajectory" of the current with the load on - from the machine along the phase wire, bypassing the junction boxes along the way. Further - through the outlet (or switch - for most stationary lighting fixtures), through the load. And then - in the opposite direction, but already along the neutral wire to the zero bus and further, through the input machine - to the access or street switchboard. But there is already a zone of responsibility of the energy supply or operating company - then we do not care about it.

And now let's simulate a situation when, say, an open has occurred on the zero bus or on the terminal of the input automaton. For example, during installation, the clamping screws were not tightened enough or other negligence was made, such as wires installed in tightness. By the way, this is where most often lies the cause of such malfunctions of the home network.

Imagine that the neutral wire contact is lost at the circuit breaker terminal.

Although the load is on, no current can flow. The common power circuit is open at the circuit breaker terminal. But what happens instead? Since the load remains on, its internal circuit is a conductor. This can be the primary coil of the power supply transformer, the filament of a lamp, the heating element of a boiler, iron, electric stove, etc. By itself, the device is inactive - there is no current. But through it, through its internal circuit connected to a common network, the phase potential "flows" through the neutral wires. And if you now check the socket with an indicator screwdriver, then in both sockets it will show the phase.

The diagram shows only one line, protected by a circuit breaker. In fact, there are usually several of them. But if a zero break occurred before the zero bus, then a two-phase pattern will be observed in all outlets.

By the way, this situation is very common in old houses or apartments. That is, where the old switchboards with fuse plugs, and not circuit breakers, are still preserved. Burnout of the “zero” plug is quite common. And every time there will be such a picture. So, if possible, it is worth upgrading your home (apartment) network as soon as possible. That is, install a paired automaton at the input, after which the phase is distributed to a group of automata along different lines, and zero is connected to a common zero bus. The probability of "loss" of zero with such a scheme is significantly reduced.

Probably, from the above, it should already be clear that if, after detecting such an accident, the entire load (all household appliances and lighting) is disconnected from the network, then the “two-phase effect” will disappear by itself. It's just that the phase will not have a flow path to the neutral wire. True, the performance of the system from this will not be restored in any way. All the same, it is necessary to deal with the cause, to look for a section of the cliff.

And for this, it is desirable to immediately localize the damaged section of the home network. After all, “universal two-phase” will be observed only if the break occurred even before the zero bus. That is, on the neutral wire directly approaching it from the machine.

This is easy to check. Some simple household appliance is connected to the outlet of the group closest to the switchboard. Let it be even an ordinary iron or a fan, it doesn't matter. The main thing is that it should be in the on position. Its role is only to become a "bridge" for the phase. Then an indicator screwdriver is taken, and the adjacent sockets of this group are sequentially checked, and then all the socket groups in the apartment (house) without exception. If two phases “hang” in all sockets, the matter is clear, a zero break should be sought in the shield. Usually this does not cause problems. As a rule, such a defect is easily detected and quickly eliminated. This is “treated” by stripping and tightening the contacts on the terminals (a real wire break in the shield is almost unbelievable). Naturally, all work in the electrical panel must be carried out with the introductory machine turned off.

But if the check did not give such complete clarity, then, most likely, the zero break is local. And the review should continue. The load is transferred to the socket of the next junction box. The actions are repeated: first, neighboring sockets, then - further along the network. Sooner or later there will be clarity - on which line or in which junction box there is a zero gap.

It also happens that only one conductor was unreliably fixed on the zero bus, which, as part of the cable, then goes to some room or to a specific socket group. Then, of course, the area of problems will extend only to this line. All other sockets and lighting devices connected to other lines will be in working order.

Video: Why are there two phases on the socket contacts?

And even on one line with two or more junction boxes, localization of such damage is possible. As it is probably already clear, the reason for this may be a break in the neutral conductor in the junction box. In this case, all other connection points of the same line, but switched on other junction boxes, will remain in working order.

And this happens most often or due to dilapidated wiring. Or due to poor-quality wiring in the box. This is especially true for those houses or apartments where aluminum wiring remains in operation. Aluminum is a very soft metal and even, as they say, "floating". That is, even seemingly reliable twists or terminal connections begin to weaken and require tightening. In addition, a layer of oxides on its surface creates considerable additional resistance. And this leads to heating of the connections, the appearance of sparks and, as a result, the complete loss of contact. So this is another reason to think about a complete change in wiring to high-quality copper cables.

What should be the cable for high-quality wiring in an apartment or house?

The answer is unequivocal - only copper. By the way, the current, legislatively approved norms and rules speak categorically about the same. How to do it right - read in a special publication of our portal.

By the way, even with copper wires, some craftsmen are weird in such a way that it is simply amazing how the home electrical network still works. So checking the junction boxes and bringing them into full order is one of the key measures to prevent zero from disappearing.

It is much more difficult to find a place for a zero break if it occurred in hidden sections of the wiring embedded in the wall. Here you will have to work harder to localize a possible emergency segment, to perform ringing of hidden areas. Yes, and the restoration will be associated with more extensive work - opening the old wiring and replacing it.

True, the wire itself, enclosed in the wall, breaks off or breaks extremely rarely. More often this is facilitated by the ill-considered actions of the owners of the apartment. In particular, drilling holes in walls in clearly dangerous areas, without first checking for wiring.

In our rapidly developing information age, one has to keep abreast of all events, and the desire to learn more and apply knowledge in practice is growing more and more. Even if the light suddenly went out in the apartment or the socket did not work, we try to find the reasons ourselves and find a solution to why this happens. It must be remembered that when working with electricity, it is important to observe safety precautions, do only what you are absolutely sure of and remember that if you handle electricity carelessly, you can feel how the current and voltage of 220v beats, which can lead to sad consequences.

The socket in the apartment does not work: what to do

There is one fault in the wiring that baffles novice electricians. Although, at first glance, everything is in order: the machines are turned on, the wiring is intact, but the electrical appliances have stopped working, and the indicator on the screwdriver is on, thereby indicating the presence of two phases on both wires. This also indicates that zero has disappeared. This phenomenon is not uncommon, but an inexperienced electrician will make them scratch their heads.

If your socket has stopped working, then an indicator screwdriver will help you check the absence of zero and the presence of another phase in the socket.

This situation has several consequences: all appliances will remain working, or equipment and fixtures will simply burn out. The thing is that phases are of the same name, but there are opposite ones. An ordinary household appliance called a tester will help us deal with the type of phase in the outlet. It can be used to check various electrical parameters. To do this, you need to connect the device to the outlet and measure the voltage between the two phases. If voltage is present, the phases are opposite, and if it is absent, then the phase is of the same name.

Why there are two phases in the outlet: a simple explanation

To get an answer to this question, it’s worth a little understanding of how electricity comes to our apartments. Four wires go from the main electrical line to the substation of high-rise buildings: zero and three phases - this is a three-phase network with a voltage of 380 volts. Then the phases are separated in different directions of the courtyard. One phase and one more neutral wire come to each switchboard of the entrance. This is a single-phase network and it has a voltage of 220 volts. 2 wires come from the driveway switchboard to the apartments (in new buildings, one more wire is added - grounding).

Only one phase is supplied to the apartment through an electric meter and a shield of machines.

Consider a situation where we wanted to hang a shelf in a room on the wall, connected a drill and started drilling the wall. Suddenly, the machine on the shield knocks out, the light in the apartment goes out and the drill stops working. However, with the help of an indicator screwdriver, we found that there are two phases in the socket. Most likely, when drilling, we touched the wiring with a drill, and thus we managed to close 2 wires, which caused a short circuit and the operation of the machines. Thus, we received the phase of the same name in our apartment. To eliminate this malfunction, it is necessary to de-energize the apartment, examine the place where the drilling was carried out and connect the broken wire. In private sectors, where power lines are located on poles, one of the phases may be shorted to the neutral wire when they come into contact. In this case, two opposite phases may appear in houses and this can lead to failure of household appliances.

There are two phases in the outlet: what to do

The presence of a phase on the neutral wire is due to the fact that the phase is under constant load: a refrigerator, a light bulb or other electrical appliance. The electrical wiring in houses and apartments is designed so that all wires are closed in the electrical panel to the zero bus. To make sure of this, it is enough to turn off all electrical appliances. So, all your devices are off, and a phase still appears on the neutral wire.

Universal solution methods:

Turn off all electricity in the apartment;
Check that each switch is set to the "off" position;
Unplug all household appliances from outlets, no matter how many you have;
Visually diagnose a malfunction on the panel or at the place of work;
Call qualified electricians.

In any case, for a reliable diagnosis of the true cause and troubleshooting, you need to resort to qualified help.

Two phases in the outlet: causes and solutions

There are a number of the most likely reasons for the occurrence of two phases in the outlet - from the banal burnout of the safety plug or turning off the circuit breaker on the electrical panel, to the short circuit of the wires and the appearance of induced currents.

The most common causes of two phases are:

Strong wind or tree branches shorted the wires;
A short circuit, in which the wire braid melts and they close;
Zero is closed to the phase, for example, when drilling;
Induced current - due to the presence of nearby high-voltage power lines;
Overvoltage - increase (up to 380 Volts) or decrease (up to 40 Volts) voltage values;
In the internal wiring system, the neutral wire burned out.

When troubleshooting, you need to carefully analyze and consider all possible cases.

Reasons for the appearance: two phases in the outlet (video)

Remember, electricity punishes incompetence. If you do not know what to do, or if you have any doubts about the wiring or electrical appliances, call the professionals immediately. This will help to avoid unwanted consequences in more than half of the cases, and can help save lives and property.

In the event of electrical wiring malfunctions, a situation may sometimes arise when the voltage indicator will show you two phases in the outlet. For novice electricians, this situation can be shocking, but in fact there is nothing complicated here. Consider why there may be two phases in the outlet, having analyzed in detail the main causes of electrical wiring faults.

Electrical wiring damage

Hidden wiring is less protected from breaks than open wiring, which is clearly visible. No one will think of driving a nail through a cable channel or corrugation. And no one is safe from drilling holes in the place where the wire passes. Moreover, sometimes builders lay them in completely unexpected places.
Devices for determining hidden wiring are expensive, and not everyone can afford it. Yes, and buying such a device knowing that it may never be needed is a waste of money.

Finding hidden wiring with a special tool

In addition, in a hot impulse to immediately hang a new carpet on the wall, they often forget about the presence of electrical wiring and drill the wall next to the junction box, not paying attention to it.
Depending on the location of the damage, you can leave without electricity either the entire apartment, or some section of it, or one single outlet. You may not even notice it. Modern ones are famous for their high speed and localize a short circuit almost instantly. Even a spark won't get through. If the wiring is protected by an old-style switch or plugs, the effect will be noticeable, with smoke and sparks.
Neither hidden nor external electrical wiring is insured against another type of damage. These are violations of contacts in junction boxes. The main reason for such a defect is a poor-quality connection of wires, which warmed up under load, oxidized and fell apart. An additional sign for its search is the characteristic smell of burnt insulation near the box with damage.
There is another one with the help of twisting, forming a galvanic pair with each other. Under the action of natural air humidity and heating by the load current passing through the connection, intensive oxidation of the contact surfaces occurs, leading to a break.
If you yourself accidentally damaged your electrical wiring, you will certainly find a break in the wake of your own activity. If you were asked to deal with problems in someone else's apartment or the break occurred for other reasons, then a few tips will not hurt.

Option 1. Breakage of the phase conductor

In this case, the indicator in the outlet will not show anything. The fault is localized by checking the presence of a phase in the junction boxes from the faulty socket to the group shield.

Option 2. Breakage of the neutral conductor

In this case, the indicator will show two phases in the outlet. In this case, electrical appliances connected to this outlet, as well as to some others or all at once, do not work. The presence of the second “phase” is explained simply: this is the same phase, but it comes to the place of the broken zero through the load resistance. It is used as household electrical appliances connected to a power supply with a broken zero.
It is enough to disconnect all consumers from the sockets, and the additional "phase" will disappear.
Then it is necessary to calculate all the sockets left without voltage by connecting a voltmeter, a two-pole voltage indicator or a control load to them. A single-pole indicator is not suitable for this case, because the phase is everywhere. Do not use a light bulb with wires to search for breaks. If you run into 380 V somewhere, it will explode in your hands with all the ensuing consequences.
Having determined the remaining outlets out of work, you need to figure out how the hidden wiring is located and calculate the area of \u200b\u200bpossible damage. With external wiring, everything will be much easier.

Break of the neutral wire

Option 3. Breakage of the neutral conductor with a short circuit to the phase

This is a special case of the second option; the outlet will also be determined by the “two-phase” indicator. When all electrical appliances are turned off, the second "phase" does not disappear.
Theoretically, this cannot happen in a junction box and usually happens when drilling walls and driving nails. When it hits a two-core wire, called "noodles", the drill can deform it so that the broken neutral conductor melts or simply touches the phase conductor.
Sometimes nails or dowels, falling exactly between the wires of the "noodles", arrange a short circuit. The neutral conductor burns out or breaks, and the nail provides contact of its remaining part with the phase conductor. It is advisable to start searching for such malfunctions by touching all the metal fasteners in the walls with the indicator. If a phase is found on one of them - "dig here."
In all other respects, the search for damage is no different from option No. 2.

Option 4. Protection devices

Civilization has not yet reached all houses and apartments, and this case is still quite possible. Previously, two fuses of the “cork” type were installed at the input. They did not always burn out when they closed at the same time. If the fuse in the neutral wire is blown, then the phase will also go through the load through all the sockets.
Defect localization is the process of finding a place for a possible short circuit. You need to find out why the fuse blew. To do this, it is necessary to disconnect from the network all electrical appliances, lighting, without exception, screw in a new fuse. If it fails again, look for a short circuit in the wiring, if not, look for a damaged electrical appliance.
In modern networks, this is theoretically possible if two automatic switches are installed at the input, replacing the traffic jams that once stood in this place. Such a power supply scheme in itself is a violation of the PUE - there should not be switching devices in the neutral conductor circuits of two-wire networks. And if it is, then zero must be turned off simultaneously with the phase wire, that is, the machine must be bipolar.
When using a two-pole circuit breaker, the appearance of "two phases" in the outlet is possible if it "breaks" the pole through which zero passes. This may be due to a defective switch or insufficient tightening of the terminal block.

A two-pole circuit breaker must be used for protection.

Option 5. Mains failures

All the cases considered so far implied the presence of the same phase on the power wires. The voltmeter connected to the outlet indicates the absence of voltage. But why can a situation occur when it shows 380 V?
This is possible and, unfortunately, not so rare. The neutral conductor can break anywhere: at a supply substation or a group floor shield, a switchgear at the input of an apartment building.
At the same time, the power supply to consumers does not stop, but the voltages are redistributed over the phases as follows: the voltage will be the largest on the most unloaded phase. On the most loaded - the smallest. In the worst case, on a phase with a very small or completely absent load, the voltage will increase to 380 V. All electrical appliances connected to the network at that moment will fail.

Another option for the appearance of two different phases in the outlet is the closure of the phase and neutral wires of the power lines to each other. If in the area from the power source to the fault one of the connections fails and burns out, the appearance of two phases will become stable. The consequences for consumers are the same.
The case is typical in that you will not have time to admire the indicator readings, you will not need it. Everything will happen very quickly. As sad practice has shown, not all protective devices of household appliances have time to work out properly. Some electrical appliances catch fire and start a fire.
Searching for the cause and place of a break or short circuit is the business of electricians from a network company. It remains for the consumer to calculate the losses and sue this company.
To protect your electrical appliances from such troubles, you need to install a voltage control relay at the entrance to the house (apartment). Its main task: when the controlled value goes beyond the specified limits, turn off the entire load, and when the nominal value is restored, turn it back on with a time delay.

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