Definition of zero wire. How to define phase and zero indicator screwdriver or multimeter. Features of the definition of phase and zero

Carrying out repair work in any room, an important point is to equip this room with electricity. In addition to the wiring, you should not forget about the need to install sockets and switches, with which lighting control will occur. Then a fairly important point will be found a phase, zero and grounding conductor of the system.

For professional installers, this task is very simple, which you can not say about ordinary alone, which can not always cope with such a task. However, the search for phase and zero is not so complex as difficult as it may seem initially, it includes several methods for determining.

It should be understood that the wiring in the apartment usually has a voltage of 220V, since it involves connecting to zero conductor and to one of the phases. At the same time, it is obligatory, which makes the electrification of the room safe for the inhabitants.

Content:

What is a phase and zero in electricity for a beginner

To catch the principle of finding the phase and zero on the network, you should first define for yourself, which means the terms of the terms that may sound as completely incomprehensible concepts. Any system, regardless of its length, consists of three phases, and also concerns low-voltage lines, whose task is to eat residential buildings.

Between two any phases, a linear voltage occurs, which is 380V. However, the household network voltage is 220V, the main task is the appearance of the voltage required for the network. For this purpose, a zero wire is present in any network, which, in combination with any phase, forms the potential difference in 200V, which will be a phase voltage.

Zero in the electrical circuit is called the conductor, which is connected to the light circuit and is used to create a load from the phase. This phase is connected to the opposite end of the winding on TP. Thus, in a standard outlet, for clarity, one entrance is taken over the phase, and the second for zero.

If we speak a simpler language, the phase is the wire for which the current comes. By zero wire, the current returns back to the source. Depending on the number of phases, the system has several wires. Suppose, in the three-phase chain there are three phase wires and one inverse, zero.

Color designation. Not rarely many are interested in the question of what color the wire is zero land, how to determine where which wire is often provided with the help of color demarulations used in the electrician. However, this method will work only if the wiring is really fulfilled in all the rules. The zero wire isolation is usually denoted by blue or blue, the earth combines two coloring in itself - green and yellow. The phase wire according to the rules is indicated in brown, white or black.

Phase designation and zero letters . In addition to color designations, the locked wire marking is possible. The phase is usually denoted by the Latin letter "L" and the zero wire is made to marked with the letter "N". In addition, the grounding has a grounding, denoting which is accepted by the letter "G".

How to determine the phase and zero indicator screwdriver

For the location of the phase and zero on the network you can use various tools. The most successful invention to help beginner electricians is an indicator screwdriver with special sensitive elements and a reflector indicator.

Check the phase and zero in the network using a screwdriver is easier than simple. The screwdriver should be held between a large and middle finger. It is not allowed to concern the uninsulated part of the screwdriver sting. Finger index should be put on a metal round ledge at the end of the handle.

Determine the principle of the indicator screwdriver is not difficult, there is a special lamp inside it, as well as a resistor, which is resistance. The lamp lights up if the chain is closed. Thanks to the resistance, you can not be afraid of lesion to the current during the inspection, since it removes its value to the minimum indicator.

How to find out where the phase and where zero in the outlet indicator probe video

Find zero such a screwdriver, respectively, will not work. In addition, this method often gives a failure due to not too good sensitivity. As a result, the indicator screwdriver, reacting to the tip, can give the voltage where it is absolutely no.

How to determine the phase and zero multimeter

In addition to the use of an indicator screwdriver, it is possible, which will also allow to find out where the phase and where zero on the network. The prerequisite for its use is the preliminary stripping of the wires.

On the device, before use, you want to set the value of the measurement limit of the alternating current, the value of which must exceed 220V. It should also be focused on the labeling of the nests where the appliance probes are included. For this type of verification, the probe will be required included in the "V" labeling slot.

The check itself consists in touching the probe to one of the wires, while following the instrument testimony. If the multimeter identifies any voltage, then this wire is a phase. If another wire shows the zero value, then this is, respectively, the zero wire.

The device for operation can be used by any type - the arrow or with a digital indicator. In any case, an important point will be the observance of security measures, as well as the correct indication by the instrument of testimony from the wires. The accuracy of this device is usually higher than the indicator screwdriver.

The main rule when using the multimeter is a ban on the simultaneous touch of the phase and the grounding circuit. Such negligence can lead to a short circuit and, as a result, to traumatic burns.

How to determine the phase and zero without instruments

Despite the widespread distribution of instrumentation methods for determining the phase and zero on the network, the necessary device may be at hand, which will make the right conclusion. In this case, the improper detection of wires in the network "on the eye" can lead to sufficiently dangerous consequences.

The first method allows you to cope with this task, was described in one of the partitions above. It consists in finding wires, depending on the color of their isolation, as well as on the marking. However, this will be true only if the wiring was performed according to all the rules.

The second way to determine them is to make the so-called warning light, applying a screwdriver. This requires a simple incandescent lamp and two segments of the wire, about 50 centimeters. The conductors of the wires should be connected to the light bulb, while the second end of one of the wires should be touched on the heating pipes (stripped), and the second to touch the "nicknamed" wires. That wire, when touching the light lights up, is a phase.

Phase definition without indicator and video device

It is worth paying attention to the fact that the described method is very dangerous and can lead to a shock during its use. In no case is not recommended to apply it if you have limit voltage in the network, and the bare wires cannot be concerned.

An alternative incandescent bulb can be neon light bulb, which will find the polarity of the system.

In conclusion, it should be noted that the answer to the question: how to determine the phase and zero has several solutions. Namely: indicator screwdriver, multimeter, and can also be without appliances. It all depends on the possibilities and availability of devices at hand. Mandatory is the observance of all security measures when working with electricity.

When connecting various electrical devices (socket or switch), it is not necessary to take into account the polarity of the conductors. But what to do if the wiring used in the house is three-core and does not have color marking, and the devices must be connected to the grounding conductor. To do this, there are several ways to check which of the wires is a phase, zero or grounding.

Determination of the phase and zero without instruments

There are situations when it is necessary to find out which wire phase, and what zero. For example, to ensure the normal operation of the lighting device, in the gap (through the switch) and the parent wire, and the zero is laid directly to the lighting device. Currently, wiring in homes and apartments is laid by three-core wires, which are divided into three types.

Types of conductors:

Phase;
Zero;
Ground.

Distinguish in the wiring phase from zero seems possible visually. But for this, one important condition should be observed. Wiring in the house or apartment must be made using multi-colored conductors.

Phase conductor according to the GOST rules, must be marked with the following colors: black, white, brown, purple, turquoise, red, gray, pink and orange.

Note! The most common colors encountered for marking phase wires is white, brown and pink.

Zero conductor is easy to find, as it is always marked with blue. Grounding wire has a yellow color.

It is worth noting that the electric current that is supplied to the residential sectors is variable, therefore the polarity of the electrical appliances does not matter. The correctness of the connection is important only for hardware operating equipment.

Phase and zero in the outlet: how to determine the indicator screwdriver

The easiest way to determine the phase conductor is the use of a conventional indicator screwdriver. Currently, a huge amount of instrument data is presented on the market.

Types of indicators:

With neon indicator;
With the use of LEDs.

The indicator using the neon light bulb is made in the form of a dielectric housing, inside which an neon lamp is located with a resistor connected to it.

The design of the LED indicators is represented as a conventional screwdriver, inside which the LED, chip and several small batteries are located. These devices, having different characteristics, are similar on the principle of action.

It's important to know! Determine the phase conductor seems possible only if there is a voltage in the electrical network.

In order to find the phase in the wiring, you must do the following. The conductor removes the voltage. This is done by turning off the protective automaton in the electrical panel.

After that, the wires are cleaned of isolation for a length of approximately 1 - 2 cm. The ends of the wire are bred to the sides, it will help to avoid short circuit between these conductors.

A voltage is supplied to the wire, turning on the protective machine. Then, the metal part of the indicator is applied alternately to each and wires. The light indicator will indicate the operating phase in the wiring.

It is worth noting that some devices due to their constructive features can be equipped with a metal plate at the top. To properly define the phase conductor, it is not necessary to concern.

How to find phase, zero and grounding multimeter

If the phase conductor is easy to detect using an indicator screwdriver, then zero and grounding determine with its help is not possible. Since these conductors do not affect the performance of the indicator. In this case, it makes sense to use a multimeter.

To determine, it will be necessary:

Multimeter (tester);
The presence of voltage is 220 V.

The definition of each of the conductors should be started with the preparation of the device. The plugs under the name COM and V are plugged.

If you need to find a phase wire, then for this by turning the switch, on the multimeter it is necessary to select the variable current measurement value in the range of over 220 volts. After that, the dipstick that is connected to the NOTE with the name V, alternately touches all the conductors. When touches the phase conductor, the values \u200b\u200bfrom 8 to 15 volts will appear on the device display. Zero and grounding conductor These readings will not change.

Note! When working with wiring under voltage, be sure to follow safety rules.

After the phase conductor is found, you can search for zero. To do this, with any probe multimeter touch the phase conductor, another contact with any of the other conductors. On the zero conductor will indicate the device displayed on a 220 volts appeared on the display.

The third conductor will be grounding. Indications on the display when touching the phase and grounding wire is always below the value of 220 volt.

Non-standard ways: how to determine the phase in the wiring

The fact that these methods are unsafe. It is recommended to apply them only subject to all necessary security measures.

Methods for determining:

Homemade check light;
Potato.

For the manufacture of the control light, a regular cartridge will be required, an incandescent lamp of any kindness and meter wire. First, we clean the wire from isolation about 1 cm long. Next, we parsing the cartridge and connect the ends of the wire to its terminals.

Then, so as not to damage the light bulb, it is necessary to clean the remaining ends of the wire for a length of 3 cm. Screw the light bulb into the prepared device. After that, turning off the voltage, we clean the ends of the conductor, where you want to find a phase wire.

You do not need to twist the control light contacts with the wire, as you need free access to the conductor's contacts.

Next, using any metal object, we clean the small area on the metal surface of the tap pipe. We supply voltage to the conductor and one contact of the control touch the stripped area on the pipe, and the second one of the wire contacts. When touching the phase conductor, the light lights up.

With potato, check which of the wires phase, is as follows. For the device, two wires of the meter length and a resistor of 1 MΩ will be required. One of the wires must be mounted in potatoes, and attach to the pipe. Another wire is one of the ends mounted in potatoes, and the other is searching for the phase wire. The phase wire will indicate the appearance of darkening on potato.

We understand how to determine the phase and zero (video)

As practice shows, in most cases, the search for phase and zero conductors in the electrical AC power network is not required, since the polarity is not valid when connecting various household devices.

Very often, when performing in an apartment, a house, a garage or in the country of repair or installation work related to electricity, there is a need to find zero and phase. It is necessary for the correct connection of sockets, switches, lighting devices. Most people, even if they do not have special technical education, imagine that there are special indicators for this. We will briefly consider this method, as well as tell you about another device, without any professional electrician. Talk about how to determine the phase and zero multimeter.

The concepts of zero and phase

Before determining the zero phase, it would be nice to remember the smallest of physics and figure out what it is for the concepts and why they are found in the outlet.

All electrical stars (and domestic, and industrial) are divided into two types - with constant and alternating current. I remember from school that the current is the movement of electrons in a certain order. With constant current, electrons move in some one direction. With alternating current, this direction is constantly changing.

We are more interested in a variable network that consists of two parts:

The working phase (as a rule, it is called simply "phase"). It serves the operating voltage.
Empty phase, referred to as "Zero" electricity. It is necessary to create a closed network for connecting and operating electrical appliances, also serves to ground the network.

When we include appliances into a single-phase network, there are no particular importance, where it is the empty or working phase. But when I mount the electrical wiring in the apartment and connect it to the shared house network, it is necessary to know.

The difference between zero and phase on video:

Simplest ways

There are several ways to find a phase and zero. Consider them in brief.

In color vehicle lived

The simplest, but at the same time, and the most unreliable way, is the determination of the phase and zero on the colors of the insulating shells of the conductors. As a rule, the phase vein has a black, brown, gray or white color execution, and zero make blue or blue. In order for you to know, there are also green or yellow-green residential veins, so the protective grounding conductors are denoted.

In this case, no devices needed, looked at the color of the wire and determined - the phase is or zero.

But why is this method the most unreliable? But there is no guarantee that during the installation of electricians observed the color marking lived and did not confuse anything.

Wiring color marking on the following video:

Indicator scolder

The more truthful method is the use of indicator pumping. It consists of a non-conductive housing and a resistor built into it with an indicator, which is an ordinary neon light bulb.

For example, when the switch is connected, the main thing is not to confuse zero with a phase, since this switching device works only on the phase break. The test indicator is as follows:

Disconnect the overall introductory machine to the apartment.
Clean the conducted veins from the insulating layer for 1 cm with a knife. Distribute them to a safe distance to completely eliminate the possibility of contacting.
Submit voltage by turning on the introductory machine.
Shutter sting to bare wiring. If the indicator window lights up, it means that the wire corresponds to the phase. The absence of glow suggests that the found wire is zero.
You need to make a marker or a piece of tape by a marker or a piece of tape, after which turn off the overall automatic and connect the switching machine.

More complex and accurate checks are performed using a multimeter.

Search phase indicator screwdriver and multimeter on video:

Multimeter. What is this device?

Multimeter (electricians are also called the tester) is a combined device for electrical measurements, which combined a variety of functions, the main of which is a mesmer, ammeter, voltmeter.

These devices are different:

analog;
digital;
portable lights for some basic measurements;
complex stationary with a large number of opportunities.

With the help of a multimeter, you can not only determine the land, zero or phase, but also measure the circuit section, voltage, resistance, check the electrical circuit for integrity.

The device is a display (or screen) and a switch that can be installed in different positions (there are eight sectors around it). At the very top (in the center) there is a "OFF" sector when the switch is set to this position, it means that the device is turned off. To perform voltage measurements, you will need to set the switch to the "ACV" sector (for alternating voltage) and "DCV" (for constant voltage).

The multimeter kit includes two more measuring probe - black and red. Black dipstick is connected to the lower socket with the marking "Som", such a connection is constant and used when conducting any measurements. Red probe, depending on measurements is inserted into the middle or upper socket.

How to use the device?

Above, we looked at how to find a phase wire with an indicator pumping wire, but it will not work with such a tool to distinguish zero and land. Then let's get together how to check the veins by a multimeter.

The preparatory stage looks exactly the same as to work with the indicator scolding. When the voltage is disconnected, the ends lived and be sure to distribute them so as not to provoke a random touch and the occurrence of short circuit. Submit voltage, now all further work will be with a multimeter:

Select the measuring limit of the AC voltage on the device above 220 V. As a rule, there is a mark with the value of 750 V in "ACV" mode, set the switch to this position.
The device has three sockets where the measuring probes are inserted. We will find among them the one that is indicated by the letter "V" (that is, to measure the voltage). Insert the probe into it.

Touch the probe to the stripped veins and look at the instrument screen. If you see a small voltage value (up to 20 V), it means that you touch the phase wire. In the case when there is no testimony on the screen, you found a zero multimeter.

To determine the "Earth", clean the small area on any metallic home communications element (it can be tap or heating pipes, batteries).

In this case, we will involve two sockets "Som" and "V", insert the measuring probes in them. Install the device in the "ACV" mode, to 200 V.

We have three wires, among them you need to find the phase, zero and land. One dipstick tap the stripped place on the pipe or the battery, the second touch the conductor. If the screen is displayed on the screen of about 150-220 B, it means that you found a phase wire. For zero wire, with similar measurements, the reading ranges in the range of 5-10 V, when touched to the "Earth", nothing will be displayed on the screen.

Note each living marker or tape, and to make sure the correctness of the measurements are correct, do now measure the measurements relative to each other.

Touch in two papers to phase and zero conductors, the figure should appear on the screen within 220 V. Phase from the earth will give a slightly smaller reading. And if you touch zero and earth, then the screen will be a value from 1 to 10 V.

Multiple rules for the use of multimeter

Before determining the phase and zero multimeter, read the multiple rules that must be followed when working with the instrument:

Never use a multimeter in a wet environment.
Do not use defective measuring probes.
At the time of measurements, do not change the measuring limits and do not rearrange the position of the switch.
Do not measure the parameters whose value is higher than the upper measuring limit of the device.

How to measure the voltage by a multimeter - on the following video:

Pay attention to an important nuance in the use of the multimeter. The swivel switch initially always needs to be installed to the maximum position to avoid damage to the electronic device. And already in the future, if the readings are lower, the switch is rearranged to low marks to obtain the most accurate measurements.

Repair and installation of household wiring with your own hands require the ability to competently determine the potentials of voltage, distinguish the zero phase and the ground inside the home electrical circuit.

For long-term practice, the electrician met a lot of mistakes that admit newcomers. Posted this article so that you do not repeat them. I share the experience as a multimeter to find a phase safely and quickly.

Information broke into several parts, focusing initial attention on features and measuring instrument. The experienced electricians can immediately go to the third section.

What is phase, zero and earth: a brief explanation of simple words

Before you begin to deal with the wires in the apartment, it is necessary to represent well, from where and which methods there are voltage potentials appear than the differences in the grounding methods.

Modern industrial generators produce a three-phase current system.

Voltage on wires or cables enters the consumer from transformer substations.

At the same time, 220 volts, determined between the potentials of one of the phases and the total zero, usually start in the apartment of a multi-storey house. A full-fledged three-phase food can also come to enter a private house.

During the USSR, a two-wire power circuit was used inside residential premises to save materials, when two potential was served on the electrical outlet of the apartment:

one of the three phases;
general zero, which is a grounding of one output of the transformer substation winding and is indicated by Latin letters Pen.

This simplest grounding system no longer has any additional contours.

The modern connection scheme of residential premises is more complicated. It contains the potentials of grounding the output winding of the transformer substation with two highways separating Pen:

working zero N, which is used only for the flow of currents that ensure the useful operation of household mechanisms;
a protective conductor PE designed to remove hazardous leakage currents in emergency situations on electrical equipment.

The varieties of the modern grounding system with an additional protective contour are its modifications: TN-C-S, TT.

Now the residents of private houses have the opportunity and escape from accidental emergencies.

The same people who live in old apartment buildings have to wait for the line when the state translates them to a safer system. And new buildings are based on existing PUE standards.

Thus, in a modern apartment you can find two systems for connecting household appliances made using a two-wire or three-wire scheme.

For them, their two types of electrical outlets are produced, which are mounted 2 or 3 wires.

To connect them are designed.

Thus, the potentials of the working zero N and the land of re are combined on the grounded part of the transformer substation output winding. In the old scheme, they are summed by one conductor Pen, and in a new one - twin.

The requirements of the PUE to the installation of the RE conductor are very tough, it should provide a minimum allowable resistance to emergency current flow. It is mounted without using switching apparatuses on high reliability wires.

Contacts of automatic and differential switches, Uzo, switching devices, and working wires are selected to transmit only conventional loads.

At the expense of these two requirements, and due to the removal of household wiring from the transformer substation on the consumer side between re and n, a small potential difference is created, which can be measured by an ordinary voltmeter.

Why a multimeter must be translated into a voltmeter mode when checking the phase

Prior to the mass appearance on sale of digital devices, our friends and acquaintances were often brought to the repair of burnt analog testers to repair.

The reason for their damage was almost always alone: \u200b\u200bincorrect selection of the measurement mode when the device is connected to the voltage circuits.

At the same time, at best, the chains of connecting resistors with buttons and switches were fused, and at worst - the high-test measuring head with conductive springs. Recent faults most often did not repairs.

People simply did not understand that the tester, like the digital multimeter,

The only difference is that the tester works with analog values, and the multimeter is digitized. But the principles of connecting both types of devices are the same, reduced to two simple rules:

when measuring the voltage, the switches set to the position that enters the calibrated resistance, which limits the current through the current-measuring head or the sensor;
the unknown voltage values \u200b\u200bshould always be performed on the maximum value of the instrument scale.

The incorrect position of the switches that translated the device into an ohmmeter mode or ammeter is most often found in beginners by inattentive and due to low skills.

In my memory there is a case when two experienced electrics, hoping in a hurry on each other, burned the expensive exemplary voltmeter - the standard of the accuracy class 0.2.

The device had to urgently use to exhibit the settings of the battery pack of the operational current of 220 volts at a 330 kV substation.

One worker held the device in his hands horizontally and filed ends with the second to the measurement of the measurement. None of them paid attention that the switch stood at the lowest measurement limit. As a result of the flow of increased current, the measuring head burned out completely.

This case is not typical, but clearly shows that electricity does not forgive any errors. The current flows to where it turns out to be less resistance.

Incorrectly connecting a multimeter or tester to voltage circuits In addition to damage to the measuring instrument itself, creates a short circuit mode, harmful to household consumers and wiring.

Therefore, before installing the measuring probe on the voltage circuit, it is necessary to check the initial position of the instrument switches to the voltmeter mode.

Actually, it is worth noting that elite digital multimeters are equipped with a built-in electronic circuit, protecting the device from incorrect connection to voltage circuits, and in budget models it is missing.

Its in the people are often called "fool protection." In many cases, it can save the device and domestic network, but I still do not recommend using these opportunities, I do not recommend: plug the voltmeter always correctly.

Technical techniques in pictures: as a multimeter to look for voltage potentials in electrical wiring

Now manufacturers produce a very large range of digital measuring instruments. They have different controls, appearance, configuration. Therefore, it is impossible to show the position of the buttons and the switches for all models.

In it, I drew and show a generalized model with the maximum location of the control buttons and switches, where in detail in tabular form I explain the position of each organ. Read and use.

For permanent use, the budget pocket multimeter MESTEK MT102 has chosen with a large number of functions and made

This device will be used when demonstrating work techniques to determine the difference in potentials between wires and contacts.

At first, I show how to use it to measure the voltage in the outlet. In this example, we immediately solve two tasks:

We determine the technical function of the multimeter itself and its ends to connect.
Control the presence of 220 volts in the apartment.

Ends for a multimeter - special wires with tips for connecting the device with a measured circuit made in red and black.

For this color, they should always be inserted into the corresponding sockets of the lower block. Moreover, the red end is usually connected to the right.

If there are additional red nests on the device, then they are used only to measure high currents or at the limit of milli-, microamper.

The central switch, I transferred my MESTEK MT102 to the voltmeter measurement mode by selecting the "V" position, and by using the "SEL" button to measure the variable-current parameters "AU".

Only after that the ends connected to the device installed in the outlet to measure the voltage.

The display appeared the value of 242.8 volts, which is stacked in the norm.

After that, we can conclude that there is a voltage in the outlet, and MESTEK MT102 and its ends are good and they can be used further. Preparatory procedures are completed, but further work beginner electrician can ease knowledge of the colors of cables.

Rules of color marking of wires: how to consider them

The colors lived greatly simplifies the installation of electrical wiring and the search for malfunctions. Therefore, manufacturers are applied to isolation, and professional electricians try to adhere to the editing rules.

Color marking rules imply the designation:

protective RE conducting yellow-green color;
working zero blue or blue;
phases are the rest: white, orange, brown, black, gray, red, purple.

Please note that the cable is not always and the wire has a similar variety of colors. Isolation lived often can have some one shade. Yes, and not all installers, and especially homemade masters adhere to this rule.

Color marking is designed to facilitate troubleshooting and mounting work, it is an additional way to determine the phase and the working zero. But it is impossible to rely on this method.

By the way, during work more than once had to observe how in a rush to eliminate faults, even on the responsible secondary chains of 330 kV equipment on the substation, experienced electricians had to be replaced and laying wires from those on hand, not paying attention to their coloring.

What disgrace is done in the household home network allowed by the untrained personnel, you can imagine themselves.

Phase search sequence Voltmeter: Step-by-step instructions from 3 standard cases

The work consists of the preparatory and main part.

At the initial stage, check the condition of the measuring device and its ends, as I showed above. In many cases, this short procedure saves further working hours. Make it with a habit, because there is a bad contact in the nest, the breakdown lived, the served nutrition batteries, any other defects will deliver a lot of trouble.

Option number 1. Three-solid household power scheme

Determination of the presence of phase potential on the wire will be shown on the example of wiring with the veins of one-photographic isolation. They assume the presence of a phase, land and zero. We will define them.

Step number 1. Pariable stress measurements between wires

Arbitrarily labeled all three wires. For example, we assign them the numbers, letters or at the top down either from left to right.

At the same time, I remember that they are under voltage and you can only touch them in compliance with the safety rules without creating a body contact with current-friendly veins.

For clarity, I placed them vertically and assigned the number 1 ÷ 3. Then the collapse of the voltmeter can consistently measure the potential difference between current-time cores.

Suppose we saw 220 volts between wires 1 and 2, as well as 2 and 3.

And between the veins number 1 and 3, the voltmeter shows the shares of the Volta, close to zero.

Step number 2. Analysis of measurement results

Based on these measurements, it can be concluded that the total wire No. 2 for two cases of measuring 220 volts is phase.

Option number 2. Two-wire household network

We have two wires with a phase and zero, but do not know where what potential is.

Step number 1. Stress measurement between wires

Initially, check the potential difference between current-time cores. With a good chain, we must see 220 volts, as I showed the socket on the photo above when checking the device's help.

Step number 2. Stress measurements between each wire and the contour of the Earth

One end from the voltmeter is a crocodile connecting to a water tap, the heating battery or any other grounded metal structure. The second probe alternately concern the current-carrying livers.

In one position, the voltmeter will show something close to me, and in the other - 220 volts. There will be a phase potential on this wire.

Both cases of voltage checks for the two- and three-wire circuit are well suited to estimate the presence of a phase in the corresponding types of sockets.

Option number 3. The principle of determining the phase on capacitive current

Here is the same technology as when checking the voltage with a regular indicator screwdriver.

Inside the indicator, there is a high-resistance resistor that limits the current through the body of the operator to the ground to a safe value: several milli-or microampers sufficient for the luminescence of the neon or LED light bulb.

When a person touches the fingers of the contact on the end of the screwdriver, then if there is a phase potential at the opposite end of the blade, a capacitive current is created and the light is created. Otherwise, its glow will not.

Capacitive current flow scheme is as follows.

When replacing the indicator by a multimeter in this method, it is quite possible to find a phase that I also show on the next photo.

One voltmeter probe is installed in the socket of the socket, and the second touch the fingers. On the scoreboard you see the reading of 73 volts. At the same time, I sit in a chair located on a dry wooden floor.

Due to the good body isolation from the contour of the Earth, my Mestek MT102 strongly underestimates the magnitude of the phase potential. Therefore, I do the second experiment.

He took off his sock and touched a bare stop to the painted heating battery radiant. That's what happened.

Mestek MT102 has shown 175 volts, which is closer to the truth.

You can use this method, but you can not believe the digits of the display: they are approximate and depend on the quality of the grounding of the body.

On another contact, you will not see the rosette in this way.

How to distinguish the zero wire from the ground in a three-wire circuit

When we found a phase, then the two remaining serviceable wires will be the potentials of the working zero and re conductor. We need to distinguish them.

To do this, initially use the color label if it is applied correctly. But I definitely recommend performing electrical measurements for accuracy.

It is necessary to just once again carefully measure the magnitude of the potential difference between the phase and these two wires. The earth will be the wire where the reading of the multimeter is a little more. There are smaller voltage loss due to high demands on the installation and lack of switching apparatuses inside the chain.

The third remaining wire is a working zero. For practice, you can measure the potential difference between the Earth and zero, compare it with the honors of measurements between these wires with the phase.

Small deviations will be caused:

the class of accuracy of the device;
the quality of connection of the ends;
difference of arithmetic actions from the methods of vector algebra.

Here I will share three cases that should help you relieve life when communicating with electricity, eliminate typical errors.

Working the tester on different objects I had to make a simple extension cord of his ends.

On the homemade plastic Motovil wound a long flexible wire and soldered two plugs to him. The photo shows a crocodile and homemade probe from a bicycle knitting, closed with a ballpoint pen. They are easy to wear and removed depending on the necessary tasks.

This extensioner takes up little space, not confused, very reversing me when the remote objects are called. It will also be useful when checking the phase by the capacitive current.

"Faulty TV"

This case occurred when we still worked black and white kinescopic TVs.

A neighbor from the fifth floor came with a request: "Help, I stopped turning on with me." I had to take the tester and tools. The first thing measured the voltage in the outlet: 220 volts, the norm.

Once again I checked the outlet: again 220. I had to think greatly. As a result, I took the extension cord, I connected it in another room and the TV was connected. He earned.

Began to disassemble the outlet. Aluminum noodles 2.5 square. Both ends are good, the tester shows the voltage 220. Included the table lamp, and it does not burn. I come back to the voltmeter and see only 40 volts.

I conclude: Contact disappears somewhere in the load. I climb into a junction box, inspecting the connections. Tearing the wires and notice insulating the broken custody: the ends are movable, but in contact.

When a small current from the tester passes through them, the contact is reliable, and with an increase in the load from the wall lamp or the TV, it worsens and the chain does not work.

Previously, such faults were well detected by the control lamp. Now it is prohibited by the rules for a number of reasons. However, check the presence of a phase on the wire under load is more correct than without it.

"Electric part-time"

A dozen years ago arose about the repair of a bathroom and toilet. Wife recommended a good tile named Sergey. He is professionally engaged in finishing work, has experience, shows photos in his portfolio.

The price arranged, agreed. Sergey has begun work. In the course of the matter, he took on all repairs, as they say now, "turnkey rooms", including plumbing, electrician, replacement of doors.

During the non-successful dismantling of the old door frame, a small part of the wall with stamped wiring was collapsed. Some wires broke off, and on other hung a piece of concrete. (In this place, a three-key switch was installed and a filling unit.)

Sergey tried to disassemble the formed ball and received a strong blow to the current. The machines turned off a short circuit, and the unsuccessful electrician fell into a shock state.

I came to his happiness at this point from work and saw all this picture. Sergey immediately stated that he would not cope with this malfunction himself, and he would now stay away from electricity.

I had to take for a transvelon and the installation of all wiring. I also want to remind you that work under tension belongs to dangerous. They are allowed to perform only trained personnel with:

special knowledge;
practical skills;
strong physical health.

If at least one of these requirements is missing, then the trouble is inevitable. So that it was not - attract professional electricians. That's all information on how to find a phase multimeter. You can complement it in the comments or ask additional questions. I'll answer.

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Carrying out repair work in any room, an important point is to equip this room with electricity. In addition to the wiring, you should not forget about the need to install sockets and switches, with which lighting control will occur. Here, a fairly important point will be the determination of the phase, zero and grounding conductor of the system.

For professional installers, this task is very simple, which you can not say about ordinary alone, which can not always cope with such a task. However, the search for zero and phase is not so complicated as difficult, as it may seem initially, it includes several methods for determining.

It should be understood that the wiring in the apartment usually has a voltage of 220V, since it involves connecting to zero conductor and to one of the phases. In this case, grounding is mandatory, which makes the electrification of the room safe for the inhabitants.

What is a phase and zero in electricity for a beginner

Phase designation and zero letters. In addition to color designations, the locked wire marking is possible. The phase is usually denoted by the Latin letter "L" and the zero wire is made to marked with the letter "N". In addition, the grounding has a grounding, denoting which is accepted by the letter "G".

How to determine the phase and zero indicator screwdriver

How to find out where the phase and where zero in the outlet indicator probe video

Determination of phase and zero multimeter

In addition to the use of an indicator screwdriver, it is possible to use a multimeter, which will also allow you to determine the conductive wires on the network. The prerequisite for its use is the preliminary stripping of the wires.

The main rule when using a multimeter is a ban on the simultaneous touch of the phase wire and the grounding circuit. Such negligence can lead to a short circuit and, as a result, to traumatic burns.

How to find a phase and zero without instruments

Phase definition without indicator and video device

An alternative incandescent bulb can be neon light bulb, which will find the polarity of the system.

In conclusion, it should be noted that the answer to the question "how to determine the phase and zero" has several solutions. Namely: indicator screwdriver, multimeter, and can also be without appliances. It all depends on the possibilities and availability of devices at hand. Mandatory is the observance of all security measures when working with electricity.