Junction box installation. Connecting wires in a junction box: learning how to connect wires. The sequence of actions for installing and connecting the junction box

Probably, many people are familiar with the situation when, when touching metal products in the bathroom, a slight tingling of electric current is felt - many people try to ignore such a nuisance. However, this is not to be trifled with. In a certain situation, such light tingling of an electric current can turn into a strong discharge that can kill a person. In this article, together with the site site, we will deal with the question of how the bath is grounded and why should it be done at all?

How to ground a bath

Grounding the bath: why do it

With the fact that the lack of grounding can become a source of quite serious troubles, to say the least, we figured out, now let's take a closer look at the purpose of the ground loop in rooms with a humid environment. If we formulate the answer to this question briefly, then the protective grounding of the bath is intended not only for its safe operation, but also for equalizing the electrical potential of all conductive surfaces. In general, if we talk about grounding, then we need to consider it comprehensively, together with all current-conducting products available in the bathroom. Only in this case, connecting the bath to the ground loop will make sense.

Surely now many people have a question, what to connect the bath to? Where can I get a ground loop? After all, we have long cut off the old steel ones and their new, plastic ones. This is not to say that you got excited, but grounding the bathtub on water pipes is not the only correct solution. It’s just that in such a situation, you will additionally have to lay one single wire from the shield to the bathroom, to which all conductive objects are connected. But more on that later, but for now let's deal with the question of how to ground the bath and what materials will be needed for this?

Why do you need to ground the bath

How to ground a bath: materials used

If the question of how to ground the bathtub had been asked to me 20 years ago, then, undoubtedly, the answer to it would have been “steel cable” or “six wire”. Now times have changed, and this issue is being resolved more culturally - a copper twisted ground wire is used for the bath, which is connected with no less cultural crimps and terminals.

How to ground a bath with your own hands photo

Not every wire is suitable for grounding the bath - according to the requirements, its cross section should not be less than 6 square millimeters. Exactly the same cable will need to be laid from the electrical panel, or rather from its central ground terminal. To connect the central grounding conductor and wires coming from other metal objects, as a rule, a special steel bus with screw clamps is used. If we talk about the folk method, then this is a bolt with a nut and washers - each individual wire must be located between two washers. The bolt is clamped with all the force.

You can watch the advice of a bath grounding specialist in the video.

Types of baths and features of their grounding

Now a little more about how to ground the bath, depending on the material of manufacture.

This is how the issue of grounding in the bathroom is solved with almost all metal products - a wire, a hole and a bolt with a left-hand thread. Kidding. Most products, especially powerful electrical consumers, are already equipped with terminals or at least holes for connecting the ground loop.

Jacuzzi bath grounding photo

And in conclusion, a few words about the grounding of the hot tub or, as it is now commonly called, a jacuzzi. The question of how to make grounding in a bathroom equipped with such a plumbing fixture should be decided in the very first place - this is your safety! You should know that you are going to take a bath that is crammed with all sorts of electrical equipment.

The jacuzzi must be grounded with a separate powerful cable, one end of which is connected directly to the plumbing fixture itself, and the other to the grounding input to the house (usually it is located before the switchboard).

That, in principle, is all you need to know about how the bath is grounded. To summarize all of the above, we can distinguish three main points based on which such work is carried out: a powerful copper cable with a cross section of at least 6 squares, reliable contact and connecting the bath directly to the ground loop to the switchboard. And finally, let me remind you about such a product as an RCD - all electrical wiring in the bathroom must be connected through it without fail.

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ASSOCIATION "ROSELECTROMONTAZH" TECHNICAL CIRCULAR No. 23/2009 ON ENSURING ELECTRIC SAFETY AND IMPLEMENTATION OF THE SYSTEM OF ADDITIONAL POTENTIAL EQUALIZATION IN BATHROOM, SHOWER AND SANITARY CABINS electrical safety in installations associated with the likelihood of electric shock from a jet of water, water taps, mixers, heated towel rails and other metal elements of water fittings. In chapters 7.1 and 1.7 of the "Electrical Installation Rules" (PUE) of the 7th ed. the requirements for conductors of potential equalization systems established by GOST R 50571.10-96 (IEC 364-5-54, publication 1980 with changes in 1982) and some requirements of the additional standard IEC 60364-5-548 (publication 1996 with changes in 1998). To date, a new edition of IEC 60364-5-54 (published in 2002) has been released, which clarifies the requirements for the selection of conductors for the main potential equalization system and the additional potential equalization system. The purpose of this circular is to clarify the implementation of a number of provisions of chapters 7.1 and 1.7 of the EMP, specific recommendations for the implementation of individual elements of the additional potential equalization system in bathrooms, showers and sanitary cabins and bringing them into line with the new international requirements regulated by the IEC 60364-5-54 standard in a 2002 publication, in response to incoming requests. When implementing an additional potential equalization system in bathrooms, showers and sanitary cabins, you must be guided by the following: The additional potential equalization system must include all open conductive parts of the equipment, accessible to the touch of third-party conductive parts, including metal fittings of the floor base, protective sheaths and protective grids of heating cables , outer metal shells of protection class II equipment. Protective contacts of sockets for bathrooms, showers and sanitary cabins are also included in the additional potential equalization system. Note. Tap water of normal quality, according to the value of volumetric electrical resistance (conductivity), refers to semi-conductive substances and, from the point of view of the possibility of electric shock, is not considered as a third-party conductive part. When using metal-plastic pipes for equipping bathrooms, showers and sanitary cabins, depending on the technology for making pipe connections, it is possible to form a continuous conductive circuit formed by pipes and fittings. Conductive elements of the water supply system: taps, faucets, heated towel rails, valves and other parts made of metal, in this case are considered as third-party conductive parts to be included in the additional potential equalization system. To include water fittings in the additional potential equalization system when using metal-plastic pipes, it is recommended to install conductive inserts on the cold and hot water supply pipes and connect them to the additional potential equalization system . In this case, the elements of the plumbing system themselves: taps, faucets, heated towel rails, valves and other parts made of metal, do not need to be separately connected to an additional potential equalization system. A conductive insert is installed in front of the inlet valve on the side of the riser in order to prevent damage to electrical connections during plumbing repairs. In the case of using metal pipes for risers and passing them in the sanitary duct of the corresponding premises, the installation of conductive inserts is not required, it is sufficient to connect the conductors of additional potential equalization directly to the metal pipes of the risers. In buildings where water supply to bathrooms, showers and sanitary cabins is carried out by branches in non-reinforced plastic pipes from the distribution network, conductive elements of the water supply system: taps, mixers, heated towel rails, valves and other parts made of metal are not considered as third-party conductive parts and are not subject to inclusion into the system of additional potential equalization. In this case, the installation of conductive inserts in front of the inlet valve on the side of the riser and their connection to the additional potential equalization system is considered as a recommended measure. This technical solution provides electrical safety in case of inadequate quality of tap water and / or when replacing plastic pipes with metal-plastic pipes during the operation of the building. When performing an additional potential equalization system in the room, the installation of a special potential equalization bus is not necessary. If during the implementation of the project, for structural reasons, it was decided that it was necessary to install it, then it is recommended to place it in a plumbing box or other place convenient for maintenance. When using plastic pipes for draining in multi-apartment residential buildings and public buildings, this part of the sewerage system is not required to be included in the additional potential equalization system. In individual residential buildings, when constructing an autonomous sewerage system, for example, of the backlash-closet type, there is a possibility of the local land potential being carried in from the side of sewerage. To ensure safety in this case, it is necessary to install a special conductive insert in the drain pipe (drain pipe) connected to the potential equalization system, and / or connect the conductive parts of the sewage storage tank to the potential equalization system. In sanitary cabins, to ensure electrical safety, the protective contacts of sockets installed outside on sanitary cabins should be connected to an additional potential equalization system, and the lamp in the toilet of a separate bathroom should be of protection class II, as in zone 2 of the bathroom. In buildings where water supply is carried out by branches from an external distribution network (main), which is typical for most individual residential buildings, the latter should be considered as local land. In case of damage in external power supply networks, made in accordance with the requirements of the PUE of the 7th edition, on the protective PE (PEN) conductor of the installation relative to the local ground, a voltage of up to 50 V may appear, and in case of damage (breakage) of the PEN conductor of the supply line - up to values close to the phase voltage. When performing water supply in pipes made of insulating materials, in order to ensure the effective operation of the main potential equalization system, regardless of the quality of the water supplied, it is necessary to provide electrical connection of water with the potential equalization system directly at the water supply inlet to the building. The cross section of the conductors of the additional potential equalization system connecting the PE busbar of the shield with third-party conductive parts must be at least half of the calculated cross section of the PE busbar of the shield. If there is electrical equipment in the room connected by a protective conductor to the PE bus of the shield and included in the system of additional potential equalization, it is not required to connect the PE bus of the shield to third-party conductive parts with a separate conductor (see clause 7.1.88 of the PUE). The cross section of conductors connecting open conductive parts of electrical equipment and / or protective contacts of sockets with third-party conductive parts must be at least half the cross section of the PE conductor of the corresponding equipment power line. The cross section of the conductors connecting the open conductive parts of the electrical equipment must be at least the minimum of the PE cross sections of the conductors of the power lines of the connected equipment. The resistance of additional potential equalization conductors connecting any two third-party and / or open conductive parts accessible to simultaneous contact should not exceed that calculated by the formula: R \u003d 12 / Ia, where 12 is the safe voltage level adopted for zone 0 of bathrooms and showers, V ; Ia is the value of the current that ensures the operation of the overcurrent protection in a time of not more than 5 s in the TN system (in the absence of data, the cut-off current is taken), or the rated differential breaking current of the input device for the differential protection device in the TT system. Note. The use of the TT system is allowed, in accordance with the provisions of clause 1.7.59 of the PUE, in limited cases, in particular when connecting an individual residential building to an overhead line up to 1 kV, made with bare wires. According to the conditions of mechanical protection, the cross section of copper conductors of the additional potential equalization system must be at least: 2.5 mm2 - in the presence of mechanical protection; 4.0 mm2 - in the absence of mechanical protection. It is allowed to use steel conductors with a cross section of at least 16 mm2. Connections of the conductive parts of the additional potential equalization system can be made: according to the radial circuit, according to the main circuit using branches, according to the main circuit without branches (connection to a common inextricable conductor) and according to the mixed circuit. In individual residential buildings and other low-rise buildings, in the presence of a single input-distribution device (shield), the additional potential equalization system is combined with the main potential equalization system.

Reading time ≈ 4 minutes

One of the important steps in the installation of electrical wiring is the connection of wires in the electrical junction box, which follows immediately after laying the cable. At first glance, it may seem to some that using a junction box for wiring is essentially a waste of time, but this assumption is wrong for several reasons.

Wiring diagram in the junction box

During the operation of the wiring, malfunctions may occur - for example, an open circuit has occurred. If, during the electrical installation, the workers did without a junction box, and the joints were simply rolled up with a finishing material such as plaster, then in order to get to the connections again, you will have to break the exterior finish - tear off the wallpaper, break the layer of plaster, etc. It is unlikely that anyone will be satisfied with such prospects. If in the future you need to install additional sockets, then in such cases it is not always convenient to run wires from sockets already installed earlier, it is easier to connect directly to the box.

If the wires are connected using terminal blocks, then a channel of a sufficiently large depth will have to be punched in the wall, which is much more labor-intensive than simply connecting the wires in the junction box.

Finally, from a fire safety point of view, the advantage of using junction boxes is undeniable. For the proper organization of electrical work, there are special Rules for the Construction of Electrical Installations (PUE), which also regulate the procedure for connecting electrical wires.

Methods for connecting wires in a junction box

According to these rules (PUE), there are the following ways to connect wires in a junction box:

• Connection using terminal blocks is the most preferred way: the terminal blocks are small and easily fit into the junction box, and it is not difficult to buy them. It remains only to cut the wires to a certain length, connect the corresponding cores and put the resulting assembly in a box.
• Connection of wires in the junction box by soldering- a method more suitable for professionals who have sufficient experience in carrying out such a procedure. Without experience, a person will spend a lot of time on soldering, and it’s not a fact that the result will be a high-quality connection.
• Connection of wires in the junction box crimping method can be considered the most reliable one-piece connection. However, this is a rather time-consuming job that requires skills, the availability of special tools and materials - these are press tongs, copper or aluminum sleeves and heat shrink tubing. The pre-stripped conductors should be inserted at both ends of the sleeve until it stops and the connection is crimped. Immediately before crimping, one of the switched wires should be put on a heat-shrinkable tube, and after crimping, slide the tube onto the sleeve and heat it to the shrinkage temperature.

The twist method is the simplest connection option. However, if we talk about whether such a connection of wires in a junction box is reliable, the PUE allow such a method only as a temporary one and prohibit twisting without subsequent full completion of the connection.

For those who are faced with such a task as connecting wires in a junction box for the first time, the photos and videos presented in the article will help to visualize as clearly as possible how this procedure is carried out in all the ways listed above.

The main wiring elements switched in the box are lamps and sockets, while the wire connection scheme in the junction box will be different for them. The socket will require a simple connection of wires by color. There will be three colors in total: phase (gray, brown or black), zero (blue or cyan), ground (yellow with a green stripe). There are also wires without grounding, then the cable will be two-core, and instead of three colors there will be two. For a luminaire with a single-gang switch, only 2 wires will need to be connected in the box: zero will be connected to the wire going directly to the luminaire, and the phase will pass to the luminaire through the switch. For a chandelier with a 2-key switch, the only difference will be that in this case, 2 wires will go to the chandelier from the switch, which are responsible for different groups of light bulbs, and zero will remain common.

Video of connecting wires in a junction box

The junction box is of great importance in the electrical circuit.

It distributes wires for further consumption of electricity.

If you decide to do your own wiring, then first understand all the intricacies.

To better understand this process, we will consider it in stages. And also let's talk about the types of wire connections and the features of opening the box.

Types of wire connections

Several types of wire connections are used. Choose the option that suits your case best.

Twisting

Now this method of connection is prohibited by safety regulations due to unreliability.

If you decide to choose this connection option, you should understand the possible consequences.

Twisting is very simple: peel 1 cm of insulation from the wires, and then carefully wind them on top of each other. The number of turns depends on the diameter (the thicker, the fewer turns).

Crimping

This method is used very often. It is produced using a special sleeve corresponding to the bundle of wires in diameter.

The sleeve material must match the cable material.

The process is carried out using press tongs in the following sequence:

1. Remove the insulating layer from the wires along a length equal to the sleeve.
2. Twist them in a bundle and insert them into the sleeve
3. Press the sleeve with wires with press tongs.
4. Insulate the connection with available insulating material.

Welding

After welding, a whole wire is obtained that will not oxidize, unlike other connection methods.

Welding requires the following equipment:

• welding machine for 24 V with a power of 1 kW,
• flux,
• electrodes,
• protective equipment (mask, gloves).

It is performed as follows:

1. Remove the insulation and sand them to a shine with sandpaper.
2. Connect the wires with a twist.
3. Pour the flux into the recess of the electrode.
4. Turn on the welding machine, press the electrode against them and hold until a lump forms - “contact points”.
5. Clean the point of contact from the flux and varnish it, and then insulate it.

Spike

It is carried out in the same way as welding. Only the connection is made using solder heated with a soldering iron.

It is important that the solder penetrates into the twist. This method should not be used in places of strong heating of the cable and in places of mechanical stress.

This method is simple, fast and inexpensive. In this way, you can connect both the same wires, and different in composition.

The connection is simple: first, about 0.5 cm of insulation is peeled off, and then they are inserted into the clamp and tightened with a screw.

Bolted connection

Such a connection is quite reliable, but very voluminous.

Therefore, it is mainly used in boxes of old models, since it simply does not fit in modern compact boxes.

The order of work is as follows:

1) Place a steel washer on the bolt.

2) Put one of the wires on the bolt, stripped of insulation and twisted into a ring. Do the same with the second one.

3) Put on the next washer.

4) Put on the ring of the second wire.

5) Put on the last washer and tighten everything with a nut. Insulate the entire connection (although insulation will only add volume to it).

Connection with self-clamps

The most modern type of connections, easy to use.

Among other things, there is a paste inside the clamps that prevents metal oxidation, which means that different conductors can be connected without problems.

The connection is made in the following sequence:

1. Remove about 1 cm of insulation from the wires.
2. Lift up the clamp lever.
3. Insert the wires into the connector.
4. Push the lever down (if there are no levers, just click the clip)

For safety, reliability and correctness of connections, it is necessary to know the features of wire designation.

Wires marked "zero" (blue) and ground (yellow) are connected according to color (see diagram). If you are installing a two-wire system, then the circuit is the same, except for the ground wires.

The phase desoldering process (black or red) is much more difficult. If you plan to run only the wire through the box to connect the outlet, then connect their phases together.

If material goes out of the box to one-button switches, then it must be twisted for the switch with all phase wires. Connect it, departing from the switch, to the phase wire going to the lighting fixture.

You should end up with four connections.

When using two-button switches in a three-wire system, a four-wire wire must be used for the chandelier.

In the case of two-wire wiring, a three-wire cable is used, since ground is excluded from the circuit.

Apart from a separate ground twist, there should be four connections in the box. Wires marked "zero" (blue) are connected to each other. The phases of the sockets are connected to the power cable and connected to the common terminal of the switch with two keys.

Two wires should go from the switch to the lighting fixture.

From the foregoing, it follows that desoldering the box is a very simple process. It is enough to understand the designation and the order of their connection.

The sequence of actions for installing and connecting the junction box

To get started, prepare everything you need for electrical work:

• cables 3*2.5, VVG,
• cables 2*2.5, AVVG,
• double switch,
• mounts,
• lighting fixture,
• socket,
• pliers,
• roulette,
• wire cutters,
• pliers,
• flat screwdriver,
• a hammer.

2) Marking. Mark the places for installing electrical appliances and the places where the wires pass.

3) Installation. First, turn off the power supply.

Route the wires to the junction box (it is better to lay the cable in pre-prepared stubs). Secure wires with small nails or plastic staples.

In wooden houses, special mounting boxes are usually used.

4) Connecting electrical appliances and connecting wires.

Lead about 10 cm of cable into the pre-installed junction box. Remove the overall sheath from the wires and about half a centimeter of insulation from each core.

Connect them with terminal blocks. In this case, a two-wire wire is used (one core is zero, the second is phase).

Connect the socket and lighting device to the neutral cable. Connect the wire with the phase to the socket and one wire of the switch cable. Take the second wire of the switch cable and connect to the first button, and the third to the second.

5) Check system operation. Turn on the power supply and check the operation of the socket and switch.

Everything should work properly. Process completed.

Now you know how to connect the wires in the junction box and how to connect electrical appliances. Using this knowledge, you can easily cope with the installation of electrical appliances.

Video: 3 best ways to connect

In order to provide every corner of an apartment or office with electricity, you cannot do without a junction box. Modern junction boxes are very diverse both in shape and in the materials from which they are made. They are surface mounted and internal.

The purpose of such devices is to route the wires in the right direction to the points of consumption or disconnection - these can be switches, sockets or lighting fixtures. It will not be a hassle for a professional electrician to separate the wires in a junction box, but for a novice electrician it can turn out to be a real science. Today, WAGO universal terminals are increasingly used for contact connections in the junction box.

We observe the colors of the wires in the junction box

In order to cope with the installation, you need to connect your imagination: wires are “pipes”, and electric current is “water”. There is a “water supply” through the phase wires, but a “return” flows through the neutral conductor, while the protective conductor serves just in case of an emergency: if “water” leaks somewhere, it will certainly be “drained” into the ground. It is very convenient that they are modern. The most common color looks like this: white - phase (L), blue - zero (N), yellow-green - ground (PE).

During wiring, it is very important to follow the sequence in the colors of the wires, which will greatly facilitate their breeding in the junction box. Before proceeding with electrical work, you need to clearly determine the installation of lighting points, sockets and switches, i.e. draw up a diagram to install junction boxes in convenient places, and in the future, preventive and repair work can be carried out.

Be sure to read detailed articles about wiring:

Junction box installation procedure

Many make repairs using stretch or suspended ceilings, so the wiring must be laid so that it does not end up in the drilling area when the guides are mounted, and care must also be taken to ensure that the junction boxes remain in the access area. If the junction box is left behind a false ceiling, a small hatch can be installed.

The last word of electrical engineering says this: from the switchboard you need to lay a wire for lighting - 3x1.5, for sockets - 3x2.5 wire. Therefore, in the junction box there may be a sufficiently large number of wires for connection. In order not to get confused, they must be labeled.

Scheme in the junction box, two lamps

Scheme in the junction box, two lamps and a group of sockets