Categories: Electrician at home, Sockets and switches, Electric installation work
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How to properly transfer the socket and switch

How to properly transfer the socket and switch The need to transfer sockets and switches, as a rule, arises after moving furniture in the apartment, or when wiring is brought to the so-called European standard, according to which sockets are installed at a height of 20 - 30 centimeters, and switches at a height of 90 - 120 centimeters from the floor.

If need to lower the outlet, and the wiring is made in a coupler, it is enough to install a new installation box in the required place and shorten the cable to the desired length. The situation is more complicated when required build up cable. Two tasks immediately arise here. How to connect cable cores so that the connection is high-quality and durable, and what to do with the old installation box.

The worst solution to this issue is to connect the cable, for example, twisting the wires, insulate twisting, cover up the wires with alabaster in the old installation box and forget where this time bomb is located.

According to existing rules, all cable conductor connections must be accessible for inspection. But this rule is far from always fulfilled, and finding terminal boxes is often a daunting task. When upgrading the electrical network, it is always advisable to plot the cable paths and the exact bindings of the terminal boxes.

The wiring should last at least 20 years. And where is the guarantee that done wire connection will last all these years.

The most reliable connection of copper conductors is welding and crimping. These methods require special tools and skills, but may well be replaced by simpler solutions.

For connecting the cores of the cables of the lighting network, the current in which rarely exceeds 2 - 3 Amperes, it is quite suitable Wago Flat Spring Terminal Blocks. Shown in fig. 1 222 series terminal blocks allow you to quickly connect and disconnect wires. In my personal experience, over two years of operation of the terminal blocks of this series at currents of 4 - 5 Amps of two thousand terminal blocks burned out only one.

Fig. 1. Terminal block Wago (type 222)

For an outlet network, it is preferable to use time-tested types of wire connections. In fig. 2 shown twisting two wires. For its implementation on both wires, insulation is removed on a plot of about 25 - 30 millimeters. The cores must be stripped with a fine emery cloth. It is very important not to pull the twist so that the conductors do not break.

Fig. 2. Twisting of cable veins

In fig. Figure 3 shows a close-up. After twisting the wires, the twist is soldered with lead - tin solder. For soldering, it is advisable to use rosin. Acid fluxes should not be used. It remains to carefully insulate the joints and lay the wires in the box.

Fig. 3. Close-up twisting

A well-made twist can last several decades without any soldering. In it, the cores are crushed into each other, forming a very reliable contact with a large area of contact. But, the quality of the twist to a large extent depends on the qualifications of an electrician. Therefore, at present, the connection of wires by the method of twisting by the inspectors of the Energy Supervision is not welcome.

The situation is more complicated when it is necessary to connect a copper wire with aluminum. They should never be twisted together. The most affordable at home connection of a copper wire with aluminum is to bend both conductors with a ring and tighten with a bolt connection through a steel galvanized washer.

In a bolted connection, you must use a good engraving washer and lock the connection with a second nut.The second nut will prevent self-unwinding of the connection, the engraver compensates for the shrinkage of the aluminum wire. The fact is that aluminum in the “compressed” state has the property to shrink, as a result of which the contact transition resistance increases.

Now consider the second part of the problem - what to do with the old installation box. If the former place of the outlet is covered with furniture, then the installation box can simply be closed with a lid, laying the connected insulated wires in it. If this place is in sight, then the old installation box will have to be closed and this place puttied. In fig. Figure 4 shows a section of a wall with a mounting box for a socket, which will now act as a terminal box.

Fig. 4. Section of the wall with the installation box

It is highly undesirable that the junction of the cable cores come into contact with cement mortars and various putties. To allow this, fairly sophisticated isolation methods must be used. with heat shrink tubing. Easier to cut, as shown in fig. 4 circle of drywall and paste it into the box. Liquid nails are suitable for gluing. After the glue dries, the box is puttied.

It is very important to pay attention to the distance from the end of the box to the surface of the wall. In fig. 4, this distance is designated as “t”. If the installation box is steel, and the distance from its end to the wall surface is less than a millimeter, then a circle is guaranteed to appear on the wallpaper glued in this place - rust will come to the surface.

Old metal boxes, which are still common in our homes, rust quite strongly - after all, when gluing wallpaper, the glue can dry out for a day. And all this time the box will be subject to moisture. In the case of painting the wall, rust will also not take long. Therefore, a metal box, if it is very close to the wall surface, should either be carefully bent inward or replaced with a plastic one.

See also at i.electricianexp.com:

Installation boxes for sockets

How to connect wires and cables of different sections

How to connect copper and aluminum wires

How to install a box under a wall outlet or switch inside a wall

Why wire twisting is prohibited

Comments:

# 1 wrote: | [quote]

You honestly surprised me by the fact that when connecting two wires, you should remove insulation from them on a section of 25, 30 millimeters, and twist the ends of the pliers.
Two errors at once:
Firstly, a professional electrician removes the insulation from the wire for at least 4 centimeters (to increase the contact area of the wires), and connects the ends of the wire not by twisting (especially pliers), but by wrapping one wire around the other, with your hands, what to rule out any broken wire.

Comments:

# 2 wrote: Victor Ch | [quote]

Volodya,
Hands tried to twist a wire of 4 sq mm? Do not twist.

You will not break a wire with pliers if there is a skill.

By the method of winding, a stranded (soft) wire is connected to a single-wire: a soft wire is wrapped around a single-wire and then tightened with pliers.

And electricians are twisting it with pliers.

Comments:

# 3 wrote: Alexei | [quote]

Therefore, at present, the connection of wires by the method of twisting by the inspectors of the Energy Supervision is not welcome

I don’t know where, but in Cheboksary there are no problems with this. He took courses in Energonadzor and twisting was negotiated as the most reliable connection, but subject to the use of PPE. Proper use! He worked in one state organization and energy control checks with firefighters took place regularly. Regarding the old distribution boxes, they were forced to wind up PPE everywhere, there were no more questions about the quality of the connection.

And about the Wago. Once I was invited to an apartment (one-room apartment), where the refrigerator outlet stopped working.Entering the apartment I felt the smell of burning insulation. They started looking for what and where. We found a distribution box in which these terminal blocks melted intensely. The box was powered by a socket on the refrigerator and light in the hallway and kitchen. What kind of load can there be with two bulbs? Now I use Wago only in the repair process for quick assembly of temporary shelters for lighting and other things. Then I throw away from sin.

Comments:

# 4 wrote: | [quote]

I also agree about the twist. If it is done well, then this is a guarantee that it will serve well for many years. And various terminal blocks are always a risk. Once, while I was sorting out the distribution box, what was going on, the two self-clamping terminal blocks simply flew off, only from the fact that I lightly opened the wires. What quality of the compound can then be talked about.

Comments:

# 5 wrote: dmitry | [quote]

It is better to entrust such work on planning and installing or moving sockets and switches to a professional electrician.

Comments:

# 6 wrote: Nikolay | [quote]

When moving the outlet, you first need to remove the installation box of the old outlet and the wire to the junction box. In such a box, as well as in the new location of the outlet, there is a supply of wires. It is necessary to check their condition and remove the pliers that are connected by welding with pliers. In the connection made by pressing, there is a reserve, which is also removed by pliers. If there is no stock, then the aluminum coupling at the tip is cut off. Twisted wire connections are carefully disconnected. Next, a new wire is taken and passed through the old recess for the cable from the junction box to the place where the new outlet will be. It is not safe to connect old and new wires, overheating and melting are possible, and the contact will burn. To place a new outlet not just below from below the old place, but also, for example, in the other direction, you need to make new recesses for the wire in the right direction. It is convenient to make such recesses with a stroborez. This is an expensive tool, but you can use the rental. The recesses will be the desired depth and width, even and accurate. If there is no opportunity to use a chamfer, a grinder will help. Everything will be not so perfect, and even dust in the process (do not forget to wet the wall with water), but it will make a notch. Then the wires are neatly laid out on the socket without touching each other, poke into the holes provided and the socket is attached to the wall.

Comments:

# 7 wrote: | [quote]

I don’t believe these terminal blocks, and I can say that they haven’t come up with anything better than simple twisting.

Comments:

# 8 wrote: | [quote]

According to the new PUE, it is impossible to connect with twisting, but from experience, on a 2.5 mm monolithic copper wire you can’t imagine anything better, especially if you strip it to a length of 50 mm. twisting, of course, with hands is hard, only with pliers.

Comments:

# 9 wrote: MaksimovM | [quote]

Yuri, and if the copper twist is additionally soldered, then the contact connection will be even more reliable, which can be insulated, hidden and forgotten about it for many years.

As for laying a new wire, this is not always possible or impractical. For example, the cable that supplies the outlet is routed directly from the distribution panel. If there is a need to transfer the outlet a certain distance, then it is impractical because of this to change the cable, especially if it is in good condition.

Therefore, it is easier to simply increase the required cable length. In addition to soldering, you can use welding or crimping to connect the cables. Such contact connections will be reliable, so they can be hidden in the wall, leaving no access for their periodic inspection.

If you use terminal blocks, including Wago, then it is imperative to provide for the possibility of their periodic inspection and revision.But to ensure high reliability, it is better to give preference to soldering, welding or crimping, especially if a large load is included in this outlet. And from an aesthetic point of view, the presence of another junction box in the room is unacceptable.