When repairing flats in old houses built from the economy, you can leave some of the old wiring with aluminum conductors, which need to be combined with the newly made using copper cables.
Conventional twist here is not applied, because aluminum with copper to form a galvanic couple, the contact area which is exposed to an intensive corrosion by current flow and the presence of even a minimum amount of atmospheric moisture. Corrosion accompanied by an increase in contact resistance, which leads to heating of the contact area and can cause a short circuit followed by ignition or burning-off wires.
Ways of dealing with the electrochemical corrosion
To suppress the corrosion process is carried out, you can use two approaches
- blocking access of air into the contact region, which reduces almost to zero the intensity of the chemical reaction;
- physical separation of copper and aluminum conductors, which completely eliminates the cause.
The first approach is actually recommended SAE, 7th edition, paragraph 2.1.21 of which requires the use of additional crimping, welding or soldering connected conductors.
Any of the methods of this group is highly efficient and allows you to splice the minimum size, but technically difficult to implement.
Therefore, in the home use simpler approaches the second group, which are involved to implement the various elements or simply purchased means available.
Terminals
Called terminal block connector clamping mechanism fixation wires. It is easy to install simply stripped wire end is inserted and is pushed into the slot without much effort. Bonding wires are held by the contact of execution in the form of the end of a fishing hook.
Capacity connection reliability is achieved:
- using a transparent body, allowing to control the depth of feed wires Figure 1;
- filling slot a sealing gel neutral paste internal space.
Clip-walnut
Clip-walnut, got its name from the characteristic shape of the body refers to the purchased components. Structurally represents at least three sites, the gaps between which is inserted the exposed ends of the wires to be connected, and then tightening the screws resulting regular structure.
Ready splice is placed in a plastic housing, which provides inputs for connect the wire, see Figure 2.
clamp removal and reuse can perform an unlimited number of times.
bolted connection
Bolted connection form of scrap tools. Spatial separation of copper and aluminum is provided with steel washers. The ends of wires to be connected after the stripping folded rings, through washers, the diameter of which exceeds the outer diameter of a ring, worn on the bolt, whereupon the nut is tightened.
The resulting structure is shown in Figure 3.
Strengths of the compound - the ease of implementation, the possibility of forming a branch and the main drawback - the large size of the resulting splice.
To increase reliability
- use non-galvanized bolt and washer;
- Flare set grower.
Connect the barrel
The implementation of this type of adhesion is based on mechanical fixing ends spliced wires bimetallic sleeve, Figure 4. After entering the wire liner is pressurized, and then further isolated if appropriate. The strong point of the gland connection - compactness of the resulting splice.
To increase the reliability of fixing sockets operate blind and do not produce molding pliers, a special tool with a working body of circular or hexagonal shape.
conclusion
Copper and aluminum wire is allowed to connect when performing simple rules.
The compound in the home by using available tools or simple standard components.
Selection of a particular method of compound depends on the installation place preference electrician and availability of supplies.