Wiring in houses of old wiring most often does not meet the requirements that have developed in our time. The use of many household appliances and increased loads involve the replacement of entire sections or the entire distribution system in an apartment or house. In doing so, keep in mind the basic rules connect aluminum wire to copper current conductor in order to prevent accidents.
After all, the situation when you want to make an insert of copper wire into the existing aluminum wiring is very common. It is not recommended to do this, but if you already had to face a similar problem, everything must be done to avoid a fire as a result.
Reasons why this method of connection is prohibited
A good example showing the danger of such a procedure is the principle of operation of a galvanic cell, which is described in the school curriculum. from a different metal is similar to the appearance of current in a conventional battery, due to the process of interaction in the electrolyte of two different materials.
In conditions of dry air, the probability of such a phenomenon is almost zero. Therefore, for some time, even under conditions using powerful devices, the junction will last for a certain time. But the consequences will still be very unpleasant.
Gradual destruction leads to the fact that the resistance parameters of materials will steadily increase. There is a significant heating of the connection zone at the moments of connection of high-power consumers of electricity. With frequent use, the risk of fire increases many times over.
Therefore, long-term docking of current conductors from different materials is not recommended by experts. In case of emergency, you will need to study a few tips.
Scrupulously using the scientific method is not always possible, but in any situation, do not forget what is most effective. A simple and safe technique is available for a quick procedure even by an electrician with little experience. Three types of such connections are most often used.
Method "Nuts"
The specific form of the elements for the time-tested variant gave this name. The main component of the design is three plates designed to fix wires between them.
The insertion of the second wire is made without the need to cut the central line. All that is required is the stripping of the insulating layer at the junction for subsequent clamping between the "nuts". The lead wire is placed between the plates and twisted.
They have excellent characteristics in terms of reliability and simplicity. The docking process takes just a few seconds. Everything happens in an accessible form - the ends of the conductive wires are stripped and inserted into the connectors intended for this.
Galvanic reaction and oxidation are prevented by a special lubricant that fills the interior. But in the case of powerful devices, this technique is not very effective. The optimal scope of use is the connection of lighting devices.
pads
The connection process is similar to that discussed above, but with consumers with high power, they are much more reliable. Sufficient thickness of the plate is able to withstand significant loads. It should be remembered that installation in conditions of high humidity is better not to do. The absence of an insulating lubricant can provoke the appearance of a galvanic couple.
Bolted fasteners
The articulation of aluminum and copper is also allowed in this way. For a correctly performed clamping procedure, a washer made of anodized steel is placed between dissimilar metals. At least twice within 12 months, a strength test is performed. More frequent maintenance is mandatory in a network with high loads.
soldering iron
This method requires certain conditions to be met.
Copper is soldered very easily, but with aluminum there are problems. The chemically resistant amalgam resists soldering and confuses novice electricians.
You can eliminate this layer like this - after cleaning the soldering area, apply a few drops of copper sulfate to it. Then a copper wire is connected to the positive pole of the Krona battery, and an aluminum conductor is connected to the negative pole. Soon, a deposit of a layer of copper suitable for soldering forms on it.
Note! All considered methods provide for rigid fixation of the stripped conductors. But when twisting wires from different metals, for some reason they forget about this requirement.
For aluminum, a characteristic feature is ductility under high loads, which is also called fluidity. Only regular maintenance and tightening of the clamping elements will save you from burning the terminal due to high overheating.
Some Tips
- stranded copper wires should not be clamped;
- select a terminal with a channel corresponding to the wire section;
- the increased fragility of brass sleeves and terminals is the reason why you should avoid pinching;
- pay attention to the marking with the indicated current strength.
Sleeve connections
It is best to use such a device to connect an aluminum tap to a stranded copper wire. A "pigtail" freed from insulation, consisting of twisted veins, is inserted into the hollow tip. After crimping with pliers, the tip is inserted into the terminal.
Twisting
When twisting a stranded conductor, be sure to cover the "pigtail" with solder to ensure good contact. And it is recommended to cover the ends with insulating caps.
In conditions of high humidity, such a connection is not recommended. The destruction of the docking site is fast.