In the matter of connecting copper and aluminum wires, it’s time to recall the already forgotten and hackneyed joke about “You can’t just take it and ...”. And all because you really can’t just take and connect aluminum and copper wires together. So let's try to figure out how much and how to do it right.
Why can't you just "twist" copper and aluminum wire?
It is strictly forbidden to twist aluminum and copper wires for fire safety reasons! It is possible to connect copper and aluminum wires only through a third material, a special adapter. This is because copper and aluminum have different coefficients of thermal expansion. Due to the difference in the expansion-contraction of materials, the geometry of the conductor is disturbed, the contact becomes loose. Further, due to poor contact, heating and an electric arc appear. At best, such a connection will simply cease to fulfill its functions. Although most likely, it will burn down and may even cause a fire.
What methods are allowed for connecting copper and aluminum wires
Sleeve pressing. We go to the store and buy there “aluminum-copper sleeves” or simply GAM. In the center of such a sleeve there is a special partition-adapter. It is very important to correctly insert each wire into its end of the sleeve: copper to copper, aluminum to aluminum. Next, the sleeve is pressed with a suitable tool.
>>>>Ideas for life | NOVATE.RU<<<<
Terminal blocks. In the same store you can buy special "terminal blocks", adapters for one or more pairs of wires. It is very important not to save on pads, but to choose from trusted manufacturers, as you often come across frankly defective ones that burn out already for 2-3 years of operation. The principle of operation of the terminal block is almost the same as that of the sleeve.
"Grandfather Method". If there is no opportunity, time or desire to run around the shops, then you can resort to the “old-fashioned” method that has been proven over the years and make a handicraft adapter. To do this, you need a bolt, nut and three washers made of neutral material. First, one washer is thrown onto the bolt, the first wire is wound. It is covered with a second washer, which is thrown over the wire from above, then the second wire is wound. It is also covered with a washer from above, after which the whole structure is carefully assembled and clamped with a nut.
In continuation of the topic, read about does it make sense to use tubes in a concrete wall.
A source: https://novate.ru/blogs/101221/61511/