Correctly connecting al and cu
Aluminium and copper: how to connect them
- Combining aluminium and copper is problematic.
- High-quality Al/Cu compression cable lugs are perfect for coupling aluminium conductors with copper elements.
- A compound in the aluminium connecting material improves the contact properties.
- Aluminium-copper connectors are necessary for the skilled connection of aluminium and copper conductors.
We want to focus on the not-so-simple task of connecting aluminium and copper. As previously mentioned, aluminium is used quite often, but not always on its own. As copper has been the material of choice for decades, and continues to be used, there are problems in safely connecting both materials. In practice, electrical engineers are faced with this challenge more and more often.
Connecting aluminium and copper is required more often than you might think. For example, it is necessary if an aluminium ring conductor is located in an industrial area, but the adjacent plants are supplied via copper conductors. Even in transformer stations, aluminium conductors need to be connected to copper bars.
Electrical engineers are confronted with the problem that aluminium and copper are not easily connected. For a durable and secure connection, special Al/Cu cable lugs and connectors should be used.
Reduction connectors are often used in network repairs – more specifically in the production of non-tension connections for aluminium conductors in accordance with DIN EN 60228, and copper conductors in accordance with DIN EN 60228. The connectors are made of two components: aluminium parts (E-Al) and copper parts (pursuant to EN 13600). The aluminium side generally has a larger diameter, because the lower conductivity is compensated by a correspondingly higher nominal cross-section.
As with compression cable lugs, the aluminium side of the connector also contains a compound, which is prevented from running out and drying out by a protective cap.
To ensure safe results when processing the Al/Cu compression joints, follow the relevant copper and aluminium processing specifications.
When using compression connectors underground, make sure that the joints are protected from moisture. It is best if you use a cast resin joint. The joint permanently protects the connections from moisture, dust and the penetration of foreign bodies.
Lastly, an important note on aluminium and copper cable lugs and compression joints: Do not expose these products to bending stress, otherwise there is a risk of breakage at the contact point between the two materials. Use in the overhead line sector is therefore not possible.