Restrictive connector terminal solutions can be an issue when specifying aluminum wires for automotive applications.
In light of time-to-market issues in the automotive industry, aluminum is the best option for reducing the weight of the electrical distribution system and harnesses.
Aluminum has been used in battery and power applications in premium cars for some time. Now, LEONI is delivering aluminum battery cables for mass production cars such as the new Renault Twingo. The weight savings is also extremely advantageous in mid- and low-power applications for main distribution and standard harnesses. In addition, aluminum is also less expensive than copper wires.
However, during processing, aluminum wire is less fault-tolerant than copper wire. For the last two years, LEONI experimented on aluminum wires in both laboratory and plant environments with different combinations of terminals and wires because the wire structure is a key consideration for a reliable crimping process. The first industrial tests show good results. The CFM (Crimp Force Monitoring) has ensured the detection of the relevant defects.
For now, connector suppliers offer terminal designs that specify restrictive combinations of wire sources and crimping processes to guarantee users achieve a positive result. This means harness makers are limited to using the specified wires and process equipment required by the terminal solution they choose. Typically, two to three connector manufacturers will supply a typical car manufacturer. Without standardization, the harness suppliers may have to set up specific wire-cutting rooms and purchase specific wires for each terminal solution.
The connector manufacturer that designs a terminal that works with any wire and meet all international specifications will have the best chance of setting a standard for aluminum wiring in automotive applications.
Aluminum wire is an excellent choice for automotive applications in terms of time to market and cost benefits. But in order to widen its implementation, OEMs must push for standard processes across terminal suppliers that work with every wire source.
Louis Chrétien is component development director, aluminum program, at LEONI.