The increase in the use of preassembled aluminum cables to replace old copper lines requires special attention. In this article, it is a question of establishing the mathematical equations which define the functioning of a network constructed with preassembled aluminum cables. To use this mathematical model, a test network was created, with four cables of 460 IEEE configuration. Our analysis are mainly based on the rate of imbalance and the voltage drops that these lines thus formed can generate. We propose a modified “Forward/Backward” algorithm to execute this analysis. On the test network, two cable layouts were approached, namely a so-called “polygonal” layout and a second so-called “linear” layout. The first layout gives us maximum voltage imbalance rate in 0.0083% and a maximum voltage drop in 1.5%. The second layout gives us very similar results. So, we can consider that the layout has an insignificant impact on lines performances.