The Problem: Fire Hazard
Connecting aluminum and copper conductors is like a boxing match: in one corner is the resilient and inexpensive lightweight aluminum (Al). In the other corner, the superconductive and more expensive standard copper (Cu). If a conductive liquid (such as water condensation) is added to the fight, an electrochemical reaction occurs: the copper decomposes the aluminum, increasing contact resistance and temperature. This mixture could result in a fire.
Relatively Rare in Building Installations
Connecting aluminum and copper conductors: This is a challenge that electricians in building installations rarely face. And this is confirmed by Volker Kuhlmann, ELECTRICAL INTERCONNECTIONS technical customer consultant at WAGO. Nevertheless, “Especially in older buildings within the states of what used to be East Germany, you can still find installation cables with aluminum conductors.” When renovating or extending these electrical installations, electricians face the problem of having to connect or distribute from the old aluminum conductors to copper conductors. “These connections and distributions can occur in junction boxes and existing building distribution boards,” Kuhlmann notes.