Research & Writing Assignment:
Inspecting aluminum branch wiring is important because of it’s less than desirable qualities as opposed to copper branch wiring. Aluminum branch wiring was used between 1965-1973 due to rising costs for copper. In those years of use aluminum wiring’s weaknesses became apparent. Compared to copper, aluminum wiring degrades faster undergoing galvanic corrosion when coming in contact with different types of metals in the presence of moisture & will oxidize a lot faster than copper wiring making aluminum wiring less conductive. Other undesirable qualities are higher resistance which requires larger aluminum wiring to be used for the same load as smaller sized copper wiring, less ductile than copper which will cause fatigue in the wire sooner, more malleable which makes aluminum wiring deform when over-tightened, thus creating a loose connection and possible fire hazard, greater thermal expansion and excessive vibration which also contributes to loose connections.
Aluminum wiring can be identified by it’s color and/or the word aluminum or AL on the wire jacket. Other ways to identify aluminum wiring are by wiring terminals marked CO/ALR which means copper/aluminum revised or by the date a home was built.
The best way to correct aluminum wiring is to replace it with copper wiring. Another method and the second best way is to use copalum crimps. Pig tailing, CO/ALR connections and alumiconn are other ways to correct the aluminum wiring, but are only recommended as a temporary fix. Replacing failure prone devices with one’s that are compatible with aluminum is an option as well. It’s also recommended that ignitable materials are not near the connections.
As we can see by the hazards that aluminum wiring presents it’s very important to verify whether or not it is present. If aluminum wiring is found to be present, it is required to be reported.