Aluminum wiring is a widely used product in the home construction industry. Today, aluminum wiring is used for main service entrance lines and for major appliance circuits in conjunction with an anti-oxidation compound.
In the past, between 1965 and 1973, solid aluminum wires were used for 120-v circuits. The U.S. Consumer Product Safety Commission (CPSC) has performed tests and studies that show homes wired with aluminum wire manufactured before 1972 (“old technology”) are 55 times more likely to have one or more connections reach “Fire Hazard Conditions” than is a home wired with copper.
Over-heating can occur at the connection point between the wire and the outlet, switch, or fixture. There are a few different ways to determine if a safety issue may exist. First, feel for warmth on the surface of the outlets and switches. Next, flip light switches and observe if the lights flicker, this could also indicate a faulty switch. Check as many circuits as possible because one or more may be inoperative. Pay attention to unusual odors because the heat my actually melt the plastic portions of the switch/receptacles.
There are some options in the removal of the hazard. The first, and safest but most expensive, is to rewire all circuits containing aluminum wiring with copper. Circuit connections that have already failed need to be re-wired for safety. Experiments by the CPSC have revealed that pigtailed connections and crimped connections (unsatisfactory repair methods) are even more prone to failure than the original connections. The final way to remedy the situation is to use a Coplum Crimp Method. This method is recommended by the CPSC on stranded cable over #8 gauge wire, but is not allowable for solid conductors. A metal sleeve called the Copalum parallel splice connector is placed over both wires and then crimped using the Copalum tool. This device exerts upwards of 10,000 lbs to create, in effect, a cold fusion bond.
The final and maybe best recommendation would be for the client to install “ARC Fault” breakers on all aluminum and Knob and Tube circuits in the dwelling until replacement of existing cables can be accomplished. This method may require the installation of a branch panel or replacement of the existing main panel. This will provide protection in the event that the failed conductors cause the Arc Fault breaker to trip. Operation of the breaker will render the circuit harmless. As a note of interest, in 2008 the ICC/IRC will be requiring that all 120-volt circuits in new homes be protected with Arc Fault breakers.
Written by, Brett Hodgdon, firstname.lastname@example.org