The U.S. Consumer Product Safety Commission staff and other government officials have investigated numerous complaints from homeowners throughout the nation who have had trouble with small gauge aluminum branch circuit wiring. The Commission has also had research conducted that shows that homes wired with aluminum wire manufactured before 1972 ("old technology" aluminum wire) are 55 times more likely to have one or more connections reach "Fire Hazard Conditions" than is a home wired with copper.

The hazard investigated by the Commission staff occurs at connections to old technology aluminum wire, such as at outlets or switches or at major appliances such as dishwashers, furnaces, etc. Corrosion of the metals in the connection, particularly the aluminum wire itself, causes increased resistance to the flow of electric current and that resistance causes overheating.

Homes built before 1965 are unlikely to have aluminum branch circuit wiring. Homes built, rooms added, and circuits rewired or added between 1965 and 1973 may contain aluminum wiring. In 1972, manufacturers modified both aluminum wire and switches and outlets to improve the performance of aluminum wired connections. Sale of the old style wire, switches and outlets still on dealers' shelves however, continued after 1972.

TROUBLE SIGNS

Signs of trouble in aluminum wire systems include warm-to-the-touch face plates on outlets or switches, flickering lights, circuits that don't work,or the smell of burning plastic at outlets or switches. Unfortunately, not all failing aluminum wired connections provide such easily detected warning signs;aluminum wired connections have been reported to fail without any prior indications or problems.

WHAT THE HOMEOWNER CAN DO

If you have noticed any of the trouble signs, have a qualified electrician determine whether the problem is caused by deteriorating connections to aluminum wiring. DO NOT TRY TO DO IT YOURSELF. You could be electrocuted or you could make the connections worse by disturbing them. If you are not certain whether your home has aluminum branch circuit wiring, you may be able to tell by looking at the markings on the surface of the electric cables which are visible in unfinished basements, attics or garages. Aluminum wiring will have "AL" or "Aluminum" marked every few feet along the length of the cable.

If you do have aluminum branch circuit wiring, the Commission suggests that you have a qualified electrician check the system for impending trouble. Remember, you may not have noticed any of the warning signs, but research shows that trouble may develop over time and an electrician may spot potential problems before you notice them.

CAN THE PROBLEM BE FIXED?

One method of eliminating the risks associated with old technology aluminum wiring terminations is to eliminate the primary cause: the aluminum wire itself. Depending upon the architectural style of your home and the number and locations of unfinished spaces (e.g., basements and attics), it may be relatively easy to rewire your home. A new copper wire branch circuit system would be installed, and the existing aluminum wire would be abandoned inside the walls. This is the most expensive method of repairing an aluminum wired home; but if you can afford the cost, it is also the best method available.

Since it may be impractical to rewire some types of aluminum wired homes (e.g., condominium units), or since rewiring may be prohibitively expensive for some homes (e.g., split-levels with no unfinished areas), the Commission staff attempted to find a repair method which would permit the continued use of existing old technology aluminum wire. The main criteria to be met by such a repair method are:

-- It must permit the repair of every connection to, or splice between,aluminum wire in the home;

-- The repaired connections must be permanent but must result in a system that can be maintained without the need for special switches, wall outlets or other connectors;

-- The repair technique must be practical for use in an occupied and furnished home.

The CPSC-sponsored research, laboratory tests, and demonstration projects identified only one method of repairing existing aluminum wire circuits which meet these criteria. That repair is known as the crimp connector repair.

The crimp connector repair consists of attaching a piece of copper wire to the existing aluminum wire branch circuit with a specially designed metal sleeve and powered crimping tool.

Two other repair methods are often used by electricians.

The first repair ("pigtailing") involves attaching a short piece of copper wire to the aluminum wire with a twist-on connector sometimes called a wire nut; the copper wire is connected to the switch, wall outlet or other termination device.

The other repair recommended by the industry uses switches and outlets labeled "CO/ALR". Underwriters Laboratories Inc. (UL) lists these devices especially for use with aluminum wire, although they can be used with copper or copper-clad wire. CO/ALR devices perform better with aluminum wire when installed carefully and according to best electrical practices than do the types of switches and outlets usually used in the original installations of old technology aluminum branch circuit wiring. However, CO/ALR connectors are not available for all parts of the wiring system (for example, for permanently-wired appliances and ceiling mounted light fixtures). In the opinion of the Commission staff CO/ALR devices must be considered to be, at best, an incomplete repair.

All appliances connected directly to #12 or #10 gauge aluminum branch circuit wiring (for example, dishwashers, cooking equipment, heaters, air conditioners and light fixtures) must be repaired in addition to wall outlets, switches, junction boxes and panel boxes.

All modifications and additions to your wiring system should be done in accordance with local regulations and inspected by municipal authorities. You should insist that repairs to your aluminum wiring be inspected.