Aluminum Wire - Upgrading or Repairing Aluminum-wired Homes

Upgrading or Repairing Aluminum-wired Homes

There are several upgrades or repairs available for homes with pre-1974 aluminum branch circuit wiring:

• Completely rewiring the house with copper wires.

• "Pigtailing", which involves splicing a short length of copper wire (pigtail) to the original aluminum wire, and then attaching the copper wire to the existing electrical device. The splice of the copper pigtail to the existing aluminum wire can be done with special wire nuts, special crimp connectors, or special miniature lug-type connectors.

The Consumer Product Safety Commission (CPSC) recommends that for a permanent repair, the pigtailing be done with special crimp connectors called COPALUM, or a special miniature lug-type connectors called AlumiConn connectors. And any repairs should be done by qualified electricians familiar with aluminum wire problems and repair methods.

COPALUM connectors are a sophisticated crimping system that creates a cold weld between the copper and aluminum wire, and is regarded to be a permanent, maintenance-free repair. These connections are sometimes too large to be installed in existing enclosures. Surface enclosures or larger enclosures may be installed to remedy this problem. COPALUM connectors can be costly to install and must also be done using special tools by electricians certified in its use, and it can be difficult to find local certified electricians.

As of April 2011, the CPSC has also approved the AlumiConn miniature lug connector as an alternate to the COPALUM connectors for a permanent repair. The AlumiConn pigtail connectors are easier for local electricians to install as they only require the electrician to use a special torque screwdriver.

CPSC considers the use of pigtails with wire nuts a temporary repair, and there have been some problems reported. In some cases using pigtail wire nuts can increase the risks of a fire. However it is believed that the problems are primarily related to improper installation procedures or products. The manufacturer of one brand of wire nut, often used for this purpose, has stated that special procedures are required when using the wire nuts to pigtail older pre-1970s ("old technology") aluminum wire, such as pre-twisting and slightly abrading the wires, and the manufacturer of another brand has stated that they are not to be used for retrofitting older aluminum wiring, even though some websites recommend their use. Presently Ideal No. 65 wire nuts, which are a distinctive purple color are the only wire nuts listed by UL for repairing aluminum wiring. However these are described by their manufacturer as not suitable for permanent retrofit of aliminum wiring in testimony to the CPSC leaving the COPALUM and AlumiConn systems as the only systems approved by the CPSC and unequivocally recommended by their manufacturers as safe for permanent long term retrofit of older aluminum wiring. Properly installed wire nuts by qualified electricians using approved products and special installation procedures can offer a viable option for a temporary repair to improve the safety of older aluminum wiring, but should not be considered a permanent correction of the problem.

Also some incorrectly believe that repairing older pre-1970s aluminum can be done by replacing electrical devices (switches, outlets, etc.) with ones that are rated for use with aluminum wire (CO/ALR rated devices). The problem is that these modern devices are tested and listed using modern AA-8000 series alumimum wire, which is very different than older pre-1970s aluminum wire which expands and contracts much more, and is more susceptible to creep. So the CPSC considers using CO/ALR devices for older aluminum wiring only an emergency repair.