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Repairing Aluminum Wiring - US CPSC Publication 516: This is the original U.S. CPSC document explaining the hazard of solid conductor aluminum electrical
circuit wiring, and recommending the use of the AMP TYCO COPALUM special crimp connector to pigtail copper to the aluminum wires as an alternative to complete re-wiring of the building. This document was scanned from the original CPSC document explaining how to recognize the presence of an aluminum wiring hazard and how to repair aluminum wiring. Edits or comments by Daniel Friedman, added for clarification, update, or to provide links to current sources of the AMP COPALUM Connector equipment and specifications are
included in this document in [italicized brackets.] For in-depth information about the aluminum wiring hazard and for description of alternative repair
methods when the methods recommended here are not available, see More Information below. Readers are welcome to make and freely distribute printed copies of this article. For the latest US CPSC publication on aluminum electrical wiring see Aluminum Wiring - CPSC Publication #516-PDF.
ALUMINUM WIRING [the history of aluminum electrical wiring and the aluminum branch circuit wire fire hazard]
U.S. Consumer Product Safety Commission Aluminum Wiring Repair Recommendations
U.S. Consumer Product
Washington DC 20207
On April, 28,1974, two persons died in a home fire in Hampton
Bays, New York. Fire officials determined that the fire was caused by a
faulty aluminum wire connection at an outlet.
Since that tragic accident, 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
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 [of overheating aluminum wiring]
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.
1 The survey conducted by the Franklin Research Institute defined
"Fire Hazard Conditions" to occur when receptacle cover plate mounting screws
reached 149~C (3O0~F), or sparks were emitted from the receptacle, or materials
around the receptacle were charred.
WHAT THE HOMEOWNER CAN DO [to repair unsafe aluminum electrical wiring ]
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. (Note - The marking "CU-clad" or "Copper-clad" in addition to
the "Al" or "Aluminum" means that the cable uses copper-coated
aluminum wire and is not covered by this message.)
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
CAN THE [aluminum wiring] 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
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
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. The metal sleeve
is called a COPALUM parallel splice connector and is manufactured
only by AMP Incorporated. This special connector can be properly
installed only with the matching AMP tool. This tool makes a
permanent connection that is, in effect, a cold weld. An insulating
sleeve is placed around the crimp connector to complete the repair.
[Aluminum Wiring "Repair" Methods NOT Recommended by the US CPSC]
Two other repair methods are often recommended by electricians.
While these repair methods are substantially less expensive than
COPALUM crimp connectors, neither of these repairs is considered
acceptable by the Commission staff.
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 Commission staff has evaluated the
effectiveness of "pigtailing" as a repair. In OPSO-sponsored laboratory
testing some brands of twist-on connectors have performed very
poorly. Over time, substantial numbers of these connectors have
overheated in laboratory tests. Surveys of and statements made by
electricians and electrical inspectors confirm the highly variable and
often poor performance of these connectors when used with old
technology aluminum wire. It is possible that some pigtailing "repairs"
made with twist-on connectors may be even more prone to failure than
the original aluminum wire connections. Accordingly, the Commission
staff believes that this method of repair does not solve the problem of
overheating present in aluminum branch circuits.
"Pigtailing' Is Not a Recommended Repair
The other repair recommended by the industry uses switches and
outlets labeled "COALR". 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/ALP connectors are not
available for all pat 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. Further, CO/ALP
wiring devices have failed in laboratory tests when connected to
aluminum wire typical of that installed in existing homes. The test
conditions simulated actual use conditions; no "overstress" type of
testing was used.
Exception: If you have an aluminum wire termination in your home
which exhibits symptoms of failure, twist-on connector pigtails or
CO/ALR devices may be used as an emergency temporary repair for a
failed aluminum termination. Should such a repair be performed, the
Commission staff recommends that you arrange to have your home
rewired or the COPALUM crimp connector repair performed as soon
It is important to note that there is only one manufacturer of the
special connectors and the tools required to make the repairs as
recommended by the CPSC staff.
WARNING [about other wire connectors and crimp connectors and aluminum wiring ]
There are many other brands and types of crimp connectors -
including those intended to be installed with a pliers type of hand tool -
which are readily available to consumers at hardware stores, lumber
yards, hobby supply stores, automotive supply stores, and so forth.
THE COMMISSION STAFF DOES NOT BELIEVE THAT THESE
COMMON VARIETIES OF CRIMP CONNECTORS CAN BE USED TO
RELIABLY REPAIR ALUMINUM WIRING.
THE [AMP TYCO]COPALUM CRIMP METHOD OF REPAIR [for aluminum wiring in buildings]
The precision dies in the COPALUM tool squeeze the connector
and wires into a particular shape which was determined during the
design of the COPALUM wire connector. Both the final shape of the
connection and the amount that it is squeezed (deformed during
crimping) are critical in making a reliable crimp connection. Upwards of
10,000 pounds of force is necessary to obtain the amount of
deformation for which the connector is designed.
In addition, electricians who are authorized to install COPALUM
connectors are thoroughly trained by the manufacturer to use the tool
properly. The Commission staff emphasizes that this training is
necessary to assure that the electrician uses the careful, professional
workmanship required to make the crimp connector repair safe and
How the [AMP TYCO]COPALUM Crimp Method Works
[How to Use The AMP COPALUM] CRIMPING PROCEDURE
Follow the procedure below with attention given to steps 1 thru 4.
(1) Use the correct tool and dies (recommended by the AMP
field representative) for the splice being crimped. Ensure
that the color coding and marking designation on the splice
correspond to the color coding and marking designation on
(2) Be sure the perforated liner is inside the splice. The ends of
the liner are flared to prevent removal.
(3) Load the splice into the dies of the tool.
(4) Insert stripped wires into the splice until the ends of wires
extend beyond end of the splice. Wires should be parallel in
the splice. Insulation of the wire MUST NOT ENTER the
You should request a copy of AMP literature from your electrician
prior to his beginning work. Discuss with your electrician any
information in the literature which you do not understand. Remember,
every connection of aluminum-to-aluminum or aluminum-to-copper
wire in your home should be repaired in order to obtain the maximum
benefit from such repair work.
All appliances connected directly to #12 or #10 AWG 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.
To determine whether the COPALUM crimp connection method
of repair is available in your area, you may wish to write or call the
manufacturer of the COPALUM connector for a list of authorized
electricians who are doing aluminum branch circuit repair work in your
area. You may write to:
[DJF NOTE: the following address which appears in CPSC #516 is OBSOLETE]
AMP Incorporated Att: Aluminum Wire Repair Program Mail Stop 140-13 P.O. Box 3608 Harrisburg, PA 17105-3608 PHONE: 1-800-522-6752
[15 January 2008 DJF note: We add the following update and detail to this US CPSC document: Consumers and electricians may have difficulty obtaining further
information, advice, or equipment from AMP or the successor distributor, TYCO, for the COPALUM connector and aluminum
wiring repair. Consumers and electricians needing to evaluate or repair aluminum wiring should see Reducing the Fire Hazards in Aluminum-Wired Homes, details of the hazard of and what to do about aluminum wiring, aluminum wiring repair methods, aluminum
wiring failures research, field and lab experience, expert sources. This document answers most technical questions about the hazards
and remedies of aluminum electrical wiring.
The Commission staff wishes to remind you that 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.
[DJF note: Consumers should make certain that their electrical inspector or electrician is fully familiar with the hazards of aluminum electrical wiring, and fully trained in proper repair methods for aluminum wiring. Improper repairs using improper devices or equipment, or incomplete repairs, such as failure to address every
connection in the building, or using non-recommended parts and devices, may actually increase the risk of a fire or loss.]
7 Elements of Key Aluminum Wiring Repair Advice Home Inspectors Should Give to their Clients
Aluminum Electrical Wiring repairs in a home where that work has not been performed will be a significant expense
Aluminum wiring repairs should not be deferred, as the risk increases with age and use of the electrical system; meanwhile be sure that the home has working smoke detectors, and turn off any circuits behaving oddly.
Aluminum wiring repairs should be performed only by a licensed electrician who is well informed about the correct repair methods. Using an improper repair method may actually increase the risk of a fire. See ALUMINUM WIRING REPAIR ELECTRICIANS
Do use one of the following aluminum wiring repair methods:
Do not use any of these aluminum wiring repair methods
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 "Record of Commission Action, Commissioners Voting by Ballot", CPSC Publication No. 516, Repairing Aluminum Wiring (original version op.cit.), (Briefing package dated March 15, 2011), Quoting: The Commission voted unanimously (5-0)·to approve republication of CPSC Publication No. 516, Repairing Aluminum Wiring, with the explicit recognition that the COPALUM and AlumiConn connectors currently are the only products that meet the agency's standards to prevent aluminum wire fire hazards Copy on file as /aluminum/Pub516_Alumi_Conn.pdf
 Dr. Jess Aronstein, email@example.com is a research consultant and an electrical engineer in Schenectady, NY. Dr. Aronstein provides forensic engineering services and independent laboratory testing for various agencies. Dr. Aronstein has published widely on and has designed and conducted tests on aluminum wiring failures, Federal Pacific Stab-Lok electrical equipment, and numerous electrical products and hazards. See Aluminum Wiring Bibliography and see FPE HAZARD ARTICLES, STUDIES for examples.
 "The Influence of Corrosion Inhibitor and Surface Abrasion on the Failure of Aluminum-Wired Twist-on Connections",
Aronstein, J.; Campbell, W.,
Components, Hybrids, and Manufacturing Technology, IEEE Transactions on
Volume 7, Issue 1, Mar 1984 Page(s): 20 - 24
Reducing the Fire Hazards in Aluminum-Wired Homes, [.PDF document], Jess Aronstein, Ph.D., 21 May 2007. This document answers most technical questions about the hazards and remedies of aluminum electrical wiring and includes
a report on independent test results of alternative products and methods for repairing aluminum wiring. Some of the sections of this very thorough document are listed below:
Reducing the Fire
Hazards in Aluminum-Wired Homes,details of the hazard of and what to do about aluminum wiring, aluminum wiring repair methods, aluminum
wiring failures research, field and lab experience, expert sources. This document answers most technical questions about the hazards
and remedies of aluminum electrical wiring. UPDATED 3/5/2003, Edits-df 12/05/2005
1 May 2003 - U.S. CPSC announced that Tyco Electronics Corp. will continue offering the COPALUM connector repair system until at least 2005 - for details see the Tyco Press Release.
AMP Corporation, Harrisburg PA 17105 800-522-6752 - CPSC's recommended COPALUM aluminum-copper retrofit - US Customer Support 800-522-6752 [See the TYCO announcement above]
AMP Canada Product Information Department, 905-470-4425 the COPALUM connector line is available in Canada; they do not appear to have a contractor training/certification program such as is (at least in a few places) available in the USA.
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NEW ORLEANS, LOUISIANA, ORLANDO, FLORIDA, PHILADELPHIA, PENNSYLVANIA, PHOENIX, ARIZONA, PITTSBURGH, PENNSYLVANIA, PORTLAND, OREGON, ROCKVILLE, MARYLAND, SAN JUAN, PUERTO RICO,
SEATTLE, WASHINGTON, ST. LOUIS, MISSOURI, ST. PAUL, MINNESOTA, TULSA, OKLAHOMA
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Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. Field inspection worksheets are included at the back of the volume. Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
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