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This page continues the description of a working alternative repair method for aluminum wiring [- Superceded by new alternate repair as of June 2007 -] in which copper pigtails are spliced to the aluminum wire ends using a specific twist-on connector, antioxidant, abrading, and pre-twisting of the wires. Independent testing of this method indicates that provided the work is performed correctly these splices perform well and can significantly reduce the risk of aluminum-wire caused fires in buildings.

This repair may be appropriate for cases where the AMP TYCO COPLAUM connector method and electricians trained to use that method are not available.

This is Aluminum Wiring Repair Procedure - Page 12b Color photos and descriptive captions from CPSC Meeting 9/28/95. In this document aluminum wire twist-on connector failures and repair procedures are described, including aluminum wire repair methods which work and methods which do not work and are unsafe.

Color photos of aluminum wire repair procedures, and photos of failed connectors are included. This document describes hazards with existing products, explains the aluminum wiring failure mechanism, and reviews recommended retrofit procedures including use of readily-available materials. This information was presented to the US Consumer Product Safety Commission by Dr. J. Aronstein, 9/28/95.

The minutes of that US CPSC meeting were obtained under the Freedom of Information Act and posted by Daniel Friedman January 1996.

Special Aluminum Wire Repair Method For Use When the COPALUM Method is Not Available - Page 2 of 2

Click on the thumbnail sketches below to see each full-sized illustration.

42. Here is the pre twisted wire splice.

There is substantially better mechanical and electrical wire-to-wire contact in this pre-twisted splice than can be achieved by simply screwing the connector onto the straight wires.




43. The excess length of the twisted wire splice is then cut back to the length specified for the connector that is to be used.



44. The connector spring is filled with inhibitor.

The connector that has been found to work well for aluminum and aluminum-copper splices (3M Scotchlok, available from most electrical wholesalers) has several features that make it intrinsically safer than the Ideal #65, including a non-flaming shell, a metal shell around the spring, and heavier spring wire.

The 3M "Scotchlok" connectors are generally available in four sizes, designated on the box (of 100) as product model "Y", "R", "G", or "B" (in increasing order of size). The model designation corresponds to the color of the insulating shell (yellow, red, green, or blue). The "R" and "G" are the most useful sizes for aluminum wire pigtailing of the #12 and #10 wire (15 and 20 amp circuits, respectively).


45. The connector is applied to the pre-twisted wire splice.




46. The connector is screwed on tightly. This may result in the extrusion of some exhibitor compound out of the connector. This excess should be removed. Scroll Down to Rest of This Page

47. Here is the finished splice. This same type of twist-on connector is available in other sizes as required for various wire combinations.

Other brands and types may be OK. The key factors are: "live spring" design, non-flaming shell, heavy spring cross section, and non-steel spring if available.



48. The installation technique is pivotal. In long-term tests, only the groups made with the installation procedure described have been stable without any increase in resistance (Group A). Serious long-term degradation is seen (Group C) when the same connector is conventionally installed.



49. The results of many years of long-term tests on aluminum and aluminum-copper splices show conclusively that the abrasion/inhibitor/pre twist installation method shown overcomes the basic failing of the twist-on connector by establishing sound wire-to-wire contact.

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Aluminum Wiring Repair Methods - CPSC Meeting 9/28/95
  Contents
  Copper Pigtailing
  Pigtailing failures
  Additional failures
  Field Failures
  Wire-to-wire Contact
  Equivalent Circuits
  Current Flow
  Connection Deterioration
  UL Test Inadequate
  "Special Connector" Failures
  AMP TYCO COPALUM
  Alternative Repair
  Special Concerns
ALUMINUM WIRING HAZARDS & REPAIRS
Aluminum Wiring Repair-
-Methods - CPSC Meeting 9/28/95
Aluminum Wire Risk
Reduce the Risk
Repair Details
DIRECTORY OF ELECTRICIANS - Aluminum Wiring
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Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair

• Our recommended books about building design, inspection, and repair, and about indoor environment testing, diagnosis, and cleanup are at the InspectAPedia Bookstore.
• The Aluminum Wiring Information Website Aluminum Wiring Hazards and Repairs: in-depth info, photos, documents. Main Page.
• The Aluminum Electrical Wiring Hazard Explained (in the document you are presently viewing)
• How to Reduce the Risk in Buildings with Aluminum Electrical Wiring - Overview of Acceptable Repair Practices (in the document you are presently viewing)
• Aluminum Electrical Repair Method Details - "How to" details, how to identify, COPALUM repair, alternative repairs, history, products, research, source of special AMP TYCO COPALUM connectors & COPALUM Electricians (in the document you are presently viewing)
• COPALUM Electricians: Sources of TYCO COPALUM -Certified/Trained Aluminum Wire Repair Services (in the document you are presently viewing)
• Other Products, Ideal 65 Purple Twister (not recommended), & other Aluminum Wire Products/Articles (in the document you are presently viewing)
• The Aluminum Wiring Bibliography: extensive resources on Aluminum Wiring
• Aluminum Wire Failure Reports & Photos: Real life aluminum wiring field failure reports
• Reducing the Fire Hazards in Aluminum-Wired Homes, Jess Aronstein, Ph.D., This document answers most technical questions about the hazards and remedies of aluminum electrical wiring. Some of the sections of this very thorough document are listed below:
• Fire Hazards With Aluminum to Copper Twist-on Connectors & Acceptable Aluminum Wiring Repair Practices Color Photos, Current Issues. 9/28/95 CPSC Meeting Minutes
• "Is YOUR Aluminum Wiring Safe?" article discussing safety claims made by some people without looking at the wiring, J. Aronstein, 11/21/95
• "Repairing Aluminum Wiring," U.S. Consumer Product Safety Commission Publication CPSC#516 available online
• * Safety Hazards and Safe Inspection Procedures for Electrical and Home Inspectors at Residential Electric Panels
• Electrical Panels, How to Inspect in Buildings, safety for electrical inspectors, electrical panel, fusing, wiring defects, defective products. Inspection Class Presentation
• Electrical System & Wiring Hazard Inspection, Detection, Cause, Remedy, Prevention - Main Electrical Page
• Directory of Home Inspectors accessible via Internet
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