| This image (above) is a perfect example of the | | | | 4 way around the screw in a clockwise direction). |
| problems that are associated with Aluminum | | | | All connections should be tight. While repeated |
| wiring. Note letters A and B (the insulation jackets | | | | tightening of the screws can make the problem |
| are melted), which I will explain "Why" in the third | | | | worse, during the inspection it would pay off to |
| paragraph and C (mixing copper wiring with | | | | snug up each connection. |
| aluminum wiring on the same breaker). Aluminum | | | | {Note that stranded aluminum wiring is still often |
| wiring can not be mixed with copper wiring and | | | | used for the main service entrance cable at your |
| breakers can not be double tapped with two | | | | main panel. It should also be inspected.} |
| wires, unless designated by manufacturer and the | | | | |
| breaker connnection will contain a special clip for | | | | 3) The "push-in" terminals are an extreme hazard |
| double tapping. Aluminum wiring is very easy to | | | | with an aluminum wires. Any connections using the |
| identify due to it's obvious aluminum color. | | | | push-in terminals should be upgraded with the |
| Aluminum wiring is not to be confused with tin | | | | proper screw connections immediately. |
| coated copper which looks similar to aluminum | | | | |
| wiring but aluminum wiring has distinguishing | | | | 4) There should be no signs of overheating: |
| characteristics and is a solid conductor. | | | | darkened connections, melted insulation, or |
| I highly recommend that you do not use | | | | "baked" fixtures. Any such damage should be |
| aluminum wiring for any type of new installation. | | | | repaired by a licensed Electrician and the |
| But don't panic if your house does contain | | | | connection should be upgraded. |
| aluminum wiring. Aluminum wiring, when properly | | | | |
| installed, can be just | | | | 5) Connections between aluminum and copper |
| The main problem that exists with aluminum | | | | wire need to be handled specially. Current codes |
| wiring is a phenomenon known as "cold creep". | | | | require that the connectors used must be |
| When aluminum wiring warms up, it expands. | | | | specially marked for connecting aluminum to |
| When it cools down, it contracts. Unlike copper, | | | | copper. The NEC requires that the wire be |
| when aluminum goes through a number of warm | | | | connected together using special crimp devices, |
| cool cycles it loses a bit of it's tightness over time. | | | | with an anti-oxidant grease. The tools and |
| To make the problem worse, aluminum oxidizes | | | | materials for the latter are quite expensive - not |
| (or corrodes) when in contact with certain types | | | | practical to do it yourself unless you can rent the |
| of metal, so the resistance of the connection will | | | | tool. |
| go up. Which causes the aluminum wiring to heat | | | | {Note that regulations are changing rapidly in this |
| up and corrode/oxidize even more. Eventually the | | | | area. Suggest that you discuss any work with an |
| wire may start to become very hot and melt the | | | | Electrical inspector if you're going to do more than |
| insulation jacket (shown in the picture above) or | | | | one or two connections.} |
| the fixture that it's attached to, and possibly even | | | | |
| cause a fire. | | | | 6) Any non-rated receptacles can be connected |
| | | | to aluminum wiring by means of a short copper |
| Since people usually encounter aluminum wiring | | | | "pigtail". See #5 above. |
| when they move into a house that was built in | | | | |
| the 70's, I will cover the basic points of safe | | | | 7) Shows reasonable workmanship: neat wiring, |
| aluminum wiring. I suggest that, if you're | | | | properly stripped (not nicked) wire etc. |
| considering purchasing a home with aluminum | | | | |
| wiring or have discovered aluminum wiring after | | | | If, when considering purchasing a home, my |
| moving in, that you hire a licensed electrician to | | | | inspection of the exposed wiring (in your |
| inspect the wiring for the following: | | | | prospective home) shows no problems, you can |
| | | | | consider the wiring safe. If there are signs of |
| 1) Fixtures (eg: outlets and switches) directly | | | | electrical problems in many places (which will be |
| attached to aluminum wiring should be rated for it. | | | | noted on your home inspection report), I suggest |
| The device will be stamped with "Al/Cu" or "CO | | | | you consider a complete electrical inspection and |
| ALR". The latter supersedes the former, but both | | | | possibly upgrading all branch wiring throughout the |
| are completely safe. These fixtures are | | | | house. If the wrong receptacles are used, you |
| somewhat more expensive than the ordinary | | | | can replace them with the proper type, or have |
| fixtures. | | | | the Electrician use pigtails. Having this professionally |
| | | | | done by a licensed Electrician can run close to |
| 2) Wires should be properly connected (at least 3 | | | | $10.00 per receptacle/switch plus hourly labor. |