Ī home with aluminum wiring installed prior to the mid-1970s (as the stock of pre-1972 aluminum wire was permitted to be used up) likely has wire made with the older AA-1350 alloy that was developed for power transmission. Depending on the annealing grade, AA-8176 may elongate up to 30% with less springback effect and possesses a higher yield strength (19.8 ksi or 137 MPa, for a cold-worked AA-8076 wire).
#Aluminum to copper wire nuts series
Unlike the older AA-1350 alloy previously used, these AA-8000 series alloys also retain their tensile strength after the standard current cycle test or the current-cycle submersion test (CCST), as described in ANSI C119.4:2004. This alloy, along with AA-8030 (patented by Olin in 1973) and AA-8176 (patented by Southwire in 19), performs mechanically like copper. The first 8000 series electric conductor alloy, still widely used in some applications, was developed and patented in 1972 by Aluminum Company of America ( Alcoa). In the late 1960s problems and failures related to branch circuit connections for building wire made with the utility grade AA-1350 alloy aluminum began to surface, resulting in a re-evaluation of the use of that alloy for building wire and an identification of the need for newer alloys to produce aluminum building wire. In the early 1960s when there was a housing construction boom in North America and the price of copper spiked, aluminum building wire was manufactured using utility grade AA-1350 aluminum alloy in sizes small enough to be used for lower load branch circuits in homes. The lower weight of aluminum wires in particular makes these electrical conductors well suited for use in power distribution systems by electrical utilities, as supporting towers or structures only need to support half the weight of wires to carry the same current. USD $1/lb as of 2017 ), aluminum wires are one-sixth the cost of copper wire of the same conductivity. Since copper costs about three times as much as aluminum by weight (roughly US$3/lb vs. Accordingly, one pound of aluminum has the same current carrying capacity as two pounds of copper. Modern 500-kV overhead power lines used in an electrical power distribution system supplied by a utilityĪluminum alloys used for electrical conductors are only approximately 61% as conductive as copper of the same cross-section, but aluminum's density is 30.5% that of copper. While all devices were designed for aluminum during that era, this ended with unification in 1990 when standard Western European equipment became available and the national public owned enterprises ( Volkseigener Betrieb) went out of business. In communist former East Germany (GDR, 1945-1990), aluminum or Copper-clad aluminium wire (″AlCu-Kabel″) had to be used for wiring as copper was expensive import. Existing homes with this older aluminum wiring used in branch circuits present a potential fire hazard. Revised manufacturing standards for both the wire and the devices were developed to reduce the problems. Electrical devices (outlets, switches, lighting, fans, etc.) at the time were not designed with the particular properties of the aluminum wire being used in mind, and there were some issues related to the properties of the wire itself, making the installations with aluminum wire much more susceptible to problems. In North American residential construction, aluminum wire was used for wiring entire houses for a short time from the 1960s to the mid-1970s during a period of high copper prices. Aluminum wire in power transmission and distribution applications is still the preferred material today. It has cost and weight advantages over copper wires. Utility companies have used aluminum wire for electrical transmission in power grids since around the late 1800s to the early 1900s. Aluminum provides a better conductivity to weight ratio than copper, and therefore is also used for wiring power grids, including overhead power transmission lines and local power distribution lines, as well as for power wiring of some airplanes. 1970 East Berlin: workers in VEB Kabelwerk Oberspree producing aluminum wires with a SKET-built machineĪluminum building wiring is a type of electrical wiring for residential construction or houses that uses aluminum electrical conductors.
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