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Today, I melted some metals for the first time, including some aluminum cans and aluminum parts from my drying machine. I was thrilled to create ingots from them. However, when I tried to make a copper ingot from wires taken from an electric motor, I realized that the resulting ingot was pure aluminum! I was puzzled and investigated the wires more closely. It appears that the core of the wire is grey, while the outside looks like copper. The color on the outside is identical to that of a normal copper wire. The electric motor is from a 'Whirlpool Duet Sport' dryer. I'm wondering if it's a new industry practice to make aluminum wire look like copper, and if it's illegal to do so.

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    $\begingroup$ It's illegal to sell copper-plated aluminum as copper, but when you are buying a dryer, you are buying a dryer, not copper. en.wikipedia.org/wiki/Copper-clad_aluminium_wire $\endgroup$
    – DKNguyen
    Apr 17, 2023 at 1:03
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    $\begingroup$ it's probably not copper ... it is enamel insulation $\endgroup$
    – jsotola
    Apr 17, 2023 at 3:05
  • $\begingroup$ Installation and maintenance of aluminum wiring is a little tricky, so it's no longer used for things like household wiring. But a home handyman won't usually deal with motor windings, so (assuming they're built properly) they're quite safe. Laws for the sake of safety are easy to imagine, but with no obvious effect on safety, it's hard to imagine justification for a law saying insulation must make it obvious what material is used for the conductor. $\endgroup$ Apr 17, 2023 at 16:16
  • $\begingroup$ One other choice related is down to the strength of aluminium cf that of copper and the forces based on the rotational speeds. $\endgroup$
    – Solar Mike
    Apr 19, 2023 at 7:03

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All wires used to wind coils for motors must be insulated so adjacent loops of wire do not short-circuit themselves. For some reason the most common form of wire insulation enamel is orange/red in color (this has been true for over 50 years), which coincidentally gives it the appearance of copper wire.

That said, I had no idea that anyone was using aluminum wire for motor windings. Every motor I have ever taken apart used enameled copper wire.

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  • $\begingroup$ Exactly, It was a huge surprise for me to see that it wasn't copper but aluminium witht the enamel insulation. It feels like a scam since, it's the motor that broke. well ! The more you know. $\endgroup$ Apr 17, 2023 at 12:53
  • $\begingroup$ How can it possibly be a scam? Just because you were disappointed doesn't mean that someone made any unmet promises. Copper's expensive and mining it is a big hit on the environment. If the motors in my new appliances have aluminum wire -- great! $\endgroup$
    – TimWescott
    Apr 18, 2023 at 2:01
  • $\begingroup$ @TimWescott it feel like a scam since it is less of quality but hey who am I to judge. I found this great lecture talking about it. fisherpaykeltechnologies.com/knowledge-hub/… $\endgroup$ Apr 19, 2023 at 15:26
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Not illegal. Aluminium is lighter and almost as conductive as copper. Makes economic sense to use aluminium for lighter and cheaper motors.

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