Coppoer vs. Aluminum alloy conductor

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jkim780

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Because of copper price increase, I've got a lot of substitution request from contractors & mfgr. sales reps for copper conductors in favor of aluminum alloy conductors. What do you think of aluminum alloy conductors? Pros? Cons?
I can see that aluminum is lighter than copper, it has more flexibility and higher short-circuit withstand capability than copper. Is there any downside of using aluminum conductors?
 
This has been discussed here several times. The bottom line is both materials are perfectly suitable for use per the NEC. I see no safety issue with using either one, so it only comes down to cost and labor considerations.
 
The one downside of Aluminum is that is has only 61% of the conductivity of copper so when substituting AL for CU you will need larger or more conductors. This could require larger or more conduits. Depending on the labor costs for installation of conduit and wire the cheaper aluminum might not be cheaper after all.
 
I see a lot of the compact stuff that generally permits the same sized raceways. 4/0 compact AL looks identical to 2/0 CU supplying a 200A service.
 
bphgravity said:
I see a lot of the compact stuff that generally permits the same sized raceways. 4/0 compact AL looks identical to 2/0 CU supplying a 200A service.
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Yes this is true, but as you start to move up in conductor size and ampacity the issue becomes more prevalent. For example a feeder of 4-500kcmil Cu THHN conductors requires a 3" EMT conduit. An equivalent 4-750kcmil AL compact strand XHHW feeder would require a 3.5" EMT conduit.
 
Trevor,
For example a feeder of 4-500kcmil Cu THHN conductors requires a 3" EMT conduit. An equivalent 4-750kcmil AL compact strand XHHW feeder would require a 3.5" EMT conduit.
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Why did you change insulation type between the copper and the aluminum conductors. 4 THHN aluminum 750 kcmil compact strand fit in 3" EMT.
Don
 
don_resqcapt19 said:
Trevor,

Why did you change insulation type between the copper and the aluminum conductors. 4 THHN aluminum 750 kcmil compact strand fit in 3" EMT.
Don
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Mostly because of availability. A poor assumption on my part, but around here compact strand AL conductors are XHHW.
 
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