Aluminum or copper service wire?

Question

I'm running a 100 amp sub panel to my exterior building gonna be bout 60 70 feet. I know copper is better conductor but aluminum is much cheaper an is used often looking at 1-1-1-3 aluminum service cable

Answer 1

either or works just fine. aluminum for feeders is just fine. needs to be installed properly and up to code and that includes anti-oxidation compound on the terminations. check with your inspectors because you might need conduit runs as well for it.

Answer 2

Copper, Aluminium is adequate but tends to corrode especially in contact with copper. Bin there done that and took about 3 K to correct it, aluminium is still there but changes fixture et all still cost that much. Would have been thirty grand plus to take out all the aluminium , that was 30 years ago.

Answer 3

Copper is best and for that distance there will not be much saving to use aluminium

Answer 4

For that short a run, the use of aluminum is not worth the problems it will cause in installation and the increase cost of the connectors and treatments as far as I would do the work. I strongly urge to contact and employ a local qualified professional electrician to do the work. 100 foot of pvc conduit and the wire and the wages for a day work and the project is complete and done in a neat and workman like manner and you are ready to energize the outbuilding.

Answer 5

For service wire aluminum is standard in many places. As noted, it requires hardware suited for it. Here in Arizona I have never seen copper service wire.

Answer 6

You must use aluminum compatible panels at both ends

Answer 7

You may want to read this article:

http://www.aluminum.org/sites/default/files/Aluminum%20Building%20Wire%20Installation%20%26%20Terminations.pdf



If you're doing this on your own, I would suggest copper. You need to know what you are doing if using aluminum.

Answer 8

Contact your building department. Aluminum may not meet code. Even if it did, I think aluminum wiring is a very bad idea. Aluminum is prone to undetected installation errors that will result in building burning down.

Answer 9

Aluminum electrical wire has very high risk causing fire along the electrical joints that combine with copper parts. It called thermo effect and had been proved and this wire was abandoned from using in house wiring almost 40 years ago in north American countries. Also fire insurance would not cover this type defect in case fire.

Only one way to overcome it by using all parts are made with aluminum, like all the power sockets, power panel,fuse and breakers come with aluminum contacts and screws.

Answer 10

Aluminum is ok as long as you do it according to Code.

Answer 11

Use copper and keep it simple.

Answer 12

1350 alloy aluminum used before 1980 is a problem. Service feeders are now made from 8000 series aluminum alloy, no problem if terminated in terminals UL listed for Aluminum conductors.



From Southwire's website:



"Some buyers are still reluctant about aluminum building wire because of problems that occurred in the 1960s. At that time, materials costs were driving an industry-wide change from brass connector bodies and screws to steel. The change created temperature expansion problems with the electrical-conductor (EC) grade 1350 alloy then used in aluminum conductors. The actual problems lasted only a few years, and were resolved by the introduction of modern 8000 series aluminum conductor alloys."



Just a bit of sizing concern, some installation methods require rating according to the 60°F column of 310.15(b)(6), which is only rated for 85 amps.

Answer 13

I paid extra for copper THHN for my house and garage. I also used one size larger wire.



If a job is worth doing, it's worth doing right! Especially for yourself!



When I was a child, 50-60 years ago, the word "cheap" meant "inferior quality"! Now people are attracted to "cheapness"! Lol!



If your garage is connected to your house, it's a "branch circuit", for your information, not a Service Entrance. You had better make sure that you are using an acceptable cable. You DID talk to the building department of your city, right? And got an electrical permit? A homeowner's permit?



You don't mention the route that the cable will go between the buildings. Overhead? Underground?? What's the WHOLE story?



We use Noalox (anti-oxidation compound) on approved termination hardware and lugs here for aluminum SE cables.

Answer 14

Where do you live? In a lot of places, the building code doesn't allow for aluminum wiring anymore (and any aluminum wiring has to be properly remediated and inspected) as it can overheat and cause fires (though it's rare it did happen). This could also cause an issue with insurance as where I live buildings were built with aluminum wiring in the 70s and 80s but finding someone to insure a home with aluminum wiring is tricky and often more expensive.

You're probably better off spending the extra money on the copper wiring.