socalelect

Indeed harry yes indeed

socalelect

300.

jrannis

Generally, you will need one size up when using aluminum. The OD of compact strand aluminum is usually the same OD as the next size smaller copper.

250 aluminum is about the same size as 4/0 copper so, with very rare or maybe no exception, you can use the same size conduit.

The problem sometimes, due to an oversight in ordering gear, is that the lugs could be too small.
I have had jobs that could not be ordered with lugs larger than 500 when I was using 600AL and opted to use pin connectors. The conductors would have fit but I couldn't risk an overzealous inspector making me re terminate the entire job.

I'm not a big fan of copper now that I am getting older and even worse, having to buy it.

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"When a your only tool is a hammer, every problem looks like a nail"

Split Bolt

The bad reputation that aluminum conductors have comes not from feeders, but from branch circuits! During the Viet Nam war, copper was needed for the war effort, so they started making romex with aluminum conductors and wired a lot of houses with it. Bad news! Electricians weren't really schooled in how to use it, so they stripped it with their Kleins a lot, nicking the aluminum. They also didn't tighten connectors as tight as they should have or didn't use noalox. A lot of problems and fires have occurred as a result. Even devices that are rated for AL are supposed to have the terminals re-torqued every five years, so it is far better to change to copper with the $3 wirenuts (or other purple devices) than it is to use AL rated devices when replacing, IMHO. I use AL for the service. As for the large 50A+ loads in a new house, I have always used CU, but would really need to think about it now with the price difference! I remember reading an article in EC&M magazine back in the late '80s or early '90s about Stabiloy. It said that it was a better conductor than CU, but the NEC wouldn't recognize that and considers it the same as AL. (If my memory serves...I am getting old!) Did anybody else read that?

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"Golf is a good walk spoiled." -Mark Twain

cortez

In those days a lot of aluminum was connected with copper in wire nuts, and petroleum jelly was used as the anti-oxidant!!!

Coincidentally, the department of defense data reveals that it took 22,000 bullets to kill ONE Vietnamese combatant (and of course not all died from bullets but one must include mortar rounds, artillery rounds , mines, bombs ect., but that calculation was IF all enemy dead died from bullets it would come out to 22,000 bullets for each kill.

That's a lot of copper. All of our rounds were copper jacketed.

Lone Crapshooter

Origional aluminum pre 1973 is bad news.It was the same alloy that the power companies used (AA1350) and it worked good for them but they terminated in mechanical lugs or hypress lugs.

After 1973 they used a new alloy (AA8000) that its expansion and compression rate is close to that of copper . When properly sized and terninated it is just as good as copper. You must remember that the problem with aluminum is with the terminations not in the middle of the wire. Copper will fail in the same way if not properly terminated.

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Electrician licensing without continuing education is just another form of TAXATION

BBQ

Say what?

There was no copper shortage, it was just less expensive.

Split Bolt

Just going by what I've been told. I was just a kid and don't even remember the Vietnam war as a child!

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"Golf is a good walk spoiled." -Mark Twain

EBFD6

I was recently sent out to a job to help out for the day. This job was speced all AL feeders. My task for the day was to tie in the feeders that were already pulled at the various panels, sizes from 250's to 600's. As a service guy I don't get to do this very often, but I'm never real exited about it when I do. It's usually a much more difficult day than what I am used to doing service calls. This was my first time dealing with Al feeders in the commercial setting. I never want to deal with copper again. While AL has to be sized bigger for the same amperage as compared to CU, it is so much easier and lighter to work with. Easier to bend, stays where you put it, less stress on the cable ties when neatening up the panels. It was awesome!

BBQ

Cuts much easier as well.

Shockdoc

Aluminum cable will win the bid, I was noticing Lowes 2/0 cu SE cable @ $12.80 a foot. I can underbid all the loyal cu believers using AL 4/0 SE @ $5.00 a foot, using #2 AL for the GEC. I've only had one customer in 8 years realize I was using AL and paid extra to have copper run. I wish we could run AL for residential sub panels,AC compressors , ranges and dryers out here.

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All these liberal laws has turned me into a right wingnut..