Price for copper wire to sub panel?

I am having a sub panel put into an attached garage. It will be fed from a 100 amp breaker in one of my house breaker panels. The wire run will be about 100 feet thru crawlspace and connecting breezeway.
The electrician wants to use AWG 2 aluminum wire. I prefer copper but know it is more expensive, especially with the recent copper price rises. He is going to check on what the additional cost will be to go to copper wire to the sub panel.
Can anyone provide me with a ballpark estimate of the cost of aluminum versus copper wire for a 100 amp run over 100 feet?
PaulF
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wrote:

He should be using #1al for 100a (NEC 310.16) or #2 cu (#3 cu if you can get it). There is really no compelling reason not to use aluminum if it is sized properly.
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On Wed, 14 Jun 2006 13:48:07 -0400, snipped-for-privacy@aol.com wrote:

Thanks. Maybe he is derating it for being a single dwelling. He says local code allows no 2 Al.
He got the prices -- No. 2, 4 wire Al wire is $1.32/ft and No. 4, 4 wire copper is $4.82/ft.
I decided to go Al.
PaulF
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When you say "wire" do you mean single conductor or are you referring to a cable? I just purchased #4 THHN copper today for 1.25 per foot, for cut wire. A roll of 500 ft was cheaper

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On Wed, 14 Jun 2006 16:18:53 -0400, "RBM" <rbm2(remove

I did mean "cable" when I said "wire". The price quoted was for the cable per foot.
PaulF
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Per NEC 310.16, with 90-deg C insulation (e.g. THHN) #2 Al is OK for 100A.
--
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Doug Miller (alphageek at milmac dot com)
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I would go with copper since its a one time expense. 100 feet of aluminimum will have a voltage drop, which YOU will pay for.
Personally I DONT care how much power the electrical supplier wastes but do care if I am paying for it....
Besides if your doing something power hungry that drop might matter....
if the sub panel feed is underground put it in conduit in case you ever decide to upgrade
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So will 100 feet of copper; so what? The voltage drop in a _properly_sized_ aluminum conductor is not significantly different from the voltage drop in a properly sized copper conductor.

You're paying for it anyway. You seem to be under the impression that copper wire doesn't cause voltage drop. That is not correct.

Utter nonsense.

First thing you've said in this post that makes sense.
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Doug Miller (alphageek at milmac dot com)
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For LOTS of devices the last few volts can be the difference between good operation and crappy use.
Lamps are like that, the last few volts is about 8% of the total britness. I used to fix copiers for a living, slight voltage drops caused major grief.
if your running a 120 volt moter it probably doesnt matter....
All conductors have voltage drop but alunimum is much worse than copper.
cheapinbg out on a one time expense is poor planning...
Been there done stuff like that:(
my 100 amp main service is a memorable stupid move.
Sometimes cheaper isnt better
the price difference is under 300 bucks, for a one time lifetime expense..
besides at resale a home inspection, and nervous buyer.... equal pain in you know what.
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I'm missing your point. When aluminum is used, the conductor size is increased from what it would be if copper was used, so there shouldn't be any significant difference in voltage drop

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I see your point properly sized the voltage drop should be the same......
my point is aluminum wire may be a issue at resale
copper isnt that much more, a few hundred on a fairly big job. If your paying to have it done the install labor is likely a large cost, which makes a few hundred as a percentage of the job, a minor issue...
I guess I just dont like anything but copper for wiring, its the ideal product.
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wrote:

Only if the home inspector is a moron. There is absolutely nothing wrong with aluminum if it is used in aluminum lugs, whitch they all are these days in these sizes. The aluminum hysteria was caused by a different alloy in a totally different application using binding screws, not lugs.
Personally I bet they start trying to sell us aluminum for 15/20a branch circuits again if copper prices keep rising. That was how we got the stuff the first time.
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I certainly prefer to use copper, although I've never had problems with aluminum in larger sizes. Right now with copper prices up around 600%, there is a huge difference in price between the two. If the price doesn't come down, I think alot of people are going to suddenly see aluminum in a different light

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For the same size conductor, yes -- but you _don't_use_ the same size conductors with aluminum that you do with copper.
The difference in voltage drop in a copper conductor sized for 100A, and an aluminum conductor sized for 100A, is negligible.
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Doug Miller (alphageek at milmac dot com)
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On Wed, 14 Jun 2006 23:36:50 GMT, snipped-for-privacy@milmac.com (Doug Miller) wrote:

...but the lugs are only rated 75c
You also can't use the "dwelling" exception 310.15(B)(6) if this is not the sole feeder/service to the home. Sub-panels have to use 310.16
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The world is filled with moron home inspectors:(
Example I sold a home lerss than 2 years ago. The first buyer backed out after the inspection commenting your home is in terrible shape:(
This based on the inspection...
Written up:
No GFCI on sump pump in garage:( The home is 50 years old. GFCIs diodnt exist when it was built. After buyer #1 backed out I installed GFCI...
Next buyers inspector. You have GFCI on sump pump VERY BAD!
Even the home inspectors couldnt agree....
so anything peculiar will bring questions and hassles............
Most people just know anything but copper is bad...
Even if it passes inspection that nagging doubt may cost you a buyer or some bucks
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snipped-for-privacy@aol.com wrote:

One of my pet peeves about giving someone a little authority and they make their own rules.
Unless specifically mandated to prohibit use inspections should be according to the rules in effect at time of construction or installation.

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Home inspectors want old houses built to 2010 standards, which is impossible...
Its a dis service to everyone!
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Home inspectors want old houses built to 2010 standards, which is impossible...
Its a dis service to everyone!
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