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?
On Wed, 14 Jun 2006 13:48:07 -0400, email@example.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.
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
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
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
besides at resale a home inspection, and nervous buyer.... equal pain
in you know what.
I see your point properly sized the voltage drop should be the
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
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.
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
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.
Doug Miller (alphageek at milmac dot com)
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...
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
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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