Al vs Cu.......are they equal?????? Which do you prefer and why?????

dionysius

Senior Member
Location
WA
Sorry if this has already been dealt with and if so cite the discussions.

My question is dealing with Industrial and Commercial only.

Includes buses, boards, panels, wiring, everything.

Where either Cu or Al are usable does anybody have any rationale for choosing one above the other, other that price and size?????

On average how much more expensive do you find Cu is percentage wise over Al ??????
 

dionysius

Senior Member
Location
WA
Weight advantage......

Weight advantage......

It takes only one pound of aluminum to equal the current-carrying capacity of two pounds of copper........

Most dislike of Alum stems from an old bad name from the 60s and 70s. Those issues no longer exist but tradition dies hard and morphs into fear and folklore.
 

JFletcher

Senior Member
Location
Williamsburg, VA
It takes only one pound of aluminum to equal the current-carrying capacity of two pounds of copper........

Most dislike of Alum stems from an old bad name from the 60s and 70s. Those issues no longer exist but tradition dies hard and morphs into fear and folklore
The majority of that Al still exists and is still problematic.

For commercial, Al is the way to go most of the time.

Are Al and Cu equal? no.
 
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petersonra

Senior Member
Location
Northern illinois
Occupation
engineer
The majority of that Al still exists and is still problematic.

For commercial, Al is the way to go most of the time.

Are Al and Cu equal? no.
Al and Cu are not equal. However, they can have very similar performance characteristics if applied correctly. Al is generally a more cost effective solution for larger cables, and is often easier to wrangle due to the lower weight for similar ampacity to copper.

As for being problematic, the only aluminum wiring that was ever actually a problem when installed according to manufacturer's instructions was residential wiring in smaller sizes (<10 ga.), usually to devices like outlets that did not have terminals that dealt with Al wire very well. The stuff that is still in service after all these years seems unlikely to just up and fail out of the blue.
 

big john

Senior Member
Location
Portland, ME
Let's put it this way: The vast majority of the conductors on the grid feeding your building are ACSR and ACSS.

If aluminum can be used reliably under harsh outdoor, high strain applications then it can darn sure be terminated reliably in indoor low-voltage gear.

I agree, a lot of concerns are just the aluminum boogeyman.
 

JoeyD74

Senior Member
Location
MA
I use aluminum for residential services but that's about it. Commercial stuff always get copper.
Im working in a building right now that the customer just had a thermo scan of all switch panels and disconnects, and they have a lot of hot spot issues that the report says need replacement. They are all aluminum feeds where the issues are and are all under 5 years old.
Im not sure yet if it's improper install as the connections are tight, I have to shut it down to see.
 

peter d

Senior Member
Location
New England
I use aluminum for residential services but that's about it. Commercial stuff always get copper.
Im working in a building right now that the customer just had a thermo scan of all switch panels and disconnects, and they have a lot of hot spot issues that the report says need replacement. They are all aluminum feeds where the issues are and are all under 5 years old.
Im not sure yet if it's improper install as the connections are tight, I have to shut it down to see.
I'd wager that not one of the connections was properly torqued. AL issues are always down to installation error or not using properly rated terminals (as in temperature rating.)
 

peter d

Senior Member
Location
New England
Let's put it this way: The vast majority of the conductors on the grid feeding your building are ACSR and ACSS.

If aluminum can be used reliably under harsh outdoor, high strain applications then it can darn sure be terminated reliably in indoor low-voltage gear.

I agree, a lot of concerns are just the aluminum boogeyman.
:thumbsup::thumbsup:
 

JoeyD74

Senior Member
Location
MA
That is interesting. Are you ever concerned that you will be bidding against someone who will use aluminum? Do the clients know how much more the copper will cost?
I always tell them the costs and specific material to be used and make them aware of aluminum wire and its cost savings. I just don't use it on commercial stuff.
 

cad99

Member
Location
ND
I don't have any personal problems with al. As far a feeders. Every large job cu wire is always speced. I believe it is a boilerplate specs but wish others would see the value in a proper al terminations.


Living the dream one nightmare at a time
 

JoeyD74

Senior Member
Location
MA
A friend of mine is electrical engineer and her company always specs copper and they go as far to inform customers they will not spec aluminum feeders in any projects based on problems in past jobs. This is all commercial projects though.
 

iwire

Moderator
Staff member
Location
Massachusetts
A friend of mine is electrical engineer and her company always specs copper and they go as far to inform customers they will not spec aluminum feeders in any projects based on problems in past jobs. This is all commercial projects though.
That makes me question their knowledge.
 

user 100

Senior Member
Location
texas
A friend of mine is electrical engineer and her company always specs copper and they go as far to inform customers they will not spec aluminum feeders in any projects based on problems in past jobs. This is all commercial projects though.
They probably believe it's cheaper to just put in copper than to have qualified personnel who can terminate aluminum appropriately or they are trying to make money off the old al scare. Al feeders are used all the time safely everywhere and it makes no sense to spend more money on a diffrent alloy that doesn't perform any better provided the cheaper one is put in right.

There is not a thing wrong w/ al as long as it's installed properly- no different than copper in that respect, cu is just more forgiving- if a lot of hacked up places wired/ w copper had been wired w/ al instead, they would have burned to the ground.
 
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Fulthrotl

~~Please excuse the mess. Sig under construction~~
They probably believe it's cheaper to just put in copper than to have qualified personnel who can terminate aluminum appropriately or they are trying to make money off the old al scare. Al feeders are used all the time safely everywhere and it makes no sense to spend more money on a diffrent alloy that doesn't perform any better provided the cheaper one is put in right.

There is not a thing wrong w/ al as long as it's installed properly- no different than copper in that respect, cu is just more forgiving- if a lot of hacked up places wired/ w copper had been wired w/ al instead, they would have burned to the ground.
Port of Long Beach used to have a policy of no aluminum wire permitted in the port.
here is how i did all the aluminum i used in the port. they were OK with it.
huge saving in material costs.... the Simpull in aluminum was 22% of copper at the time i bought.

hypress, either finger or lugs.

panduit 600 volt direct burial heat shrink tube.
slower than 3m cold forms, a ton cheaper.
direct burial, and submersible. lot of splices in substructures,
spent a wet winter submerged, and powered. they megger fine.

it was a lot of wire.. long pulls.

 

JoeyD74

Senior Member
Location
MA
They probably believe it's cheaper to just put in copper than to have qualified personnel who can terminate aluminum appropriately or they are trying to make money off the old al scare. Al feeders are used all the time safely everywhere and it makes no sense to spend more money on a diffrent alloy that doesn't perform any better provided the cheaper one is put in right.

There is not a thing wrong w/ al as long as it's installed properly- no different than copper in that respect, cu is just more forgiving- if a lot of hacked up places wired/ w copper had been wired w/ al instead, they would have burned to the ground.
Qualified personnel, Isn't that what we are as electricians?
 

JoeyD74

Senior Member
Location
MA
Port of Long Beach used to have a policy of no aluminum wire permitted in the port.
here is how i did all the aluminum i used in the port. they were OK with it.
huge saving in material costs.... the Simpull in aluminum was 22% of copper at the time i bought.

hypress, either finger or lugs.

panduit 600 volt direct burial heat shrink tube.
slower than 3m cold forms, a ton cheaper.
direct burial, and submersible. lot of splices in substructures,
spent a wet winter submerged, and powered. they megger fine.

it was a lot of wire.. long pulls.

Terminations would be my primary concern in aluminum feeds when under heavy load. The constant heat cycles will loosen the connection over time.
 
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