Copper vs aluminum on large jobs

[electrofelon]

I almost posted this in an existing thread but didn't want to hijack it so I thought I would start a new one. On jobs that have significant amounts of large conductors, who exactly is making the decision of copper vs aluminum conductors? Obviously it's not the same answer every time, but what is your experience on how this works. Does the owner want copper and willing to pay five times the material cost? Is it a government project or large corporate entity where they don't care? Does the engineer/person who designed it just default to copper without giving the person writing the checks a choice? With AL of course you have to go up one physical size which may incur a larger pipe size which would be more material cost and a little more labor, but I assume this is relatively insignificant compared to the conductor cost savings or no? On these big jobs, approximately what is the percentage split you are seeing between aluminum and copper usage?

 

[infinity]

For the past 35 years for us it has always been copper first. In the past 3 years we're starting to see designs where aluminum is being substituted for copper. IMO larger aluminum conductors like 600 and 750 kcmil with crimp on terminals are better than copper even when the copper uses less labor intensive mechanical lugs because it's so much easier to work with.

 

[Hv&Lv]

Used to do some work for and around state agencies while in my present job. The STATE requirements were for copper only. No aluminum at all.
makes sense to me.. the state agencies aren't spending their own money.

 

[infinity]

Aluminum conductors still suffer from the stigma of being less reliable than copper. If you tell the designers I want the best possible materials regardless of cost then copper wins every time. In my experience most of the failures with aluminum stem from the terminations. If you can mitigate those failures with crimp terminals, anti-ox paste and proper torqueing then aluminum is certainly better in large conductor sizes if you want to save money.

 

[electrofelon]

So what triggers "value engineering" (which I assume switching from copper to aluminum would fall under). Is there pushback and thus a reevaluation from the person paying the bills? Does the electrical contractor just suggest ways to save money out of the blue?

 

[infinity]

So what triggers "value engineering" (which I assume switching from copper to aluminum would fall under). Is there pushback and thus a reevaluation from the person paying the bills? Does the electrical contractor just suggest ways to save money out of the bills?

If the system is designed for copper we may suggest to the building owner to use aluminum as part of value engineering. They will often ask us to look at the engineering design and see if we can value engineer that design to save them money by making suggestions that would still be code compliant.

One big one that I see is using the EMT raceways as the EGC. The last 3 large projects that we've done did not use a wire type EGC in the EMT as a cost savings. The original EGC's were removed as part of value engineering. Same thing with switching from copper to aluminum.

 

[cdslotz]

So what triggers "value engineering" (which I assume switching from copper to aluminum would fall under). Is there pushback and thus a reevaluation from the person paying the bills? Does the electrical contractor just suggest ways to save money out of the blue?

Yes. The EE will always specify copper first. If you are awarded the job and the owner is requesting VE, then you submit that savings. If approved, the EE is off the hook for any liability (same with any VE item the owner approves)
You can also submit VE items "below the line" at bid time....the "line" meaning as specified

 

[electrofelon]

You can also submit VE items "below the line" at bid time....the "line" meaning as specified

Is that pretty common to submit a bid, but with it say something like, "I can install aluminum conductors instead and it will be $10,000 less...."?

Just curious about all this, I do all my own design, fortunately, and rarely have to install someone else's.

 

[infinity]

Just curious about all this, I do all my own design, fortunately, and rarely have to install someone else's.

If you're doing your own design what parameters are you using to determine what to choose? For example do you always default to copper conductors, EGC's in metal raceways, etc. or just the lowest possible price?

 

[curt swartz]

Pricing in your area must be very different than around me if Copper is 5 time the price of Aluminum. In the past couple years the price of Aluminum wire has gone up substantially more than copper. I have price compared a few smaller feeders recently and the prices were almost the same including bumping the raceway size up for the AL

 

[Charged]

Mist of the time as a designer I start with copper first to leave some places to VE in the electrical package so they don’t just gut the lighting package or something , which they will anyways , but if the project as a whole is over budget , they will look for every trade to offer something regardless if it was over designed or not , so leaving the copper in at start is a good place to offer something when the VE process begins

 

[electrofelon]

If you're doing your own design what parameters are you using to determine what to choose? For example do you always default to copper conductors, EGC's in metal raceways, etc. or just the lowest possible price?

I guess I would say I design as if I were paying for it which is generally lowest cost - at least for things that I don't think offer any significant advantage, like copper conductors, wire egc's, circuits with dedicated neutrals.... Of course, like everyone, I have my opinion on certain things that are worth spending a little more on, that I won't even give the client the option for, such as I won't backstab in residential and I'll supply mid to high grade devices in commercial.

 

[electrofelon]

Pricing in your area must be very different than around me if Copper is 5 time the price of Aluminum. In the past couple years the price of Aluminum wire has gone up substantially more than copper. I have price compared a few smaller feeders recently and the prices were almost the same including bumping the raceway size up for the AL

Perhaps I was exaggerating a little bit I think I recently ran some numbers and it was four times as much, not including increase in a pipe size. I find rarely does the pipe size need to be increased as I can reduce the neutral a bit if needed. I also have been frequently running AL MC feeder cables instead of pipe and wire. I seem to remember you mentioning this recently and recalling that you were paying a lot more than I was for aluminum conductors.

 

[curt swartz]

Just looked at one of my suppliers. These are the current prices. My sales person might be able to adjust some buy they would still keep the same proportions.

#3 CU = $1.49
#1 AL = $1.15

3/0 CU = $3.87
250 AL = $2.57

600 CU = $14.11
1000 AL = $10.24 (They don't stock 900)

 

[curt swartz]

About 2 years ago I was paying $.65 for 6/3 (6666) AL SER cable. 6/3 NMB was ~$5. Now the SER is $2.16 and the copper is $3.31.

 

[AC\DC]

ya everyone jumped to aluminum, so get charged more.
You still have to account that the ser can be used in coulomb 75% vs 60% so it’s still a large saving.

 

[LT Sparky]

On a project now that the EE said it was ok to run AL from the transformer to the service disconnect. But everything load side of that he wanted Cu.

 

[electrofelon]

Just looked at one of my suppliers. These are the current prices. My sales person might be able to adjust some buy they would still keep the same proportions.

#3 CU = $1.49
#1 AL = $1.15

3/0 CU = $3.87
250 AL = $2.57

600 CU = $14.11
1000 AL = $10.24 (They don't stock 900)

Yeah Curt those number are not as diiferent as they used to be, maybe I am behind the times a bit. I guess its been a little while since I purchased wire. On AUG 15th I got a bunch of 500 XHHW AL and it was $4.16, and I remember thinking that was high, but I didnt price copper. two weeks ago I did get some #1-4+G AL MC and I nearly had a stroke it was $7/foot, about the price 250-4 used to be. #1 single conductor was $1.03. 4/0 URD is now $4.60 from one place, I remeber it was like $1.86 forever - up until a year a go anyway.

 

[Little Bill]

About 2 years ago I was paying $.65 for 6/3 (6666) AL SER cable. 6/3 NMB was ~$5. Now the SER is $2.16 and the copper is $3.31.

Not my job, but one of my friends was pricing for a job and found he could get #6/3 NM CU cheaper than #4 SER.
My take on this is everyone was jumping off the copper band wagon and buying Al. Now the Al industry has adjusted their price to near copper since the demand is there. I don't know of, or heard of, any reason for Al to have made such a jump. I think it is just "because they can"!

 

[ron]

We typically talk to the client during the design to discuss options. If we show CU only on the drawings, the Elec Contractor just has to submit a substitution request with a reasonable credit for AL, and the client bites. Of course the credit is only a fraction of the real savings, but it is a way that many projects change from CU to AL.