0 gauge copper or aluminum?

Which one will let more current. I have always been under the impression copper is the best and nothing but, however now some people or telling me other wise. Thanks Guys.

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I have heard that using CCA(Copper Coated Aluminum) 0 Gauge is equivalent to using 2 Gauge true copper, Shame that I just got 50 feet of 0Ga CCA :-(

i am an idiot wrote:

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If you value your vehicle, use only copper wire.

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whats wrong with aluminum?

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Copper is the second least resistive material. Only silver possess a lower resistivity.
As a general rule, copper clad aluminum needs to be two gauge sizes larger to pass the same amount of current as copper.

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This information is provided only as a reference.
All circuits should be verified with a digital multi-meter prior to making any connections.

deeryders wrote:

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i am an idiot wrote:

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If you value your vehicle, use only copper wire.

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whats wrong with aluminum?

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I second the question... If the aluminum wire is adequately sized, then there is no difference between aluminum or copper. They're both perfectly usable conductors.

As long as the proper concessions are made, then I think that the "if you value your vehicle" statement is a little bit strong. :P

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

But you need a larger gauge of Al.

To answer the OP - copper. Just compare electrical conductivity tables.

Aluminium conducts more per weight, but not per gauge.
And aluminium fatigues & breaks easier, i trickier to terminate etc,


COPPER!

In general, don't use aluminum in low-voltage high-current applications.

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To lightly jack the OP's thread, Will it be ok to use the 50foot roll of 0Gauge CCA I have just purchased for running 1500-1600RMS off? I currently have 4Gauge copper run and it powers it nicely, I just wanted to put 0Gauge in for piece of mind.

In terms of conductivity:

Conductivity:
CCA = 2.74 Ohms cm (63)
Cu = 1.72 Ohms cm (100)
Resistance of CCA = 2.74/1.74 = 1.6 that of Cu. (CCA has 1.74/2.74 = 63% the conductivity of Cu.)

Dimensions:
0G = 8.25246 mmD = 53.5 mm2
4G = 5.18922mmD = 21.14 mm2    
0G has 53.5/21.14 = 2.53 times the area of 4G. (Conductivity is proportional to area.)


2.53 x .63 = 1.6 x the conductivity (of 0G CCA for 4G Cu).
(Or 1/1.6 = 0.63 the resistance of 4G Cu.)

So, electrically you are better off with the CCA.


Whether you should use CCA is another matter.

Electrically 0 ga CCA is better than 4 ga Cu. But if you want to replace 4 ga Cu with its equivalent CCA counterpart, follow along:

I will be using resistivity instead of conductivity, since the values are proportional,it will not make a difference.

Resistivity (ρ):
Cu = 5.61E-08 Ω-ft
CCA = 8.69E-08 Ω-ft

Following oldspark's logic, we have:
Resistivity of CCA = 8.69/5.61 = 1.55 of Cu (I dropped the exponents since they cancel out anyway.)
So,
CCA has 5.61/8.69 = 65% the resistivity of Cu

Dimensions:
2 ga = 6.54304 mmD = 33.61 mm2
4 ga = 5.18922mmD = 21.14 mm2

2 ga has 33.61 / 21.14 = 1.59 times the area of 4 ga

1.59 * 65% = 1.03

So, 2 ga CCA is 1.04 times the conductivity of 4 ga Cu. For 12V applications this is equivalent.

The resistance of 1000 ft of 4 ga Cu = 0.246 Ω
The resistance of 1000 ft of 2 ga CCA = 0.240 Ω

As oldspark has mentioned earlier, CCA is prone to fatigue fractures especially if it has been nicked and from flexing. Whenever possible it is best to use copper for automotive applications. If you must use CCA go at least 2 wire gauge sizes larger that what is recommended when using copper.

I have worked this out in the past and the resistance per 1000 ft is very close when comparing Cu with CCA that is 2 gauge sizes larger.
Maybe someday when I have a bit of time to kill when I get to 1000 posts under my belt, I'll do a write up on this to get my certification badge

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This information is provided only as a reference.
All circuits should be verified with a digital multi-meter prior to making any connections.

Our calcs should be the same. Resistivity is merely the inverse of conductivity.
We have the same conductivity/resistance ratio (5.61/8.69 = 64.5).
I presume my area calcs were wrong (pi R squared; R=D/2). I might recheck later in the year or decade....
But what an error - my 1.6x better makes the CCA enticing (though I reckon it's not enough to outweigh the complications - unless it's a race car...) whereas one wouldn't even consider doing it if there is only 4% difference.

All that's well and good, but I still believe - STRONGLY - that is proper concessions are made, i.e. upsizing the gauge appropriately for aluminum conductors, versus copper conductors, then there should be no difference between wires.

As long as the voltage drop is the same, regardless of the conductor, then explain to me WHY you still believe it's not a good thing to use aluminum in place of copper. Again, IF THE WIRE GAUGE IS APPROPRIATE FOR THE CURRENT REQUIREMENTS, THEN THERE IS NO DIFFERENCE, REGARDLESS OF THE CONDUCTOR.

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

The only problem using aluminum wire is that it is much more brittle than copper and it's more difficult to make good connections using it.  If you're a pro and know how to terminate it and properly support it fine, go for it.  But I for one do not recommend using Al wire in car audio applications.

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OK. I can accept that as a valid reason. I was not thinking of the work-hardening of vibrating metals. I also love your caveats! :P

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

haemphyst wrote:

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OK. I can accept that as a valid reason. I was not thinking of the work-hardening of vibrating metals. I also love your caveats! :P

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Yes, vibration is the enemy of aluminum wiring, especially in a vehicle.  My caveats are always the same: if you know what you're doing then do it.  If you don't, then don't. 

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Just installed 50 ft of 0Ga CCA wire last night, Running 1500RMS off it. Massive difference in sound quality over the 4Ga OFC I had in there, tho that's not to say 0 Ga OFC would not do better of course. I will let you guys no if any issues arise. Picked up IMC Audio 50Ft spool for $45Aud + Freight so I most certainly will not be complaining either way.

whats the difference from CCA wire and OFC wire

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MECP Certified
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CCA - Copper Clad Aluminum
OFC - Oxygen Free Copper

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."