# what is the real difference in pwr wire cca vs ofc vs copper weld



## corcraft

I am in the market for some 1/0 cable and before I started looking I thought that every wire was the same. What is the real difference? I want to use black so welding cable is ok with me but what is the difference in that vs ofc? Also, I was getting ready to click the "buy now" button on ebay for a roll of metra install bay but it is cca and I have read where 1/0 cca is no better than 4g ofc so it gets a little confusing on what to buy. I don't want to spend allot of money on pwr wire but I will be running 180- 200 amps of current so I need something that will be sufficient for that amount and not stiff as a board. Will the cca do? Will welding cable work as good as ofc? Or do I need ofc?


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## corcraft

anyone?


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## Wheres The Butta

I'm curious to see what people think. The conventional wisdom that I'm familiar with is that 100% OFC is best, but probably unnecessary outside of competition setups.


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## 240sxguy

Honestly dude, I am not so hung up on the OFC wire for power/ground. I understand the purpose of it but don't feel that the additional cost etc.. would be warranted. 

Plus, welding wire is really easy to run due to its flexibility.


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## corcraft

240sxguy said:


> Honestly dude, I am not so hung up on the OFC wire for power/ground. I understand the purpose of it but don't feel that the additional cost etc.. would be warranted.
> 
> Plus, welding wire is really easy to run due to its flexibility.



So what is the purpose of it over welding cable?

Is CCA wire that bad? If the myth is true that it's about the same as 4g ofc then what is the pupose of it being made? Isn't 4g ofc cheaper and easier to run? Or is that just a myth? 

I want the wire to be safe with 180amps and not cause a current drop and the cheapest that will do that for me. Is cca out of the question? A 50' roll of metra install bay cca is only $60. A 50' roll of knu is like $85 but it's still cca and then a 50' roll of weld wire is $100+.

Thanks for the replies!


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## mattyjman

http://www.diymobileaudio.com/forum...9-copper-clad-vs-real-copper-power-wires.html

try the search button... it works.


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## corcraft

.......... well ya can't search ofc or cca and not many people refer to cca as copper clad aluminum....... and if I would have searched titles for copper clad aluminum then that post that you attached wouldn't have came up either because it just says copper clad. Therefor I made the executive decision to ask myself but thanks for the attachment!


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## mattyjman

sorry, i wouldn't normally do this.. but not searching and then making an excuse not to that's not even valid... meh... all i suggested is that the search feature works... look below.


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## corcraft

I just read the attachment and allot of good info there, Thanks! Basicly you need to get 1 gauge bigger in cca so 1/0g cca = 2g ofc.

Now that we got an answer to that what makes ofc better than pure copper welding cable other than the pretty colors?


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## corcraft

thanks but ya still cant search cca or ofc and nor would the proper name for each have worked by searching title like I said. You started that thread (which has some good info) so of coarse you knew how to search for it. Thanks!


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## cubdenno

Welding cable is usually OFC. otherwise, unless the welding wire is listed as not being copper, then it totally depends on what you are wanting to do. generally car audio power wire is more flexible then welding cable due to the jacket.


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## corcraft

Ahhhh, thanks! That is exactly what I wanted to know.


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## 240sxguy

cubdenno said:


> Welding cable is usually OFC. otherwise, unless the welding wire is listed as not being copper, then it totally depends on what you are wanting to do. generally car audio power wire is more flexible then welding cable due to the jacket.


I have found the opposite to be the case, so OP check out what you are buying.


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## chad

cubdenno said:


> Welding cable is usually OFC. otherwise, unless the welding wire is listed as not being copper, then it totally depends on what you are wanting to do. generally car audio power wire is more flexible then welding cable due to the jacket.


You work in the steel industry and are still using welding cable from the 50's?

The **** with the inner Teflon jacket just rocks. II used to buy Harris Welco-Flex but the rural king house stuff is comparable.


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## arw01

When I built my shop, I had to go to 000 aluminum wire to be the equivalent of 0 gauge copper. Eventually CCA will also oxidize which can affect your current flow. I would go copper and only grimace once on the price.


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## danssoslow

One neg to aluminum, in houses and commercial applications, is its low elastic modulus. Over time, it will loose tension under a lug or set screw. This will not only cause problems that can be hard to trace, but potentially a fire hazard.


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## chad

arw01 said:


> When I built my shop, I had to go to 000 aluminum wire to be the equivalent of 0 gauge copper. Eventually CCA will also oxidize which can affect your current flow. I would go copper and only grimace once on the price.


Noalox FTMFW.

But I agree, I'm a fan of copper.


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## Oliver

Welding & Battery Cable

Coarse Strand Battery Cable

Coarse Wire Cable usually used in Cars and other applications that do not require the cable to be Flexible.


Fine Strand Welding Cable

Fine Stand Welding Cable is usually used on Electric Vehicles and other Mobil Electric Projects.


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## sqshoestring

The fine stranded on the welders I've used, and that is all I have ever seen on a welder (MIG usually), is like hair and far more limp than car wire. I'd guess part of this is because the casing is pretty thin on welding cable, but I can assure you it is durable and fairly fire proof lol. I have alum for the main wire into my house, thankfully nothing else. It is showing a ground fault, so I have to turn off all my power and crank down the lugs. That usually means the ground (neutral on the 220) is floating some. I have some special electrical spray to put on the lugs, I might as well pull the meter and do all of them what a pita. The previous owner told me he had to tighten them before. It is coarse wire and rock hard, you would never want to install that crap in a car, I would never put coarse copper in a car either at least the stuff used for houses. You can make coat hooks from it.

There are very few things I'd use aluminum wire for and in a car is not one of them, due to daily movement of a car. My rule is buy the cheapest copper you can find that fits the use be it looks or performance, copper is copper in most cases. I used bulk lamp cord for home and car speakers for years for hidden things, that stuff is really tough and works great long as the size is right for the use.


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## dstaley

The electrical conductivity of aluminum is 62% that of copper (google it if you don't believe me). Therefore, you will have to increase two AWG wire sizes to have the same resistance per foot of aluminum wire as you would have with a given size of copper wire (4 AWG vs. 2 AWG, etc).

I would just get the cable size you need in copper so as to avoid many of the corrosion and conductivity issues you have.

By the way, the conductivity of iron is far less than even that of aluminum- about 18% that of annealed copper. 

If you are really running over 100A, it would be wise to run a separate large gage copper negative wire as your losses through the chassis (especially sheetmetal only as in modern unibody design cars) become significant. Even if you don't follow this advice, make sure the ground cable/strap between your engine block and whatever part of the chassis you are using as ground (frame if a full frame vehicle or body if a unibody) is up to the task, as are the fasteners on either end of the strap. A large sheetmetal screw is NOT sufficient to carry 100+ amperes from the engine block/alternator to the body where your amplifiers are connected!


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## MTU_Husky

Also, copper is copper for your purposes, OFC vs non OFC copper will do the same things. You have to get up into high frequencies, much higher than 20khz even for OFC to be needed.


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## cubdenno

dstaley said:


> The electrical conductivity of aluminum is 62% that of copper (google it if you don't believe me). Therefore, you will have to increase two AWG wire sizes to have the same resistance per foot of aluminum wire as you would have with a given size of copper wire (4 AWG vs. 2 AWG, etc).
> 
> I would just get the cable size you need in copper so as to avoid many of the corrosion and conductivity issues you have.
> 
> By the way, the conductivity of iron is far less than even that of aluminum- about 18% that of annealed copper.
> 
> If you are really running over 100A, it would be wise to run a separate large gage copper negative wire as your losses through the chassis (especially sheetmetal only as in modern unibody design cars) become significant. Even if you don't follow this advice, make sure the ground cable/strap between your engine block and whatever part of the chassis you are using as ground (frame if a full frame vehicle or body if a unibody) is up to the task, as are the fasteners on either end of the strap. A large sheetmetal screw is NOT sufficient to carry 100+ amperes from the engine block/alternator to the body where your amplifiers are connected!


Very well stated. Glad you posted this. Most people do not get this.


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## ChrisB

That is what I did in my sister's vehicle by running 4 gauge CCA instead of 8 gauge copper. Her amplifier only had 40 amps of fusing, but I figured it was better to be safe than sorry just in case I decided to upgrade her to a pair of smaller amps later. Also, the local Best Buy wanted in the neighborhood of $160 for their Kicker 8 gauge wiring kit whereas KnuKonceptz had the 4 Gauge CCA kit for less than $30 shipped at the time.

Don't get me wrong, I do like Kicker Hyperflex and have a 4 gauge Hyperflex kit in my wife's vehicle. I just didn't think it was worth spending that kind of coin on a college student's system. Furthermore, she's my sister and I know that she would NOT pull the wire prior to getting rid of her vehicle.


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## Phreaxer

this thread has made me decide to pull out the wire I have had sitting in a container in my garage for the last 5 years waiting for me to get another install put together and see how it's held up. Some stinger 12ga speaker wire, and mainly welding cable (2 gauge)....  If it's pic worthy, I'll post them.


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## andrave

cca is lighter, cheaper, and ok for lots of people. I don't like it though. I'd compare it to using boss audio camps. 90% of the public wouldn't ever know. But I know they suck, so I just can't.


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## chad

If you are dumping enough stuff in your trunk that will require you to think about the weight of the power cable.. Then the weight of your power cable is the least of your worries.


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## adrenalinejunkie

Just go with the OFC stuff, either way we spend a lot of money on this hobby.


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## Hillbilly SQ

Another vote for pure copper. It's all I use. My main power is on its 3rd truck and it's in just as good of shape as it was the day I bought it. Install and forget it is the way to go. A great source for speakerwire is the 4-way flat trailer wire. The copper seems to be pure and it's tough as nails for its size. Perfect for tight places and 99% of the systems out there and on this forum don't need more than 16g for speakers and subs.


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## adrenalinejunkie

I invest my money on decent equipment so why go with CCA when OFC is known to carry more current and have less voltage drop. I recently installed 1/0 gauge kicker flex ofc wire , go big or go home.


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## upgrayedd

I love the welding cable. The strands are fine, the jacket is super flexible and the price is not bad.


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## t3sn4f2

dstaley said:


> The electrical conductivity of aluminum is 62% that of copper (google it if you don't believe me). Therefore, you will have to increase two AWG wire sizes to have the same resistance per foot of aluminum wire as you would have with a given size of copper wire (4 AWG vs. 2 AWG, etc).
> 
> I would just get the cable size you need in copper so as to avoid many of the corrosion and conductivity issues you have.
> 
> By the way, the conductivity of iron is far less than even that of aluminum- about 18% that of annealed copper.
> 
> If you are really running over 100A, it would be wise to run a separate large gage copper negative wire as *your losses through the chassis (especially sheetmetal only as in modern unibody design cars) become significant*. Even if you don't follow this advice, make sure the ground cable/strap between your engine block and whatever part of the chassis you are using as ground (frame if a full frame vehicle or body if a unibody) is up to the task, as are the fasteners on either end of the strap. A large sheetmetal screw is NOT sufficient to carry 100+ amperes from the engine block/alternator to the body where your amplifiers are connected!


Nope, especially on the sheet metal even.

First, we can assume a few things..... 

One that we have a continuous floor pan to bolt the ground to on both ends to (IE the firewall on the engine bay side and the rear trunk/hatch area). And if not it still does not matter since the many spot welds or welds can easily carry the current without loss to the following pan. 

Next is that the ground lug will not be bolted near the perimeter of said floor pan so there isn't a current saturation from the reduced area that comes from mounting too close to an edge (IE bolting a lug to the corner of a square sheet of metal is not the same as bolting it away a few inches from all edges since electricity flows into the metal in all directions and there is less cross sectional area and surface area immediately around those locations, especially a corner). Follow me? Hope so.

Having that established. We know that copper is 5 times more conductive than the least conductive steel sheet metal. But, a floor pan has a cross sectional area (ie "gauge") that is 50 times greater than a 0 gauge wire.

Copper:

0 gauge cross sectional area = .08215 square inches or equal to a 5/16" x 5/16" solid copper rod.

Steel:

An 18 gauge steel floor pan's cross sectional area is = 4 square inches or equal to .0478" thick x 84" wide piece which is typical of any car. 

That's 50 times greater than the wire.

Not only is the cross sectional area much greater but the cross section perimeter is also much larger. Which is an important factor for conduction since electrons flow on the surface of a material. Two dimensionally speaking the floor pan has 168 inches of surface (under and over the pan combined) and a wire only has the sum of the circumference of each individual strand minus where each strand touches another since that would not be an open face but an inner part).


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## gstokes

corcraft said:


> I just read the attachment and allot of good info there, Thanks! Basicly you need to get 1 gauge bigger in cca so 1/0g cca = 2g ofc.
> 
> Now that we got an answer to that what makes ofc better than pure copper welding cable other than the pretty colors?


Pure copper cable such as welding cable is superior to CCA, the specific resistance of copper is almost 2x better than aluminum, copper clad aluminum cable is not a good choice for audio cable.
On a different note you should be aware of the "skin effect" that happens in audio cables and pure copper cables such as welding cables would have horrible skin effect because the strands are all bundled together and have little to no twist, google "litz wire" and DIY, cheers..


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## mathematics

gstokes said:


> Pure copper cable such as welding cable is superior to CCA, the specific resistance of copper is almost 2x better than aluminum, copper clad aluminum cable is not a good choice for audio cable.
> On a different note you should be aware of the "skin effect" that happens in audio cables and pure copper cables such as welding cables would have horrible skin effect because the strands are all bundled together and have little to no twist, google "litz wire" and DIY, cheers..



skin effect only applies to AC, not DC.


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## minbari

gstokes said:


> Pure copper cable such as welding cable is superior to CCA, the specific resistance of copper is almost 2x better than aluminum, copper clad aluminum cable is not a good choice for audio cable.
> On a different note you should be aware of the "skin effect" that happens in audio cables and pure copper cables such as welding cables would have horrible skin effect because the strands are all bundled together and have little to no twist, google "litz wire" and DIY, cheers..


as above said. Skin effect doesnt happen at DC voltage, only AC. and even then it will occur at AC freq WELL above audio freq.

As for CCA, 2x is pushing it a bit much. 

resistivity of Copper is 1.68 ohms x 10-8
resistivity of pure aluminum is 2.65 ohms x 10-8

not quite 2x and since CCA does have some copper content, no where near 2x. At any rate, you gauge wire based on demand not based on resistivity anyway. CCA will require a larger gauge wire than OFC for the same application, I dont think anyone is disputing that.


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## CrossFired

Cant really speak on CCA, as I've never used it. But I know there's 3 grades of welding cable, and the high grade is about 5 x the cost of the low grade. I've used the high grade and low grade for welding, and there is a noticeable difference between the two.


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## Hanatsu

mathematics said:


> skin effect only applies to AC, not DC.


... and generally not an issue with audio equipment in general. Skin effect is a problem in RF land.


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## Cowkilla

240sxguy said:


> I have found the opposite to be the case, so OP check out what you are buying.


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## Cowkilla

Most welding cable is not ofc, stop spreading bad information


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