4/0 AWG welding cable versus Ancor marine grade tin coated

Wow, haven't seen the word "litz" since my audio engineering days......Was a bi#@$ to solder!

BiduleOhm said:

There's not skin effect with DC, only with AC, and it only matters if the frequency is higher than dozens of kHz (or a bit lower than that if we're talking about very large currents and very large wire, but that's not often you see that).

Also, even if there was the skin effect with DC you need isolated strands (it's called Litz wire) to have an impact, if they aren't then it's equivalent to a solid core conductor in regards to the skin effect.

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Really? My code instructor said the oxidation layer formed when the strands are made increases the amperage ability from skin effect on KV conductors. They even have compressed strands on the big stuff for feeding skyscrapers with KV service...
Or were you saying the skin effect on isolated strands was for dc?

kernel said:

He could just go parallel 750kcmil and sleep well at night

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... I actually have a 10ft chunk of that in the front seat of my truck...

As for the Skin Effect -- in EE School we were told that it happens in all wire/cable, both AC and DC. As the signal gets higher, the signal begins to move more to the outside of the conductor than the inside. We especially see this in RF signals (which I am a Goddess).

As for Skin Effect for what we are doing here -- for the most part -- I think for most of the ppl on this DIY forum, it will have virtually no concern and they will lose more amps in choosing or installing the wrong connectors then they will with over large stranded vs solid vs small stranded cable effects ... As long as they get as close to the right amperage as they can on cabling then i would be happy ...

IN REAL LIFE -- we see that they majority of Solar Systems not reaching their full potential due to folks trying to go cheap on their cables and undersizing ..

But thats just me ...

Supervstech said:

Really? My code instructor said the oxidation layer formed when the strands are made increases the amperage ability from skin effect on KV conductors.

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Which oxydation? the copper used in any decent wire is OFC and the insulation is gas-tight so only the ends are exposed to the oxygen of the air and can oxidize. That's why when you re-use an old wire (or use a wire stocked for a long time) it's a good practice to cut a few cm of the end.

Supervstech said:

They even have compressed strands on the big stuff for feeding skyscrapers with KV service...

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I don't know why they have compressed strands but certainly not for the skin effect.

Supervstech said:

Or were you saying the skin effect on isolated strands was for dc?

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There's no skin effect with DC. The skin effect is due to eddy currents and there's no eddy current if the EM field is not changing. The only way for the EM field to change is if the current changes and at DC the current doesn't change (at least not a lot, nor regularly nor rapidly, if the load is changing then there's some variations in the current of course). Please see: https://en.wikipedia.org/wiki/Skin_effect

Supervstech said:

... I actually have a 10ft chunk of that in the front seat of my truck...

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Oops, it was only 500Kcmil...
Here is a pic next to 4/0 cable also in my front seat...

I only use marine grade in marine applications. The extra cost of the tinning is not justified in non-marine applications.

I suppose I would consider it for a beach house, but even then it is questionable.

I do lots of work on boats. Countless times I've cut a piece of wire well away from the ends and there is corrosion on the copper. Only thing that stops this is tinned wire.

Somehow the corrosion gremlins are getting through the insulation feet from the ends pof the wire.

Rbertalotto said:

I do lots of work on boats. Countless times I've cut a piece of wire well away from the ends and there is corrosion on the copper. Only thing that stops this is tinned wire.

Somehow the corrosion gremlins are getting through the insulation feet from the ends pof the wire.

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Yup, tinned is critical in marine use... just not so much otherwise.

Supervstech said:

Yup, tinned is critical in marine use... just not so much otherwise.

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Tinned, heat shrink with glue and closed toe lugs.... totally sealed up.... and it can still get in.

I would have thought that a simple 'silver' washer between the post terminal and the cable or bar connection would eliminate all galvanic corrosion. If the heat shrink is applied right up over the lug shoulder, how does the atmospheric 'salt' get into the cables(im assuming the cables never get wet), plus, would these pouches that absorb all moisture in packaging etc(forget what they're called), if added to a well sealed battery containment area, could that not prevent corrosion over a long period. (I have no experience of marine instals, just wondering about possibilities)

Watch a video on aluminum reacting with gallium... it is NOWHERE as bad as that, but it shows you how the brine gas affects the metal...

Solarfun4jim said:

I would have thought that a simple 'silver' washer between the post terminal and the cable or bar connection would eliminate all galvanic corrosion. If the heat shrink is applied right up over the lug shoulder, how does the atmospheric 'salt' get into the cables(im assuming the cables never get wet), plus, would these pouches that absorb all moisture in packaging etc(forget what they're called), if added to a well sealed battery containment area, could that not prevent corrosion over a long period. (I have no experience of marine instals, just wondering about possibilities)

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It's one of the great mysteries... Salt air seems to be able to get past whatever you do to try to stop it.... It may have something to do with thermal expansion and contraction 'pumping' air in and out.

The desicant dryer packs can only help till they are saturated. On a boat that will probably be pretty quick.... but I like your thinking.

Yep, salt water is the most destructive (common) thing I ever saw. You can't stop it, just mitigate it.

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Ian said:

Is there anyone here that has experience using 4/0 awg ancor marine grade wire that can vouch for its flexibility compared to welding cable?
I may just go to a welding supply store and then to west marine to compare the two before making a decision.

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We have both Ancor marine-grade 4/0 and Cobra X-Flex 4/0 welding cable (though I don't think we list the welding cable, it's more for us to play with) and I can confirm that the welding cable is significantly more flexible than the Ancor.
That being said, the flexibility has nothing to do with strand count - the Cobra 4/0 welding cable has 2,107 strands of 30AWG pure copper, and the Ancor 4/0 marine-grade cable has 2,109 strands of 30AWG tinned copper. The increased flexibility of the welding cable is purely a matter of the jacket material. Welding cable jacket material is EPDM which is soft and flexible but not very abrasion-, chemical-, or UV-resistant. The Ancor cable is less flexible because the jacket is PVC for the requisite resistance to abrasion, chemicals, and UV exposure.

Rbertalotto said:

I do lots of work on boats. Countless times I've cut a piece of wire well away from the ends and there is corrosion on the copper. Only thing that stops this is tinned wire.

Somehow the corrosion gremlins are getting through the insulation feet from the ends of the wire.

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It's good to hear from some real world experience like this.

Justin Laureltec said:

We have both Ancor marine-grade 4/0 and Cobra X-Flex 4/0 welding cable (though I don't think we list the welding cable, it's more for us to play with) and I can confirm that the welding cable is significantly more flexible than the Ancor.
That being said, the flexibility has nothing to do with strand count - the Cobra 4/0 welding cable has 2,107 strands of 30AWG pure copper, and the Ancor 4/0 marine-grade cable has 2,109 strands of 30AWG tinned copper. The increased flexibility of the welding cable is purely a matter of the jacket material. Welding cable jacket material is EPDM which is soft and flexible but not very abrasion-, chemical-, or UV-resistant. The Ancor cable is less flexible because the jacket is PVC for the requisite resistance to abrasion, chemicals, and UV exposure.

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If you run it inside a braided cable jacket, well routed and secured on a car/truck. How much will the minor grease/oil effect EPDM?
I was going to ask TEMCo, but you're here on the forums.

Sgt Raven said:

If you run it inside a braided cable jacket, well routed and secured on a car/truck. How much will the minor grease/oil effect EPDM?
I was going to ask TEMCo, but you're here on the forums.

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You'll be fine running it that way; on a number of our RV and other mobile customers who aren't in coastal areas we'll regularly spec welding cable for ease of use.

Welding cable happens to be widely available. We cannot use it in pv systems as it does not usually have proper listing (nor marine/boating cable unless you are looking a litany of listings down the jacket) even though the material is quite useful as a conductor its main attributes of high power handling and primarily being flexible enough to accomplish its intended task, the jacket is soft, not delicate, but not armid either. It would nick or tear easier being pulled in some cases (dont make it hard to pull amd it wont be hard....) amd not pull well because of its texture and gription. Abrasion resistant enough for sure to sit in place. They get dragged across fabrication jungle, rough work tops, concrete, get walked on. If you are not going to do this to your cables, then;

All of the 105°C insulated cable of high purity and high strand count is generally suitable for battery cables. More flexible, more movement cycles before work hardening and heavy high temp insulation are the general requirements.

Alot of my small project stuff is wired thhn/mtw...... at small wire gauge size its flexible enough has a tough high temp jacket, but not a very thick one. If everything is pretty much going to sit and operate for years or is a temp in, i do it but cant suggest anyone else does.

Real battery grade cable and lugs are such a joy to work with and handle and especially when the size approaches anything over #2 bending gets to not be very fun. Tight confines a nightmare.

I use cobra or equivalent, there is some nice material out there if you look around or ask to examine them at supplier houses, some names are familliar and some not, even having seen alot of wire.

Quick cable parts and cable is good stuff, Magna Lugs!

Cobra....

All kinds of telecom and specialty suppliers, even southwire amd probably belden.

We used to get most cables made by marysville marine/inverter sales and service at tennessee but they have stopped providing the service.

The temco wire and cable we bought had the stuff, some welding amd some vw-1 pvc jacketed.
Neoprene can be from cake frosting to almost polyurethane in texture, not the hard glassy stuff, but like a good synthetic rubber, not nearly as hard as a pvc jacket.

In the end, you almost never go wrong with high quality insulated wire and cable, it is the thing that will make your project practical, safe and will outlast most every other component within the power system, rotten money swallowing boats not included....

Wire is permanent performance.