[edit] Grounding Wire Discussion (was: Insane Stats on Knukonceptz Kolossus Wire)

[Robert T]

I'm almost done with a slideout battery/inverter install in my RV, one of my last components to acquire is my ground wire. It will pass under the slideout and be attached to the frame (7' total) so it must be durable, very flexible, and tinned. At first I was looking for Class M wire but I can't find it tinned. Then I stumbled on this wire (chatGPT actually recommended it):

Tinned Copper Battery Power and Ground Wire 1/0 4 and 8 Gauge Cable

Buy Tinned Oxygen Free Copper Automotive and Solar Battery Cable. KnuKonceptz Ultra Flex Wire and Ground Wire is Available in Black, Blue, Red, and Neon Colors

www.knukonceptz.com

The stats on this stuff are unreal compared to the others I'm looking at. Rated at 700A, 36g strands (10.9K total), PVC jacket, and it's relatively cheap?!

This seems too good to be true, are there any known downsides to this many strands? There isn't a lot of info on the net about this stuff and a search on this forum found only 2 posts that even mention Kolossus wire. I would think it would be mentioned more due to its unusual stats.

Anyone have any info on this stuff? Is there any reason I shouldn't use this as my ground?

PS I'm using temco bare copper wire for the rest of the setup.

 

[BentleyJ]

This type of fine stranded wire is more difficult to strip without cutting some of the conductors and then the bare wire expands more so special compression lugs with a larger ID are needed but are more difficult to find. Sometimes listed as DLO cable connectors and lugs.

 

[svetz]

Will's recommendation for 1/0 has an ampacity of 440 Amps. Oxygen free copper (OFC) is suppose to have less resistance, so should generate less heat. Maximum amps is that at which the cable can radiate heat safely (e.g., temperature doesn't continue to climb). Pulling 700 A for a few seconds isn't the same as continuous. Given all the talk on "speaker" wire on that page, can't help but think that's not what you want.

So, knowing nothing about it really...

If the two wires are the same (e.g., strands, tinning, insulation) then given V=iR, for the same voltage i1R1 = i2R2 or 700 / 440 = ROFC / R = ~1.6.

A quick look up and the resistivity of Oxygen free cable to be 10.3 Ohms-circ mil/ft @ 68°F. Aluminum = 16.782 ohm-circ. mil/ft. So, just comparing oxygen free copper to aluminum the ratio looks 1.6 ... but aluminum isn't anywhere near as good as good copper. The whole "ohm-circ mil/ft" unit spec seems to be a speaker-wire spec. There are a ton of alloys of copper with different resistances, but when I give Co-Pilot the numbers for oxygen free copper and then ask for regular copper wire it comes back with 10.37. 10.3 / 10.37 ≠ 1.6.

So, just looking at that I'd say you're right to be suspicious. Possibly the finer wires do make a difference with the "skin-effect" found in alternating current. But, I'm dubious it translates into a 60% increase for Direct Current. Linked @Will Prowse as he can probably answer it off the top of his head and if it is really good he might decide to update the recommendation. If it is fake, or the amps are mythological, might also make a good cautionary video.

 

[S Davis]

DLO is about the same price, I would just stick with DLO it is very tough wire.

 

[davros]

It is car audio stuff, I would take all claims with a grain of salt. No type or spec approvals that I see.

 

[Robert T]

DLO is about the same price, I would just stick with DLO it is very tough wire.

View attachment 285872View attachment 285873

DLO sounds like it might be perfect for my application, however I'm worried it might not be flexible enough, how does the flexibility compare to other options? I see the strand count is only in the 500 range.

 

[S Davis]

 

[Robert T]

View attachment 285879

I'm uncertain if DLO wire is suitable for my application because it doesn't seem to be designed for repeated movement, as the slideout goes in and out the wire will have to bend and straighten, while this won't be super frequent, it could still be hundreds of times over years.

I'm leaning towards tinned Ancor marine grade 4/0 wire, which has a much higher strand count and is the closest thing I can find to tinned welding cable which is obviously designed for a lot of movement.

Unless there is some evidence DLO wire will also hold up to frequent movement, which I can't find any info on, it doesn't seem to be designed for it though.

Any further advice would be appreciated!

 

[Yurtle]

I'm uncertain if DLO wire is suitable for my application because it doesn't seem to be designed for repeated movement, as the slideout goes in and out the wire will have to bend and straighten, while this won't be super frequent, it could still be hundreds of times over years.

no other way to install such that your wire doesn't need to move in/out with the slider?
if this is a ground, maybe sufficient existing continuity b/t slider & main frame?

 

[Robert T]

no other way to install such that your wire doesn't need to move in/out with the slider?
if this is a ground, maybe sufficient existing continuity b/t slider & main frame?

I felt like I needed to reach the main frame but I think you maybe correct, the way the slider works there seems to be a lot of continuity, excellent suggestion, thank you!

 

[Robert T]

no other way to install such that your wire doesn't need to move in/out with the slider?
if this is a ground, maybe sufficient existing continuity b/t slider & main frame?

Despite the fact that most of the slideout hardware is painted (edit: not the spots I'm using to test continuity, but the moving parts between the frame and the slideout are mostly painted), I'm getting a consistent continuity reading of .1 ohms between the outer edge of my slideout and my main frame. It starts at .5 and drops to .1 in a few seconds so I think I am good to go!

 

[Robert T]

BTW I ended up going with Battery Cables USA 4/0 Marine Grade Tinned Copper Battery Cable for my ground wire. I wanted a tinned cable since the ground end will be exposed on the underside of the RV, although I do plan to cover it with some kind of protectant, I figured tinned was a good idea.