Compact conductors

[MasterTheNEC]

I have installed 15kV copper with compact strands. The customer supplied the cable, 3 conductor jacketed MC listed for direct burial. I think that is the only time I have seen compact stranded copper.

Oh it's possible...just not practical from a manufacturers standpoint to compact CU.

 

[don_resqcapt19]

Oh it's possible...just not practical from a manufacturers standpoint to compact CU.

It was not a custom cable, so it must be practical for the manufacturer who made it

 

[rrc14]

The biggest differences are probably the provision for a smaller diameter and a less rough surface that deforms less easily (compared to normal stranded). Both are closer to the behavior of solid wire. I would guess that a connector rated for solid of the same wire size would do quite well with compact stranded. But:
The most important factor in the listing is probably just that all of the tests were run specifically with compact stranded instead of just normal stranded and/or solid.

So, is normal stranded conductors considered compressed or concentric?

 

[kwired]

So, is normal stranded conductors considered compressed or concentric?

I believe the image in post 2 answers that question.

solid, compact and compressed conductors have a smaller diameter then a regular stranded conductor of the same standard size or AWG because they have more material in a smaller cross section - it is the material that carries the current not the cross sectional area.

 

[p real]

Word for the day: interstice. The spaces between adjacent components of a multiconductor cable. As an engineer explained to me once, apparently that is a factor that is considered from an engineering standpoint when wires are twisted together to form a stranded wire conductor. Always amazes me just how many things to be considered to make an electron behave.

 

[GoldDigger]

... Always amazes me just how many things to be considered to make an electron behave.

A great quote from a speech by former Chicago mayor Richard Daley: "I foresee a great future ahead of us once the technologists have learned how to harass the atom."

 

[MasterTheNEC]

It was not a custom cable, so it must be practical for the manufacturer who made it

Well lets just say it did not come from a manufacturer I know......Indeed it may be a manufacturer who is accustom to doing compact CU but it is not "practical" for building wire. The largest manufacturer of THHN/THWN-2 i CU doesn't make a single piece of compact CU....but in AL it's all they make.

 

[MasterTheNEC]

So, is normal stranded conductors considered compressed or concentric?

No,

The normal is usually "concentric" strand which has a center core and you have layers of conductors wrapped helically around the central core. Then you have "Compressed" which is a concentric strand that passes a die and reduces the diameter by roughly 3%. Then you have "Compact" which is also a concentric strand conductor now is also further devoid of any indices via a die as well to look very similar to solid conductors, yet maintains the ampacity value of the original concentric stranded conductor. The "compact" conductors reduce the diameter of concentric strand by approximately 10%.

With that said...many individuals overlook the fact their is a Table 5A which covers the areas of compact conductors.

 

[don_resqcapt19]

Well lets just say it did not come from a manufacturer I know......Indeed it may be a manufacturer who is accustom to doing compact CU but it is not "practical" for building wire. The largest manufacturer of THHN/THWN-2 i CU doesn't make a single piece of compact CU....but in AL it's all they make.

I think it is fairly common in medium voltage multi-conductor cables. I have never seen it as a single conductor. Any yes, it is a very stiff cable to work with.