Compact conductors?

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K8MHZ

K8MHZ

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Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
EC friend of mine did a service upgrade and put 3 2/0's in an outside run of 1 1/4" PVC. He said he looked it up in the book, and it was allowed.

Inspector pointed out that the table the EC was referring to was for compact conductors, not everyday conductors. He didn't make the EC change anything, but pointed out the section of the tables the EC should be referring to and just to not do it again. (We have cool inspectors here. They have common sense and everything.)

So, I took a look at a piece of the conductor the EC was using. It sure looked like the strands were pressed out of shape and most of them weren't perfectly round. It was obvious they had been 'compacted', but according to the inspector they were not 'compact conductors.'

If a conductor is 'compact', is that info on the conductor's insulation somewhere? If not, how does one determine if a conductor is compact or not?
 
K8MHZ said:
EC friend of mine did a service upgrade and put 3 2/0's in an outside run of 1 1/4" PVC. He said he looked it up in the book, and it was allowed.

Inspector pointed out that the table the EC was referring to was for compact conductors, not everyday conductors. He didn't make the EC change anything, but pointed out the section of the tables the EC should be referring to and just to not do it again. (We have cool inspectors here. They have common sense and everything.)

So, I took a look at a piece of the conductor the EC was using. It sure looked like the strands were pressed out of shape and most of them weren't perfectly round. It was obvious they had been 'compacted', but according to the inspector they were not 'compact conductors.'

If a conductor is 'compact', is that info on the conductor's insulation somewhere? If not, how does one determine if a conductor is compact or not?
Click to expand...

Well, the inspector is right if they were not compact conductors. The Table C.10 shows 2-3/0 THHN/THWN or XHHW. Table C.10(A) shows 3 for compact conductor. Compact conductor stranding is square instead of round and they nest so you net out with a smaller diameter conductor. It will say compact on the jacket but it should be obvious to the eye.
Sizing is right on the edge here.:)
 
dledinger said:
Table C.10 shows one 3/0 or two 2/0 for THHN, THWN, and XHHW in 1 1/4" PVC.

I agree the inspector was right, all the "A" tables are for compact conductors.
Click to expand...

Oops, typo on my part. I meant to say 2/0 as that was what we were talking about. 2 for 1.25 and 3 if compact.
 
don_resqcapt19 said:
The shape of the stands in a compact conductor vary. The center is hexagonal, the next ring almost triangular, and the remaining rings trapezoidal.
Click to expand...

CompactConductors.jpg
 
K8MHZ said:
EC friend of mine did a service upgrade and put 3 2/0's in an outside run of 1 1/4" PVC. He said he looked it up in the book, and it was allowed.

Inspector pointed out that the table the EC was referring to was for compact conductors, not everyday conductors. He didn't make the EC change anything, but pointed out the section of the tables the EC should be referring to and just to not do it again. (We have cool inspectors here. They have common sense and everything.)

So, I took a look at a piece of the conductor the EC was using. It sure looked like the strands were pressed out of shape and most of them weren't perfectly round. It was obvious they had been 'compacted', but according to the inspector they were not 'compact conductors.'

If a conductor is 'compact', is that info on the conductor's insulation somewhere? If not, how does one determine if a conductor is compact or not?
Click to expand...

UL White Book 2013 ZKST Thermoset-Insulated Wire and ZLGR Thermoplastic-Insulated Wire:
....
Wire and cable employing compact-stranded copper conductors is so identified directly following the conductor size, wherever it appears (surface, tag, carton or reel), by ??compact copper.?? The abbreviations ??CMPCT?? and ??CU?? may be used for compact and copper, respectively.

Tags, reels and cartons for product employing compact-stranded copper conductors have the marking: ??Terminate with connectors identified for use with compact-stranded copper conductors.??
....

AL wires are also in the same sections.
 
fmtjfw said:
UL White Book 2013 ZKST Thermoset-Insulated Wire and ZLGR Thermoplastic-Insulated Wire:
....
Wire and cable employing compact-stranded copper conductors is so identified directly following the conductor size, wherever it appears (surface, tag, carton or reel), by ??compact copper.?? The abbreviations ??CMPCT?? and ??CU?? may be used for compact and copper, respectively.

Tags, reels and cartons for product employing compact-stranded copper conductors have the marking: ??Terminate with connectors identified for use with compact-stranded copper conductors.??
....

AL wires are also in the same sections.
Click to expand...

Thank you!!!
 
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