What size wire is this?

Superduper · May 21, 2012

Can anyone tell the size of the main wire? The size is printed on the black sleeve which is in the conduit and not visible. I placed a length of 8-gauge to compare to. Someone here very familiar might recognize it?

I'm trying to determine if I have enough capacity in this box to power a miller dialarc 250 w/o PFC.

dstig1 · May 21, 2012

Seriously?

Nobody can tell you what it is from that picture, with any sort of certainty. And I wouldn't trust anyone's response who would answer it! What is the main breaker on the panel or feeding the subpanel (whichever this is)?

Superduper · May 22, 2012

It's a legitimate question. An electrician would be able to tell from experience by the difference in size from the 8-ga pictured next to it... I think.

It is a subpanel and the main breaker is 100 amp. I think the supply cable is 4-gauge.

Cat_Driver · May 22, 2012

It's simple - The Black stuff is, 10 AWG Solid Copper 600V THHN / THWN E23919

Groo · May 22, 2012

Measure it
American wire gauge - Wikipedia, the free encyclopedia

I think #4 is a bit slim to be supplying a 100 amp panel. I though #2 was the standard for that.

grsthegreat · May 22, 2012

it could be either a #2 or a #4, but its too hard to tell in that picture.

Superduper · May 23, 2012

Well, I measured it but the results is inconclusive. I think it's 2-guage. Measures thinner than 2 but thicker than 4. But on the other hand, I measured the 8-guage (that one I know for sure because it's marked) and it measures a bit thinner than the chart too. So either the caliper I'm using is not calibrated perfectly or the wires are manufactured thinner than they used to.

All the charts I see mentions that stranded diameter varies.