What does the markings U and R stand for in Type SE Style U and Type SE Style R. in 310.14

I have no doubt 'R' stands for round.

I had always believed the 'U' meant flat as all SEU I have seen is flat.

However I have been shown that the 'U' stands for un-armored.

At one point typical SE cable was armored.

Ok, Thank you. I looked in the American Electricians Handbook,I couldn't find it I was sure it would be in there and it probably is but I didn't find it.

Both Southwire and Encore Wire agree with Iwire. That's a lot of wires. Has anyone ever actually seen armored service cable?

-John

[This message has been edited by BigJohn (edited 01-27-2007).]

so does AIW and Cerro Wire


from Cerro Wire


[This message has been edited by Lostazhell (edited 01-28-2007).]

Thanks Lastazhell, After reading what it says under " U ", I am leaning towards " U " having to do with the way wire is layer in the cable.

...Has anyone ever actually seen armored service cable?...

Several years ago I sent in a picture of some ASE.

I don't know what happened to the picture, but it looks like standard SEU with a flat metal tape wrapped underneath the jacket.