I completed my apprenticeship program in NYS working mostly in commercial and industrial applications. We pulled stranded THHN for all of our branch circuits ran in conduit. The only time we would use solid THHN was in control panels. I recently moved out to Montana and it seems like everyone uses solid wire. I'm referring to 20A and 15A circuits pulled through conduit. Several months ago someone saw me pulling stranded wire and told me it was a code violation to used stranded wire in a commercial building...i've had several people tell me the same thing since. Am i missing something?? I've never seen solid wire used, and since moving out here thats all i see, and i have people telling me with absolute certainty that i'm wrong. I've never come across anything in the code book saying you cant but then again i havnt looked specifically for it because I've never questioned it up until now.
Ok, here it is.
Stranded requires less pulling tension. Stranded tends to jump off the reel and kink up requiring a helper. Stranded is difficult to wrap around the screws of devices to make a reliable connection. Backstabbing, mmm no, I don't think so. :jawdrop:
So stranded gets one thumbs up :thumbsup: and two down :thumbsdown::thumbsdown:.
Solid can be more difficult to pull. Solid pulls smoothly off the reels unattended. Solid terminates easily on the screws of devices. God forbid but you can backstab with it.
So solid gets one thumbs down :thumbsdown: and two thumbs up :thumbsup::thumbsup:.
So to me solid, for the work I do, is the clear winner.
But it's all a matter of preference, and anybody that tells you that using one or the other is a code violation doesn't know what they are talking about.
Edit to add:
nick h said:
The only time we would use solid THHN was in control panels.
Actually my experience is just the opposite and I myself prefer using stranded in panels.
-Hal