THHN is the most common building wire: a copper or aluminium conductor with PVC insulation and a thin nylon jacket, rated 90 degrees C in dry locations. Most of it is dual-rated THWN-2, which also allows wet locations at 90 degrees C. The nylon makes it slippery to pull and tough against abrasion, and it comes in a full range of colors for phase, neutral and ground identification.
Pull three 12 THHN, black, red and white, plus a green, the wire cart is already up on two.
Also heard as
- T90 Nylon
Related terms
Pipe
Shop word for conduit of any kind, and as a verb for installing it, as in pipe it.
Home run
Part of a circuit running from the first box back to the panel, or the arrow on a drawing that shows it.
Yellow 77
Wire-pulling lubricant named for a familiar yellow brand, smeared on conductors to cut friction in conduit.