There are totally different causes for all sorts of wire and cable together with naked copper. Generally wire has insulation and typically it would not for particular causes. Engineers work onerous to offer a kind of wire for each utility on the market with approvals to go together with it.
Naked copper is also referred to as a floor wire. It isn’t insulated in any respect so it has no safety. It’s principally utilized in properties as a floor wire and has the very best conductivity with out insulation. So so long as it is not going outside then electrical contractors do not thoughts utilizing it.
Naked copper can also be the bottom for many kinds of wire and cable. It comes strong or in smaller awg sizes wrapped collectively to equal the identical gauge. Utilizing the smaller awg sizes offers the wire extra flexibility to bend round corners. You would possibly assume that you’d all the time want probably the most versatile as a result of it may solely be higher however that is not all the time the case. Generally electrical contractors want it to be extra stiff to allow them to ship it a good distance by conduit.
A inexperienced THHN wire is also referred to as a floor wire when the wire must be outside. Inexperienced calls out the very fact the THHN is a floor wire and the rationale for the insulation is so it has safety towards moisture. It might then go outside and in conduit whereas it nonetheless acts as a floor wire. The explanation for utilizing it indoors with out insulation is just because it is cheaper. Generally you would possibly see this wire with a yellow stripe as effectively.
There is not all the time a floor wire in each cable. In case you want one then I like to recommend speaking to your cable gross sales particular person and ensuring they know that as effectively. Most firms that offer wire additionally provide the naked copper so that you should not have an issue getting it if you happen to want it. You’ll be able to often request a specification sheet to be sure you are getting the precise cable you might be on the lookout for.