Solid copper wire uses one continuous conductor and works well for fixed, structured runs such as fire alarm and signal-control circuits. Stranded copper wire uses multiple smaller conductors, making it more flexible for speaker wiring and other installations that require easier routing around equipment or connections.

Wire gauge describes conductor size: lower gauge numbers indicate thicker copper conductors that can carry more current over longer runs, while higher gauge numbers offer a smaller, more flexible option for lighter-duty circuits. When selecting copper wire, consider the connected equipment, run length, required signal or power, termination space, and whether the installation calls for a specific cable type, such as plenum or riser-rated construction.

Choose plenum-rated copper wire for cable installed in environmental air spaces, such as plenum ceilings or raised floors, where the installation requires an FPLP or CL3P rating. Choose riser-rated copper wire for vertical runs between floors or through other nonplenum areas that call for an FPLR or CL3R rating, and confirm the applicable local codes before installation.

When selecting copper wire, compare conductor count and gauge, solid or stranded construction, shielding, and the cable’s insulation and jacket ratings for the intended installation. Match plenum or riser construction and ratings such as FPLP, FPLR, CL3P, CL3R, FT6, or FT4 to the applicable space and system, such as fire alarm, signal control, or speaker applications.