What device is installed to protect cables from damage by drywall screws or nails?

The appropriate device to protect cables from damage caused by drywall screws or nails is a steel plate. Steel plates are used as a physical barrier between the cables and the surface of walls where drywall is applied. They are particularly effective in preventing incidental contact from screws or nails that may be driven into the wall during installation or renovations, safeguarding the integrity of electrical and low-voltage wiring.

Plastic conduit, while helpful in protecting cables from environmental factors and physical damage, is typically used in applications where wiring needs to be run outside of walls or in exposed areas, rather than specifically against the potential for puncture by screws and nails. Wire wrap is generally used for bundling wires and preventing strain but does not provide a solid protective barrier. Cable trays are designed for organizing and supporting runs of cables but do not offer direct protection from penetrating fasteners in walls.

Thus, the use of a steel plate is a targeted solution for shielding cables from potential damage caused by tools and hardware during typical construction or remodeling activities.