The wire in the optical cable

The wire next to an optical cable is often a strength member, grounding wire, or part of a composite cable designed to protect the fiber and provide mechanical or electrical functionality. Common Purposes of the Adjacent WireStrength Members Many fiber-optic cables include aramid fibers (like Kevlar) or steel wires alongside the optical fibers to provide tensile strength and prevent stretching or breakage during installation and operation. These wires do not carry electrical signals but reinforce the cable mechanically.

Grounding or Overhead Protection (OPGW) In high-voltage overhead installations, optical fibers are sometimes integrated into a metallic wire called Optical Fiber Composite Overhead Ground Wire (OPGW). The metallic portion serves as a grounding conductor, protects against lightning strikes, and provides structural support, while the optical fibers inside transmit data. This type of wire is common in power transmission systems above 35 kV.

Ripcords and Jacket Removal Aids Some indoor or distribution fiber cables include a ripcord, a thin strong yarn running parallel to the fibers, which helps installers remove the outer jacket safely without damaging the fibers. While not a functional wire for electricity or grounding, it is often visible next to the optical fibers. Armor or Shielding Wires Outdoor or industrial fiber cables may have steel or aluminum wires wrapped around the fiber core to protect against environmental hazards, rodents, or mechanical stress.

These wires can also provide limited electrical conductivity for grounding purposes.

Identifying the Wire

Indoor cables: Usually aramid fibers or ripcords; they are non-conductive and purely for strength or installation aid. Outdoor or overhead cables: May include steel or aluminum wires for mechanical protection and grounding, especially in OPGW systems. Appearance: Metallic wires are typically silver or gray, while aramid fibers are yellow or white; ripcords are often colored yarn.

Summary

The wire next to an optical cable is not part of the optical transmission itself. Its role is usually to strengthen, protect, or ground the cable, depending on the type of installation. In indoor setups, it is often a non-conductive strength member or ripcord, while in overhead or high-voltage applications, it may be a metallic conductor integrated into the cable for grounding and lightning protection.