Why is stranded wire used in most powerplant electrical systems instead of solid wire?

Why is stranded wire used in most powerplant electrical systems instead of solid wire?

• A. Solid wire is more expensive
• B. Solid wire is likely to break under vibration
• C. Stranded wire is lighter
• D. Solid wire has higher resistance

Answer: (B)

In powerplant environments, conductors face constant vibration and flexing from rotating equipment and thermal cycling. A solid conductor is rigid and concentrates stress at bends, clamps, and termination points, making it more prone to fatigue and eventual breakage under this repeated motion. Stranded wire, composed of many small strands, can flex and distribute that stress among the individual strands, absorbing the vibration without developing cracks in the conductor. Electrically, solid and stranded wires of the same overall cross-section have about the same resistance, and the weight difference is negligible, so those factors aren’t the deciding factors. The practical takeaway is that stranded wire offers greater mechanical durability in vibrating systems, which is why it’s used in most powerplant electrical installations.

In powerplant environments, conductors face constant vibration and flexing from rotating equipment and thermal cycling. A solid conductor is rigid and concentrates stress at bends, clamps, and termination points, making it more prone to fatigue and eventual breakage under this repeated motion. Stranded wire, composed of many small strands, can flex and distribute that stress among the individual strands, absorbing the vibration without developing cracks in the conductor. Electrically, solid and stranded wires of the same overall cross-section have about the same resistance, and the weight difference is negligible, so those factors aren’t the deciding factors. The practical takeaway is that stranded wire offers greater mechanical durability in vibrating systems, which is why it’s used in most powerplant electrical installations.