Solid Conductor
A solid conductor is a cable type in which the entire cross-section consists of one massive copper strand. In fixed installations it is a cheap, easily terminated solution that holds its shape; but because it fatigues and breaks under repeated bending and vibration, it is not used in mobile installations.
When a solid strand is bent, a permanent elongation forms on its outer surface. If the same point is bent repeatedly, the metal work-hardens and cracks; because the break usually stays inside the insulation, it is invisible and the fault presents itself as intermittent contact.
- Advantage: the end does not fray, it goes straight into a terminal block, no ferrule is needed.
- Disadvantage: on a vibrating vehicle and in constantly moving connections its life is short.
- Termination: in a screw terminal a solid strand can plastically deform and loosen over time; retightening is needed after the first run.
In building installations and for jumpering inside fixed panels, solid conductor is still widespread. By contrast, do not use solid cable on any route on a tractor, crane, caravan or construction machine. A significant part of the "appears months later, disappears when the road is smooth" faults we see in the field comes from solid conductors run onto a vehicle breaking inside their body.
Context in which this term is used: Installation, redundancy and field continuity