What purpose does spacing serve between cables in a manhole?

Spacing between cables in a manhole is primarily important for allowing cable movement. This aspect of installation is crucial because it accommodates thermal expansion and contraction of the cables. As cables carry current, they generate heat which causes them to expand; if they are too tightly packed, the expansion can lead to physical wear, insulation damage, or even failure of the cables. By allowing some space, the cables can move slightly without causing harm to themselves or adjacent cables, thus promoting longevity and reliability of the electrical system.

Additionally, spacing can contribute to maintenance efficiency, as it allows access to individual cables for inspection or replacement without having to disturb others. Properly spaced cables are also better positioned to receive adequate air circulation, which can assist in cooling, though that is not the primary purpose of the spacing itself.