Which condition can lead to generator brush arcing?

Generator brush arcing is commonly associated with low spring tension. This condition occurs when the brushes, which are components that conduct electricity between stationary and rotating parts of the generator, fail to maintain adequate contact pressure against the rotating commutator. When spring tension is too low, the contact between the brushes and the commutator becomes inconsistent, leading to poor electrical connections. This inconsistency can create high resistance at the contact point, leading to localized heating and arcing. Over time, this arcing can cause wear on both the brushes and the commutator surface, potentially leading to further electrical and mechanical issues within the generator.

In contrast, while overheating components, high spring tension, or incorrect brush material can also cause various issues within a generator, they do not typically lead to the same arcing conditions directly attributed to low spring tension. High spring tension may ensure better contact but could lead to excessive wear or damage if it's too high. Incorrect brush material can lead to poor conductivity or rapid wear but does not inherently cause arcing in the same direct manner that inadequate pressure does.