A copper conductor used in electric lighting or power stations, to
receive the current from all the dynamos. The distributing leads are
connected to the bus wires.

In the three-wire system there are three; in the two-wire system there
are two bus wires.

The name is undoubtedly derived from “omnibus.”

The bus wires may be divided into positive, negative, and, in the
three-wire system, neutral bus wires.