How many connections are necessary for an isolated line to reach zero if it is capacitive coupled to an energized line?

An isolated line that is capacitive coupled to an energized line requires two connections to reach zero potential. This is because capacitive coupling allows the isolated line to pick up voltage from the energized line through the capacitive effect.

In order to bring the isolated line to a zero potential, it needs to be effectively grounded or connected to a point of reference. The first connection serves to ground the isolated line, allowing the induced voltage to dissipate. The second connection can either be another grounding point or a connection to a neutral point that ensures the isolated line is completely removed from any induced voltages.

One connection is insufficient because it does not ensure that the induced voltage will safely dissipate to ground. Without a second connection, the isolated line could still remain at a potential due to the capacitive coupling. Similarly, three or four connections would exceed the necessary requirement to reach zero potential, making the configuration unnecessarily complex. Thus, two connections are the optimal number needed to securely bring the isolated line to zero potential.