Induction: The Other Invisible Killer
Those of us who work with electricity know the dangers of this unseen, invisible force. Some of us have seen electricity when something goes wrong, such as uncontrolled voltages due to phase-to-phase and phase-to-ground faults. We have been trained to “treat it hot until it’s grounded.”
Another invisible killer, a partner to high voltages, is induction. Induction is when you have ungrounded, de-energized lines in close proximity to energized hi-voltage lines. The energized lines create a magnetic field which, if it is of a high enough magnitude, will energize the dead lines with a static charge. The de-energized lines will retain this static charge until it is discharged, hopefully with a set of grounds instead of a human conductor.
If the static charge is large enough it will cause serious injury and or death. We’ve all walked across a carpet then touched something metallic and we get a tingle. When we are talking transmission voltages, that tingle can send you to the promised land.
Let’s not take short cuts. “Treat it hot until it’s grounded,” and don’t forget about the other invisible killer—induction.
Art Torres
July 24, 2006