Down to Earth About Grounding

摘要

Ben Franklin already knew enough about grounding to keep the portion of the kite string he was holding dry. Otherwise, when the lightning streaked down the wet part of the line and hit the key, he might have received more than a mild shock when he moved his hand near the key. Legend has it that the experience was striking enough to send him indoors where he set about inventing the lightning rod. Fast-forwarding a few centuries, grounded electrical systems are now the norm throughout most of the world, although some European countries operate ungrounded systems, which are monitored to identify faults if they occur.