Assumptions about grounding can put you six feet underground. Here are some additional ones to avoid.
- “Grounding makes me safe.” Article 100 of the NEC defines grounding as connecting to the earth, which is a high-resistance path. Its impedance may be 1,000 greater than the resistance of your body. If you apply Kirchoff’s Law of parallel circuits, you’ll see that ground connections won’t shunt enough current to protect you.
- “Electricity follows the least path of resistance, so I just need a low resistance path.” The “least resistance” misconception defies basic electrical theory. If it were true, none of our modern electronics would function. Electricity flows through all paths before it, in inverse proportion to the impedances presented.
- “Grounding makes you safe from shock as long as you have one foot on the ground rod.” Standing with one foot on a ground rod and the other foot elsewhere merely creates another current flow path — through your body.
- “You’ll know a conductor is safe if you ground it.” Do not ground a conductor until you’ve verified there’s no voltage present; reversing this order can create a ground fault.
