Eli5 – Why is there both neutral & ground wires in light switch?
In: 5
Ground is not meant to be used. What I mean is that during normal operation, no current flows through the ground wire. Ground is there in case of a fault. If something happens and the current can’t make it back on the common wire, there is a second path available… Well, there’s always a second path available, it could be through you, though, and we want to avoid that. So we make the ground wire which has much less resistance than you do so electrons are incentivized to flow there instead.
In a switch, there are not a ton of things that can go wrong, but imagine if it was installed poorly and the hit wire came loose and touched the box. The outlet is screwed into the box, so there might be 120V on those screws if you touch them. I’ve also seen some with metal plate covers instead of plastic. The whole thing would be hot, then. But with a ground wire, as soon as the hot touches anything other than where it’s supposed to be, that should be grounded which will instantly trip the breaker due to a ground fault.
Btw, while we were building the house I lived in during middle and high school, they didn’t hook up the ground immediately because things were still in flux. I got a pretty good poke flipping on one of the outlets because it was floating. Probably at 120V, though it could have been less of it was just stray inductance. I lived, but that’s not always guaranteed. Best to be safe.
Latest Answers