Re: Bootleg grounds
One of the key differences between mechanical stuff and electrical stuff is that the electrical needs a complete path. You can fill a bucket with water, throw it on the floor, and leave it there, without ever having to put it back into the faucet. Not so with wires. Power that flows from the panel to a receptacle, and from there into the lamp that you plug into the receptacle, has to find its way back to the panel. If it has no path, then there will be no flow, and the light will not go bright.
But there is a twist to this concept. Electricity will take every available path back to its source. If some paths are of higher resistance than others, then most of the current will follow the lower resistance path. But some current will take the high resistance path, for no better reason than that the path exists. It?s like driving from one place to another. Most people would prefer to take the highway. But if there are alternate routes, and if all alternate routes are longer and slower than the highway, you would not expect there to be any drivers that would choose to take them. But current will take every available path.
The normal path goes from the panel, via the ?hot? wire (i.e., the black wire), to the receptacle, through the plug, up the lamp cord and into the bulb, back through the lamp cord to the plug and the receptacle, and back to the panel via the ?cold? wire (i.e., the white wire). Now suppose the lamp has a broken something or other inside, so that the hot wire touches the frame. Suppose further that you are touching the frame as well. The normal path of current still exists, and most of the current will continue to flow along that path. But now there is another path. Current can make its way back to the panel by traveling into your hand, through your body to your feet, into the floor, through the dirt under the house to the ground rod outside the panel, and back to the panel via the ?grounding electrode conductor.? You won?t enjoy that experience.
The purpose of the third prong is to give yet another path for current to flow, but only if there is a broken something or other like I describe above. The green wire (i.e., the one connected to the round part of the 3-prong plug) is connected to the frame. When the failure occurs, there are now three paths of current. Two I have already described. The third goes from the frame to the ground wire, into the third prong of the plug, and along a ground wire directly back to the panel. This is a low resistance path, so it will draw more current than your body will draw. It will, in fact, draw enough current to trip the protective circuit breaker, and thus terminate the event before you can be harmed. Please note that throughout the house, every frame of every piece of equipment, and anything that has a 3-prong plug, are all connected to each other via this system of ground wires.
All the above was background information. Now to directly answer your question. If you connect the neutral to the ground inside a single outlet, then you have connected that neutral to everything in the house that has a ground wire. That provides a fourth path of current, different than the three I?ve mentioned before. This path goes from the light bulb, back through the lamp cord to the plug and the receptacle, but now some current is diverted to the ground wire, and will make its way back to the panel via the each and every piece of equipment in the house. Even if you never have a piece of equipment break, you will always have this extra path. And if you touch a lamp, you could get a shock, even if that lamp were in a different room than the offending receptacle.
