I recently did a lot of wiring in my old house and was always thinking about why there are separate neutral and ground wires when they both connect to the same terminal in main panel. Why can't it be only one wire serving both as ground and neutral? more precisel, why neutral contact of all 110 V fixtures couldn't connect just to the ground wire?

 

The grounding wire is just for fault current. It is typically a bare wire and is not meant to carry any current for more than a split-second before the fuse or breaker trips. The grounded conductor, (white wire), is insulated and is a current carrying conductor. If you connected a fixture's white wire to a bare ground, you would have electrified your bare ground all the way back to the panel. This bare ground is often connected to the plumbing. Now all of your water pipes and plumbing fixtures are "hot" too. See how this could pose a problem?

Hope this helps a little bit, somebody will probably be along to expand on this.

 

Great way to demonstrate electrocution.

 

It should be THOUGHT of the piping being connected to the grounding system instead of the wiring system connected to the piping. Really in theory the pipe should only be connected at one point to the grounding system.

 

Good point!