I've been doing some research and am starting to understand the difference between bonding and grounding a little more and the foolishness of attempting to "ground" an outlet to a metal water pipe / grounding rod. My hope is to hire an electrician shortly to upgrade my panel. When talking to him, how do I make sure he knows that'd I'd like the panel both bonded (my understanding is that this allows the electrical current to go back to its source, i.e. the power plant instead of through a person in the event of a ground fault) and grounded (which, based on my understanding, only serves as current "drain" in the event of a high voltage fault, like lighting, for example)? Is it common practice for an electrcian to bond and ground the panel when it's being updated?

Also, a separate question I have. Is it safer in general to use plastic boxes as opposed to metal, since if a wire comes loose, the plastic will theoretically be less conductive than the metal? I realize that a bonding path should protect against an energized metal box, but what if there is a fault in that path? I just don't understand why it would ever make sense to use metal. What am I missing?

Thanks!

You know about these bits? Piranhabits Flexible Fish Bits available from Lashen Electronics They are like 54" long.

Q2: Plastic won't support a ceiling fan. Metal boxes might pop a breaker if a wire came loose and you would know immediately.

Q1: It's a bit harder. Ground and neutral get connected together in one place. This provides a reference point. i.e. What is zero volts. Your cable TV is tied to this reference too.
The ground rod or copper water pipe can provide lightning protection. You don't want lightning to raise the reference of other circuits. Your plumbing system and your gas supply may have to be bonded as well. The neutral to ground bond also provides fault protection for things like insulation breakdown in a grounded appliance. The fault current goes to ground and doesn't raise the ground potential like a stray water pipe can.

There are lots of details missing from the above post, but it should give you a general idea.

I didn't know about those bits; they could potentially be very helpful.

So, current always will flow towards a zero reference point? I realize that electricity and circuits for that matter are a lot more complicated than attach white to white, black to black etc, but is there a simple way to explain where excess current might go in the event of a fault? Does it flow along the neutral (or ground in the event of a fault in the neutral) back to the box where it is then safely dissipated out through the neutral supplied by the utility company?

And by reference, does that refer to volatage reference?

Thanks for your help.