wa8yxm wrote:
Question: (Answer to follow) Why is the safety ground wire there in the first place.. I mean the house I grew up in was wired in the early 1950's and did not have safety grounds?
Answer: Well, the key is in the name, SAFETY ground.. At one time (And still today in some places) in order to save wire,,, (Needed at one time by the military) they used the EARTH as the neutral, if you had 120 volt service there was only a single wire from pole to house, (Well it was 110 back then) if you had 220 volt, there were two wires, the NEUTRAL was the earth itself.
Since there still is an earth ground at the pole in many places.. What happens if you are holding a tool, say a Skill hand grinder (like a Dremel) and it has a hot to case short (Well when that happened to me, being a bit odd, the tool went flying without permission.. thus protecting me... Kind of hard on grinding points though..> A genuine dremel quickly replaced it)
NOTE: I am not making that up.. It really happened.
The reason is that though for most things you can think of electricity a lot like water.. Where as Water takes the path of LEAST resistance, electricity takes all possible paths And when that puppy shorted out I became a "Return path" via ground.
The safety ground thus takes the hit and trips the breaker, Protecting me (Had it had a 3 wire cord).
So why is it not needed with a small generator or inverter?
Well. if the generator or inverter is NOT GROUNDED, then should you grab the hot wire in your bare hand.. Were is the current path? It is still an open circuit, you are safe.
That said. I do not recommend it. Usually you will get quite a tingle due to capacitive coupling which is a whole nuther bucket of .. Stuff. I do not wish to go into.
(I have gotten that nibble many times however, IT's annoying, not dangerous)
You have some good points there. However, even with an isolated power supply (which a portable inverter or generator would be) a ground wire can and will still do its job if you are using a metal cased device. Also, a GFCI outlet (which many mid-size inverters now have) can be used to enhance your protection.
BTW, as an aside, did you know that if you are in a house that has an older 2-wire electrical system (And not a 3-wire grounded system), you can put GFCI outlets in as a substitute? I read somewhere that if you have a house with older wiring and it is not practical to replace/upgrade that wiring, use of GFCI outlets is permitted instead.
Cheers!
Mike
