If this is the case, Then why can I go outside and take an extension cord, connect the Hot (Black /small blade) side to a light bulb and connect the other side of the light bulb to a Ground Rod (Connected to nothing but earth), and it lights up ?
,Do you understand the difference between parallel and series connected resistance?
I think that you could learn more from some Experimenting.
I do this experiment several times a year. I am having different results than what you are having.
If Earth Ground is that bad then why does the NEC even require it ?
The answer is found in 250.4. There are four reasons to connect a wiring system to earth, 1- lightning, 2- Power surges, 3- unintentional contact with higher-voltage lines, and 4- stabilize the voltage
Using the requirement of 250.56 of the NEC of 25 ohms and 120 volts Ohm’s Law says if I connected a 15 amp breaker directly to an 8 foot rod then only 4.8 amps of current will flow.
Most residential transformers across the US are supplied on the primary by 7200 volts. Using the same 25 ohms this high voltage will push 288 amps of current through the earth. (Unintentional contact) A lightning strike will have a very high voltage and in the event of a strike earth will allow a magnitude of current to flow with that kind of a push. Should lightning strike the high voltage lines the secondary will have a “surge†of 1/30 of whatever the lightning strike was but it will be high enough to push a lot of current through the earth. (power surge)
The power company does everything it possibly can to achieve at the most 10 ohms on their grounding electrodes. Look at the pole holding any transformer and see their conductor going to their electrode.
In most cases across the US the resistance of grounding electrodes on homes will be 300 ohms and upwards. To drive an 8 foot single rod anywhere in America and you will be darn lucky to have less than 100 ohms.
And if you are correct (as You must be) then a GFI for outdoor use is Useless, is it not ?
If you really meant what you said in your last sentence of this post you would have been listening when I explained how a GFCI device works. The connection to earth plays no role in the equation. What makes one open is when there is a difference of .004 to .005 amps between the black and white conductors connected to the device.
A human with a resistance of say 10k ohm and using 25 ohms for earth this would be a total of 10025 ohms. Divide 120 volts by 10025 ohms and there will be about .012 amps flowing. This is just shy of the “let go threshold†but more than enough to trip a GFCI device, almost three times the amount of current to open the GFCI device.
Your light bulb experiment above done with math will be as follows;
120 volts with a 100 watt light bulb and the resistance of the rod at school that averages ~500 ohms. To find the resistance the test was done with a three point reading for a more accurate reading by an engineer three years ago.
To find the resistance of the bulb we will square the voltage and divide by the wattage which gives us 144 ohms
Add the resistance of the rod and bulb and forget the resistance of the conductor being that it is so small will give us a total resistance of 644 ohms.
Now to see how much wattage this circuit will allow to flow we will square the voltage and divide it by the resistance and the total wattage this circuit will allow to flow is just over 22 watts. Yep late at night one might see the bulb glow.