Shocking find this may save a life

I agree with omard mine is staying in. I betting if I looked for just a few minute I could find an article that contradicts this on completely, gotta love the Internet!

 

Excellent thread. Thank you all. I do appreciated it. Karma up for you guys. Karma down for me!!!

 

NO!!!!! I would trust in the pros. I too, read that article. Just one of the things that confused me. Spark, Tangster and those who argued the point against mine are correct. TG for ground probes. My GFIs go in today. I have never done this kind of work before. .....and yes, I know to throw the breaker before starting!!!!

Thanks again guys. I love this forum.

Peace.......John.

 

From that article -- "Voltages can exist without there being any current. For example, birds sitting on a power line may be in direct contact with 10,000 volts, but they are not electrocuted. Why? Because no current is flowing through their bodies."

This is not really accurate, so I'm guessing Robert Michelson is more of a writer than a "Principle Research Engineer". I have only a B.S., but I have common sense, which many PHDs (Not all, of course) lack.

V=I*R Voltage = Current * Resistance

So if there is no current (I=0) or no resistance (R=0), then there is no voltage potential. So "Voltages can exist without there being any current" is a pile of crap.

His example of the bird on the power line isn't accurate either. There is no voltage and no current flowing through the bird on the wire. It's not that the wire is insulated, and it's not that the current is zero. It's because of the very High Resistance between the bird and it's nearest ground, so current won't travel through the bird. The current is flowing through the wire, and it does not effect the bird. However, if that bird were to stretch a leg or wing to the next grounded wire over, his body would become part of the circuit between the two wires (for just a second or two), the high resistance would become very low, the current would be diverted through the bird to the next wire (ground), and he would become a roasted bird. During the roasting ceremony, there would be a measurable voltage, current, and resistance between the two wings of that bird.

 

LOL. I like that. Academia tends to remove that, does it not. Too much of that there book learnin' (didactic training).

 

No man... you are completely wrong. Of course voltage can exist without there being any current. Your outlet in your house is at 120 volts right now, but unless there is something plugged into it, there is no current present.

 

"Let's get ready to RUMBLE..."
Do you even know what voltage is or how to measure it?

Voltage "is the difference of electrical potential between two points of an electrical or electronic circuit, expressed in volts." -from Wiki for you internet searchers.

Voltage needs to be measured across 2 points of a COMPLETED circuit.

The bird sitting on one wire was not part of an electrical circuit, so put a voltmeter between the head and feet and measured voltage is essentially zero.

Your outlet in the wall is not making a complete electrical circuit with nothing plugged into it. There is no current flowing from the hot to the neutral side, since there is a high resistance (non-conductor) in the outlet housing between the black and white wires. It's not a completed circuit, so no voltage can be measured there. While when an appliance (turned on) is plugged into the outlet, the circuit is complete, and voltage (110 or 120V) may be measured across it.. If you were to measure the voltage in the outlet by plugging a voltmeter between the two outlets, the voltmeter would complete the circuit. 15 amps of current would flow directly through the multi-meter, and... well why don't find out what happens doing that.

 

Not to take away from the ground probe discussion but I thought it was important to let everyone know that if you plan on keeping puffer fish, you should be prepared to protect any and all powercords from them as they will chew them up.

 

Hey Bogie, I am about to install the GFI units into my wall. Before I do so, I need to know, do I just copy the wiring connections that I see on the old unit? Is it that easy. Anything I should watch out for (besides throwing the breaker before starting work)?

Thanks dude. John.

 

Home depot sells a "GREENLEE GT-11 Voltage Detector", which should light up and chirp when you put it near the hot (typically black) wire, with the circuit on. This will assure you if the black wire is indeed hot. I'm not sure if some building codes in other states use the white as the hot, but typically here, the black is hot, white is neutral, and green (or bare) is ground. If your outlets only have the white/black, and the house is wired with BX cable, the steel shield typically acts as the ground.
In newer houses, specifically houses wired with Romex cable, there is always the third bare ground wire. The outlet must have the ground wire (or bx shield) actually grounded in order for the GFI to work right. With the circuit breaker off, there should be continuity between the ground and the copper plumbing and the neutral circuit. In all cases, from what I've seen, the neutral and ground are re-connected back at the circuit breaker box anyway. So yeah, pay attention to the line/lead sides of the GFI box, and follow the directions.