Want to bet how many homes out there meet the required codes? Would you have tried it with your wife IN the pool? Don't answer that! I might question your intentions.
As a matter of fact, I was in my electrical apprenticeship when a near naked man greeted our class in an electrical lab that we used for hands on learning. We were told to sit down and stay in our seats. The man (wearing only shorts) proceeded to wrap bare wire around his upper body and got into a large tub filled with water and told the instructor to "Plug me in!)...
Let me back up here. The person in shorts was going around the country with his tub and introducing the GFCI (note the difference in the acronym from the now accepted GFI) a new device that...well, let's get back to the story...
So, the instructor first points to the LED on the receptacle and tell us to note the LED is on and the receptacle is energized. Then he plugs in the plug on the bare wire and...nada. We do hear a click and the light on the receptacle goes off, but the guy in the tub is unharmed! Then, he climbs out of the tub and takes the wire off his body. He spent the rest of the session explaining how the GFCI works.
I'm not gonna try to explain how it works, but I will tell you what you'd see if an oscilloscope was used: First, imagine an ordinary single phase 120VAC sine wave. The straight line is 0 volts, the line that shows the voltage is rising and falling between (doing this on memory alone, correct me if I'm wrong) 167VAC measured from the top of the positive sine to the bottom of the negative sine. (I was wrong when I first posted and VOS caught it, bless his heart) Got that? Now imagine that the voltage induced just starts to ascend and is shut off very close to the straight line that signifies 0 volts. That's what happens when a GFI trips. Practically no voltage before shutting down and that's the life saver. I don't know or remember exactly what voltage it trips at, but it's so quick nothing bad can possibly happen.
It's been ~ 40 years since that demonstration and I've never seen a GFI fail. So, yeah, I know what would happen if I threw my wife in the pool with the extension cord plugged into a GFI wrapped around her...nothing. Would I try it? No.
With no GFI, the person would die. He/she would be electrocuted. Another thing to remember, there is no second chance with electrocution. You die. I know state mandated electrocutions have failed, but that's because the electrocution process failed. If you actually get electrocuted there are no second choices.
One more thing about the GFIs: They should be used when a double-insulated tool is used. During the course of their evolution, someone discovered that not only do they interrupt the circuit if it is suddenly grounded, but they also measure leakage from hot to neutral wiring and trip immediately if something is amiss. We had a guy get a wicked shock when using a double-insulated drill and immediately rewrote our hot work procedures to include using a GFI when using double-insulated tools. This information is included in the paperwork you get when you buy most GFIs. Or was.
Edited by Rich, 02 April 2013 - 11:42 AM.
Mistake in voltages