The Robot Devil wrote:Mary Lilac wrote: The alligator clip on the end is meant to clip on to some type of grounded metal (such as galvanized steel conduit), and you can remove it to stick the plug into the
ground plug hole on your wall outlet. Disregard the Voltage markings on the drawing (they are not quite accurate anyway).
This is very dangerous, you should never plug anything into a wall that isn't intended to plugged into the wall. Stray and unbalanced currents and voltages use the grounding to balance load and can be energized. All that is needed is equalizing your potential to the part by touching the part ground or by touching something that has been properly grounded, like an appliance with bare metal that is accessible. Grounding is important but shouldn't be treated as if there is no potential on the conductor, if the grounding conductor is energize it can hurt you or your stuff. I have personally tested grounding conductors with 60-70 volts on them in peoples homes. NEVER plug things into a wall outlets that weren't designed to be plugged in or UL tested.
If your house was built to code, you should be 100% safe in doing this... that is the point of that plug. That plug is connected directly to the ground (i.e. the galvanized steel conduit which is required to be true-earth ground). If this were not 100% safe, it would be a horrible idea to even touch the outside of your computer case... or any case that is metal, in any electronic component that has that third plug.
Seriously, if you have ever been in a house that had 60-70 volts on that grounding hole I hope you called the City, because it would not be long before that house will burn down. This is not up to code, and you run SERIOUS risk plugging anything into any outlet in a situation like that.
Point in fact, when you use the alligator clip to chassis method, you are supposed to plug your case into the wall (while leaving the switch off). This is effectively grounding the entire chassis and your wrist strap to that third plug in your electrical outlet.
The only time I would be concerned is if your house is much older construction (world war 2 era) and you had some 220 V outlets in your house. US electical codes were a little bit more forgiving then, and it is possible that the ground plug was used a neutral while the other two plugs were out of phase 110V lines.
Of course, if that is the case start suing everyone and anyone that was involved with your house sale.