Interesting thoughts about removing grounds

Keith Hilton · Post by **Keith Hilton** » 31 May 2002 10:34 am

Here is something to think about the next time you think about cutting a ground off an electric cord. The 120 volt AC receptical plug is really much more than 120 volts AC. You see the 120 volts is the RMS, not peak to peak. To get the peak to peak value, you double 120 giving you 240, then multiply by 1.414. This means you are really dealing with 339.36 volts AC. No wonder it hurts so much when you get hit with it! According to the National Electrical Code any voltage over 30 volts is dangerous. According to the National Electrical Code any current over .005 amps is dangerous. Most 120VAC circuits are on a 20 amp breaker. 20 amps is 4,000 times more current than is needed to hurt you. Just a reminder to be aware of what you are working with.<FONT SIZE=1 COLOR="#8e236b"><p align=CENTER>[This message was edited by Keith Hilton on 31 May 2002 at 11:36 AM.]</p></FONT>

Greg Cutshaw · Post by **Greg Cutshaw** » 31 May 2002 11:36 am

Keith,

Although the peak to peak voltage is 1.414*2*120 the peak voltage is actually the highest voltage you are exposed to. The voltage between the wires never exceeds the peak value of 1.414*120. It goes to that peak and then reverses and reaches the same peak in the other direction. The maximum potential you are exposed from one side of the line to the other is about 170 volts. As you said not a lot of fun and certainly lethal in any case.

Greg

Keith Hilton · Post by **Keith Hilton** » 31 May 2002 6:49 pm

Greg, we both are correct, depending on which way you think about it. It is 170VAC line to line. On a scope, positive peak to negavtive peak,it is 339.36VAC. Here is an interesting story on this subject; Deer kept eating my neighbor's garden. He ran a wire around the garden, and hooked a 100 watt light bulb to the wire as a fuse, and plugged it all into 120VAC. He thought the 100 watt light bulb, would act as a fuse and would burn out before it killed a hungry deer. Next morning there was a dead deer by the garden. A sad but true story!100watts=120V times current. This means the deer got .8333amps of current. Less than one amp! One amp would be 200 times the safe limit of .005 amps. It is simply amazing how little current can kill you. And to think, this poor deer wasn't even guilty of removing the ground plug from his amplifier cord!