Re: uninsulated overhead grounded conductor
Ed, your points are well taken but there were personal references made to me in previous posts on this thread that had nothing to do with the subject at hand.
Now, you chart is correct of, of course. Review my posts and you'll read I wrote the nominal voltage for most services was 240 and I capitalized every letter of nominal. For the purposes of many motor manufacturer 230 is nominal. That is why many motors are tagged 230 volts. I sent you links to a catalog for single phase motors used on condensor fans. In fact I've sent, and can send again, thousands of references to 220 volt service. Look, if I wanted to nit pick I could go to any text of electrical practical theory and find things that are not literally correct. For example, it is not literally correct that electric current is only the flow of electrons. If it were, a car battery wouldn't work, to say nothing of transistors. Nevertheless, I teach it and say it because it simplifies a more important discussion.
Look, if this thing with 220 volt service still makes anyone suspect, I'll send you to a site referenced by the electrical inspectors for this nation that makes reference to 220 volt services.
All this is not to say you don't have a 240 volt service in your neck of the woods or that it is not a common service voltage or that 240 is not a nominal voltage. 208 volts single phase is still fairly common and 220 volts was at one time very common.
Voltages are pushed to their highest limit to keep conductor size to a minimum. When copper prices went through the roof the manufacturers and utilities saw their bottom line in trouble. To them, 240 volts is lot more appealing than 208. Remember they sell KVAH and it takes less copper to deliver KVAH at a higher voltage.
By the way, if I really wanted to get heavy on safety, I'd get into aluminum, and if you want a gut opinion from me-I'd outlaw for electrical use.
This c--- started in wide use in the sixties.
Bob