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# voltages

## voltages

#1
06-27-04, 06:17 PM
sahati
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voltages

Can someone help me with an electrical question?

#2
06-27-04, 06:56 PM
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Uh........why yes...yes we can!!!

#3
06-27-04, 07:15 PM
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But only if you ask it.

#4
06-27-04, 07:40 PM
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Roflmao!!!!!!!!!

#5
06-28-04, 09:49 AM
sandsmarc
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Alright, since he won't ask a question on voltages, I will. How come when discussing a 240 volt line, it is sometimes referred to as 220 volts, other times 240 volts, and still other times 250 volts. Shouldn't it always be a single value?

#6
06-28-04, 11:22 AM
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These numbers are all within the normal tolerances. Appliance manufacturers have to design so that their equipment will work on any of the voltages. Sometimes it's a difference betwee one utility company and another. Sometimes it's a difference between one time of day and another. And sometimes it's a difference between customers close to the substation and customers far from the substation. It applies not only to the higher voltages (220, 230, 240) of course, but to the lower voltages (110, 115, 120). We normally use all these numbers interchangeably. 120 and 240 are the nominal values used in the code.

#7
06-28-04, 04:34 PM
sandsmarc
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Great, thanks for clearing it up. I've always wondered about that.

#8
06-30-04, 01:30 AM
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Where "one ten" came from

What I had wondered about is why so many people say "one ten" or "two twenty". Do they have a specific reason to be stating the lower end of the tolerance range? I've done some research on this and learned that when Thomas Edison first installed his DC lighting system in New York City, it was a 110/220 volt system with a grounded neutral center conductor much like we have today. Edison is incorrectly credited with inventing the light bulb and installing the first electrical service. Light bulbs had been around for about 30 years before that time, and at least one other company was already supplying electricity in New York City and some readings suggest (the connection wasn't too clear, so this is not for certain) it was operating at 500 volts DC. So while we can't give Edison credit for inventing the light bulb (instead, he made it more practical), it appears we can give him credit for setting the value so many people still, to this day, think is the voltage of the electrical power in the outlets and light sockets.

I'm still trying to figure out when it officially became 120 volts and 240 volts. And that might be hard to determine since back in those days (late 1800's to very early 1900's) there were many small startup electric companies just picking and choosing their own voltages, system configuration, and AC frequency (or DC). Some company may have chosen 120/240 a long time ago, and prevailed. It wasn't Edison, but I might guess for now that it was George Westinghouse (or one of his engineers, or maybe even Nikola Tesla himself).

#9
07-04-04, 06:26 PM
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I hope our sarcasim {spelling ???} didn't upset the O.P.!!!! LOL

#10
07-04-04, 06:45 PM
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