110 vs. 120

[Charlie]

This is not exactly "radio" related, but the discussion on AC/DC sets and house current brings up a question that i've often wondered. Why is our house current usually referred to as 110 volts when it's actually 120 volts? There's 240 (usually referred to as 220) coming into the house, and then breaks off into the 120 circuits at the breakers. My power here is right on the money at 120.0 volts, and I think I have 119.8 at my cabin.

Are other parts of the country actually running 110 instead of 120 in the house? Or is it just that saying "one-ten" slightly faster than saying "one-twenty"? Or, was it actually 110 many years ago and the "name" has stuck around although it's now 120?

I've often corrected people during discussion when they would say 110 or 220... and when I would say "you mean 120 or 240," they would look at me as if i had six heads. Some would even stick to thier guns... until I'd put the probes in an outlet and show them... it's 120!

Also, this brings to mind the electrical items we buy. Most older items show a variety of ratings. They may say 115, 117, or 105-125 volts. Most modern items show ratings of 120, but ocassionally I'll come across something stating 110 or 117. Of course, I can understand that everyone's power likely varied from one neighborhood to another, but if the standard is 120, why not just label the item as 120?

Also, if you buy a pack of GE or Sylvania light bulbs... either standard or soft white, they are rated at 120 volts. If you buy a cheaper brand of bulbs, they are rated at 130 volts... and usually don't look as bright as the GE's. Why would someone make 130 volt bulbs?

I know... many questions here that really don't make a hill of beans... just always been something I've wondered about.