# Where did 110 come from? **URL:** \ **Category:** General Inspection Discussion\ **Created:** [October 1, 2014, 2:07am UTC](https://forum.nachi.org/t/where-did-110-come-from/90242 "2014-10-01T02:07:01Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![jjimenez](https://avatars.discourse-cdn.com/v4/letter/j/a87d85/32.png) [@jjimenez](https://forum.nachi.org/u/jjimenez)\ **Post date:** [October 1, 2014, 2:07am UTC](https://forum.nachi.org/t/where-did-110-come-from/90242/1 "2014-10-01T02:07:01Z")
Why do a lot of people say 110/220 when referring to residential wiring? Where did that idea come from? ---
**Author:** ![kramm](https://avatars.discourse-cdn.com/v4/letter/k/96bed5/32.png) [@kramm](https://forum.nachi.org/u/kramm)\ **Post date:** [October 1, 2014, 2:26am UTC](https://forum.nachi.org/t/where-did-110-come-from/90242/2 "2014-10-01T02:26:24Z")
Thomas Edison’s General Electric Company was distributing DC electricity at 110 volts in the United States. Then Nikola Tesla devised a system of three-phase AC electricity at 240 volts. Three-phase meant that three alternating currents slightly out of phase were combined in order to even out the great variations in voltage occurring in AC electricity. He had calculated that 60 cycles per second or 60Hz was the most effective frequency. Tesla later compromised to reduce the voltage to 120 volts for safety reasons. ---
**Author:** ![jjimenez](https://avatars.discourse-cdn.com/v4/letter/j/a87d85/32.png) [@jjimenez](https://forum.nachi.org/u/jjimenez)\ **Post date:** [October 1, 2014, 2:30am UTC](https://forum.nachi.org/t/where-did-110-come-from/90242/3 "2014-10-01T02:30:20Z")
Wow thanks. Makes sense. Did you copy that from somewhere are you just that good? 😉 ---
**Author:** ![kramm](https://avatars.discourse-cdn.com/v4/letter/k/96bed5/32.png) [@kramm](https://forum.nachi.org/u/kramm)\ **Post date:** [October 1, 2014, 2:34am UTC](https://forum.nachi.org/t/where-did-110-come-from/90242/4 "2014-10-01T02:34:43Z")
I remembered the Edison DC part but I knew there was more just didn’t know it so yes I copied it. ---
**Author:** ![cbottger](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/cbottger/32/206_2.png) [@cbottger](https://forum.nachi.org/u/cbottger)\ **Post date:** [October 1, 2014, 3:06am UTC](https://forum.nachi.org/t/where-did-110-come-from/90242/5 "2014-10-01T03:06:08Z")
> [@jjimenez](#): > > Wow thanks. Makes sense. Did you copy that from somewhere are you just that good? 😉 Your just a pup to us old farts it was always 110 & 220;-) ---
**Author:** ![jjimenez](https://avatars.discourse-cdn.com/v4/letter/j/a87d85/32.png) [@jjimenez](https://forum.nachi.org/u/jjimenez)\ **Post date:** [October 1, 2014, 3:23am UTC](https://forum.nachi.org/t/where-did-110-come-from/90242/6 "2014-10-01T03:23:08Z")
> [@cbottger](#): > > Your just a pup to us old farts it was always 110 & 220;-) Get with the times 😉 ---
**Author:** ![sstanczyk](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/sstanczyk/32/175851_2.png) [@sstanczyk](https://forum.nachi.org/u/sstanczyk)\ **Post date:** [October 1, 2014, 3:28am UTC](https://forum.nachi.org/t/where-did-110-come-from/90242/7 "2014-10-01T03:28:58Z")
> [@jjimenez](#): > > Get with the times 😉 Won’t happen Juan. When Charley speaks horsepower, he mean Horse power. Same thing with candlepower. He just counts the candles… :shock: ---
**Author:** ![mclark2](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mclark2/32/170907_2.png) [@mclark2](https://forum.nachi.org/u/mclark2)\ **Post date:** [October 1, 2014, 5:02am UTC](https://forum.nachi.org/t/where-did-110-come-from/90242/8 "2014-10-01T05:02:11Z")
> [@kramm](#): > > Thomas Edison’s General Electric Company was distributing DC electricity at 110 volts in the United States. Then Nikola Tesla devised a system of three-phase AC electricity at 240 volts. Three-phase meant that three alternating currents slightly out of phase were combined in order to even out the great variations in voltage occurring in AC electricity. He had calculated that 60 cycles per second or 60Hz was the most effective frequency. Tesla later compromised to reduce the voltage to 120 volts for safety reasons. Thomas Edison was so against Tesla’s AC Voltage that he made a show of publicly electrocuting elephants to show it was so much more dangerous than dc voltage. It was cheaper to power the country with ac because of the need to increase wire size with dc over long distance. It’s all a very interesting history. ---
**Author:** ![mclark2](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mclark2/32/170907_2.png) [@mclark2](https://forum.nachi.org/u/mclark2)\ **Post date:** [October 1, 2014, 5:03am UTC](https://forum.nachi.org/t/where-did-110-come-from/90242/9 "2014-10-01T05:03:06Z")
> [@sstanczyk](#): > > Won’t happen Juan. When Charley speaks horsepower, he mean Horse power. Same thing with candlepower. He just counts the candles… :shock: Charley told me when he was born the Dead Sea was still alive! :mrgreen: ---
**Author:** ![gromicko](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/gromicko/32/58172_2.png) [@gromicko](https://forum.nachi.org/u/gromicko)\ **Post date:** [October 1, 2014, 6:07am UTC](https://forum.nachi.org/t/where-did-110-come-from/90242/10 "2014-10-01T06:07:09Z")
Thomas Edison was a scumbag with zero business ethics. ---
**Author:** ![hcarvajal](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/hcarvajal/32/209279_2.png) [@hcarvajal](https://forum.nachi.org/u/hcarvajal)\ **Post date:** [October 1, 2014, 11:04am UTC](https://forum.nachi.org/t/where-did-110-come-from/90242/11 "2014-10-01T11:04:16Z")
> [@sstanczyk](#): > > Won’t happen Juan. When Charley speaks horsepower, he mean Horse power. Same thing with candlepower. He just counts the candles… :shock: LOL… ---
**Author:** ![hcarvajal](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/hcarvajal/32/209279_2.png) [@hcarvajal](https://forum.nachi.org/u/hcarvajal)\ **Post date:** [October 1, 2014, 11:05am UTC](https://forum.nachi.org/t/where-did-110-come-from/90242/12 "2014-10-01T11:05:47Z")
> [@mclark2](#): > > Charley told me when he was born the Dead Sea was still alive! :mrgreen: What is this starting to be a “Charlie is so old he…” thread? hahaha. Bert ---
**Author:** ![kramm](https://avatars.discourse-cdn.com/v4/letter/k/96bed5/32.png) [@kramm](https://forum.nachi.org/u/kramm)\ **Post date:** [October 1, 2014, 11:14am UTC](https://forum.nachi.org/t/where-did-110-come-from/90242/13 "2014-10-01T11:14:16Z")
> [@mclark2](#): > > Thomas Edison was so against Tesla’s AC Voltage that he made a show of publicly electrocuting elephants to show it was so much more dangerous than dc voltage. It was cheaper to power the country with ac because of the need to increase wire size with dc over long distance. > > It’s all a very interesting history. That I did not know :shock: Whats really interesting is that when one state sells power to another, some states won’t allow that power to cross their state line in AC form so it has to be converted to DC then cross the state line then converted back to AC. Texas is one such state. If you have ever been in a converter plant, we are talking AC coming in then converted to DC then across a 8’ walkway (the state line) in DC and converted back to AC. :roll: Yes it’s all very interesting. ---
**Author:** ![cbottger](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/cbottger/32/206_2.png) [@cbottger](https://forum.nachi.org/u/cbottger)\ **Post date:** [October 1, 2014, 11:16am UTC](https://forum.nachi.org/t/where-did-110-come-from/90242/14 "2014-10-01T11:16:47Z")
> [@hcarvajal](#): > > What is this starting to be a “Charlie is so old he…” thread? hahaha. > > Bert Bert as long as they are picking on me they are leaving someone else alone;-) ---
**Author:** ![cbottger](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/cbottger/32/206_2.png) [@cbottger](https://forum.nachi.org/u/cbottger)\ **Post date:** [October 1, 2014, 11:22am UTC](https://forum.nachi.org/t/where-did-110-come-from/90242/15 "2014-10-01T11:22:51Z")
> [@jjimenez](#): > > **Get with the times** 😉 I have but occasional I still slip and say 110 and 220 on accident its hard to break old habits;-) ---
**Author:** ![hcarvajal](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/hcarvajal/32/209279_2.png) [@hcarvajal](https://forum.nachi.org/u/hcarvajal)\ **Post date:** [October 1, 2014, 11:29am UTC](https://forum.nachi.org/t/where-did-110-come-from/90242/16 "2014-10-01T11:29:56Z")
> [@cbottger](#): > > Bert as long as they are picking on me they are leaving someone else alone;-) Hahaha very true Charlie. Bert ---
**Author:** ![belliott](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/belliott/32/57038_2.png) [@belliott](https://forum.nachi.org/u/belliott)\ **Post date:** [October 1, 2014, 11:38am UTC](https://forum.nachi.org/t/where-did-110-come-from/90242/17 "2014-10-01T11:38:23Z")
> [@cbottger](#): > > I have but occasional I still slip and say 110 and 220 on accident its hard to break old habits;-) That is exactly what I call it in my reports and who really cares on the other side of the paperwork. Not going to impress any Electrical Engineers anyway. ---
**Author:** ![jmckee](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/jmckee/32/211009_2.png) [@jmckee](https://forum.nachi.org/u/jmckee)\ **Post date:** [October 1, 2014, 12:28pm UTC](https://forum.nachi.org/t/where-did-110-come-from/90242/18 "2014-10-01T12:28:54Z")
---
**Author:** ![mlarson](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/mlarson/32/89225_2.png) [@mlarson](https://forum.nachi.org/u/mlarson)\ **Post date:** [October 1, 2014, 1:00pm UTC](https://forum.nachi.org/t/where-did-110-come-from/90242/19 "2014-10-01T13:00:05Z")
[Fascinating History of AC Power Distribution](http://edisontechcenter.org/AC-PowerHistory.html) ---
**Author:** ![sfetty](https://sea2.discourse-cdn.com/internachi/user_avatar/forum.nachi.org/sfetty/32/331195_2.png) [@sfetty](https://forum.nachi.org/u/sfetty)\ **Post date:** [October 1, 2014, 1:05pm UTC](https://forum.nachi.org/t/where-did-110-come-from/90242/20 "2014-10-01T13:05:48Z")
> [@cbottger](#): > > I have but occasional I still slip and say 110 and 220 on accident its hard to break old habits;-) Were they footers back then Charley?:D:D [Next page](https://forum.nachi.org/t/where-did-110-come-from/90242.md?page=2)