Author Topic: The real reason why North America uses 120v instead of 240v.  (Read 13498 times)

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Online BrianHGTopic starter

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The real reason why North America uses 120v instead of 240v.
« on: November 24, 2022, 06:30:13 pm »
If you wanted to know, here is why...


« Last Edit: November 24, 2022, 06:42:27 pm by BrianHG »
 

Offline IanB

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Re: The real reason why North America uses 110v instead of 220v.
« Reply #1 on: November 24, 2022, 06:37:23 pm »
Not to be picky or anything, but as per the video title and meter displayed in the thumbnail, North America uses 120 V, not 110 V...
 
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Online BrianHGTopic starter

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Re: The real reason why North America uses 110v instead of 220v.
« Reply #2 on: November 24, 2022, 06:43:32 pm »
Not to be picky or anything, but as per the video title and meter displayed in the thumbnail, North America uses 120 V, not 110 V...
I changed it, happy?
BTW, it used to be 110v and since it is a historical video...
 

Offline MikeK

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Re: The real reason why North America uses 120v instead of 240v.
« Reply #3 on: November 24, 2022, 06:55:04 pm »
Do countries that use 240V have two out-of-phase 120V lines (like the US actually has), or do they just have a single 240V line?
 

Offline Gyro

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Re: The real reason why North America uses 120v instead of 240v.
« Reply #4 on: November 24, 2022, 07:10:59 pm »
A single 230-240V Line and a Neutral.

Edit: That's unless you want to get into 3-phase supplies (typically not domestic, at least, not in the UK).
« Last Edit: November 24, 2022, 07:16:54 pm by Gyro »
Best Regards, Chris
 

Online jpanhalt

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Re: The real reason why North America uses 120v instead of 240v.
« Reply #5 on: November 24, 2022, 07:13:17 pm »
Two minutes of information at most compressed to 14 minutes of palaver.   Her enunciation is terrible and even as an American, she is harder to understand than our exalted leader Dave.  America is at 120V because that's where we started and its safer than 220-240 V.  More copper is needed, but lives are more important.
 
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Online Kleinstein

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Re: The real reason why North America uses 120v instead of 240v.
« Reply #6 on: November 24, 2022, 07:15:00 pm »
Do countries that use 240V have two out-of-phase 120V lines (like the US actually has), or do they just have a single 240V line?
Europe to a large part has 3 phase 230 V. So 3x230 V to ground and ~400 from phase to phase. Some smaller private installations only get 1 phase.
 

Online themadhippy

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Re: The real reason why North America uses 120v instead of 240v.
« Reply #7 on: November 24, 2022, 07:20:36 pm »
Quote
Do countries that use 240V have two out-of-phase 120V lines (like the US actually has), or do they just have a single 240V line?
in the uk generally you  get  240V (supposedly its 230,but theirs  a fudge factor a bit of tolerance so can legally be  anywhere from 216v to 253v,between live and neutral, or 3 phases 120 degrees apart that  gets you 415V between phases.
 

Offline TimFox

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Re: The real reason why North America uses 120v instead of 240v.
« Reply #8 on: November 24, 2022, 07:47:58 pm »
What I find interesting is that the normal domestic voltage in Japan is 100 V, but the country is split roughly in two between 50 Hz and 60 Hz distribution.
 

Offline Monkeh

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Re: The real reason why North America uses 120v instead of 240v.
« Reply #9 on: November 24, 2022, 07:55:36 pm »
More copper is needed, but lives are more important.

And yet more people still die of electrical shock and electrical fires in the US than in 230V nations. In 2017, 13 shock deaths were recorded in England. In 2020, 126 were recorded in work-place incidents alone in the USA.

Tell me again how your standards and accompanying attitudes are safer.
« Last Edit: November 24, 2022, 07:59:12 pm by Monkeh »
 

Offline IanB

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Re: The real reason why North America uses 120v instead of 240v.
« Reply #10 on: November 24, 2022, 07:57:18 pm »
Do countries that use 240V have two out-of-phase 120V lines (like the US actually has), or do they just have a single 240V line?

It is single phase 240 V, but wiring and appliances are supposed to assume that both line and neutral conductors are live, and each has to be equally insulated from any exposed parts that could be touched.
 

Online SiliconWizard

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Re: The real reason why North America uses 120v instead of 240v.
« Reply #11 on: November 24, 2022, 07:58:45 pm »
Do countries that use 240V have two out-of-phase 120V lines (like the US actually has), or do they just have a single 240V line?

It is single phase 240 V, but wiring and appliances are supposed to assume that both line and neutral conductors are live, and each has to be equally insulated from any exposed parts that could be touched.

Yep.
 

Online jpanhalt

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Re: The real reason why North America uses 120v instead of 240v.
« Reply #12 on: November 24, 2022, 08:08:50 pm »
More copper is needed, but lives are more important.

And yet more people still die of electrical shock and electrical fires in the US than in 230V nations. In 2017, 13 shock deaths were recorded in England. In 2020, 126 were recorded in work-place incidents alone in the USA.

Tell me again how your standards and accompanying attitudes are safer.

I would like to read your source.  What is it?  How were populations and usage matched?  For example, in Lesotho, 240 may be the standard, but the vast majority of the population doesn't use it as frequently as in America.
 

Offline Monkeh

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Re: The real reason why North America uses 120v instead of 240v.
« Reply #13 on: November 24, 2022, 08:12:04 pm »
More copper is needed, but lives are more important.

And yet more people still die of electrical shock and electrical fires in the US than in 230V nations. In 2017, 13 shock deaths were recorded in England. In 2020, 126 were recorded in work-place incidents alone in the USA.

Tell me again how your standards and accompanying attitudes are safer.

I would like to read your source.  What is it?  How were populations and usage matched?  For example, in Lesotho, 240 may be the standard, but the vast majority of the population doesn't use it as frequently as in America.

What does Lesotho have to do with the price of powdered milk on Mars? Are you somehow imagining England as an unelectrified backwater?

My sources are publications from the Office for National Statistics and the NFPA. I'm sure you can find them.
 
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Offline IanB

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Re: The real reason why North America uses 120v instead of 240v.
« Reply #14 on: November 24, 2022, 08:16:27 pm »
I'm sure I saw a video recently saying that electrical accidents have paradoxically been increasing in the years since the government introduced regulations with the intention of making things safer. But now I can't find the video with any search keywords. Either it is being hidden from the search results, or it got removed for being too alarming for people to see.

I think the premise was that anyone can now take a short training course and become "qualified" as an electrical installer, leading to all sorts of poor quality work. Whereas electricians have to go through years of training and apprenticeship to become properly qualified.
 

Offline DavidAlfa

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Re: The real reason why North America uses 120v instead of 240v.
« Reply #15 on: November 24, 2022, 08:19:24 pm »
Because of inches, feet, pounds and all that standard aberration.
But they know very well what 9mm is  :-DD
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Online jpanhalt

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Re: The real reason why North America uses 120v instead of 240v.
« Reply #16 on: November 24, 2022, 08:24:55 pm »
@Monkeh,

If you have so many sources, it should be easy for you to cite at least two comparisons.  So?
 


Online jpanhalt

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Re: The real reason why North America uses 120v instead of 240v.
« Reply #18 on: November 24, 2022, 09:09:02 pm »
Neither of those links compare death from 120V to 240V.

Please provide your data/links that  show electrical shock from 240V in not more lethal than shock from 120V.
 

Offline TimFox

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Re: The real reason why North America uses 120v instead of 240v.
« Reply #19 on: November 24, 2022, 09:14:23 pm »
Because of inches, feet, pounds and all that standard aberration.
But they know very well what 9mm is  :-DD

The Volt is a metric unit.
When Britain adopted 220 or 240 V, they were not yet metric.
When Japan adopted 100 V, they were already metric.
I see no correlation.
« Last Edit: November 24, 2022, 09:48:31 pm by TimFox »
 

Offline Monkeh

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Re: The real reason why North America uses 120v instead of 240v.
« Reply #20 on: November 24, 2022, 09:21:46 pm »
Neither of those links compare death from 120V to 240V.

Please provide your data/links that  show electrical shock from 240V in not more lethal than shock from 120V.

I didn't say they did, because the data isn't broken down that way.
 

Online bdunham7

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Re: The real reason why North America uses 120v instead of 240v.
« Reply #21 on: November 24, 2022, 09:22:06 pm »
And yet more people still die of electrical shock and electrical fires in the US than in 230V nations. In 2017, 13 shock deaths were recorded in England. In 2020, 126 were recorded in work-place incidents alone in the USA.

That doesn't really add up as an argument.  Workplace safety regulations and the relative compliance with might vary quite a bit, for example.  You don't know what voltage the workers were shocked at, either--I'm confident a good proportion were not electrocuted by 120V.  There are HVDC solar systems, 480VAC/3-phase (and higher) systems, primary high voltage (3800-14,400V), microwave oven transformers (2 deaths locally that I know about and I'm referring to people repairing the ovens, not the fractal wood burning idiots) and so on.  I doubt you are going to be able to really tease out the safety advantage (if any) of 120V.  Perhaps we need to shock some sheep or something.

When I read reports of these incidents, my reaction generally is one of two things:  1) Wow, what a dumbass! (not necessarily the victim) or 2) Wow, that's a pretty unlikely freakish accident!  90% are probably #1.  Older houses, especially attics and crawlspaces, along with barns, seem to be the among the most dangerous places.
A 3.5 digit 4.5 digit 5 digit 5.5 digit 6.5 digit 7.5 digit DMM is good enough for most people.
 

Offline Monkeh

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Re: The real reason why North America uses 120v instead of 240v.
« Reply #22 on: November 24, 2022, 09:28:58 pm »
And yet more people still die of electrical shock and electrical fires in the US than in 230V nations. In 2017, 13 shock deaths were recorded in England. In 2020, 126 were recorded in work-place incidents alone in the USA.

That doesn't really add up as an argument.

But it's the available data to work with. I chose not to go with the more approximate total figure (upwards of 300) due to lack of motivation to find the specific source. Where's the data to suggest 120V systems and, as I originally stated, the accompanying attitudes regarding safety, are in fact safer?

Teasing out good numbers for fires will be even harder - US statistics are as ever hard to locate, and there's no ICD10 code regarding origin of fires (that I know of), they'd all come under X00.
« Last Edit: November 24, 2022, 09:36:10 pm by Monkeh »
 

Online SiliconWizard

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Re: The real reason why North America uses 120v instead of 240v.
« Reply #23 on: November 24, 2022, 09:48:49 pm »
110V was the standard in most european countries before switching to 220V (which became 230V to 240V depending on the country.)
Sure switching to a higher voltage allowed lower currents, so lower losses. Beyond that, I think there were studies showing that 110V was actually more dangerous.
But people in the US were usually told the opposite.

While, for the same impedance, the current through your body would be twice as high with 220V as opposed to 110V - which was the main rationale invoked - and sure, the higher the current, the higher the risk. Right?

Now in those ranges, typically a few tens of mA unless your skin is very wet, it's mostly energy that matters, so the duration is key. I have consistently heard that on average,  for people with no specific health condition, 220V was more likely to trigger a withdrawal reflex (thus a very short exposure), while 110V was more likely to trigger muscle tetany (thus longer exposure.) I have no paper right now to back this up though.

The real reason, in both cases though, is just likely to be purely economical.
All I can draw from my own experience is that I sure did get shocked quite a few times with 220V in my life and always got a strong withdrawal reflex with no more consequence than an elevated heart rate for a couple minutes.

 

Offline rstofer

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Re: The real reason why North America uses 120v instead of 240v.
« Reply #24 on: November 24, 2022, 10:04:17 pm »
Because of inches, feet, pounds and all that standard aberration.
But they know very well what 9mm is  :-DD

And 5.56mm and 7.62 mm and 106mm.  Some of the long range guys are familiar with 6.5mm as in 6.5x284 Norma.

https://weaponsystems.net/system/1341-106mm+M40
The M40 was usually Jeep mounted on an M151A1C

And people think we don't use metric...
 


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