120V standardization

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DavidFY

New member
Location
Spain
Hello


*Note: In case you do not fully understand, tell me to translate better.


I am a Spanish electrician, residing in Spain, and I have some curiosity about the standardization of American voltage.


In my country had always used 127 V for domestic use, but over time that has passed, some countries insisted that much to install 220/380 V, 127/220 V instead


In the 80s in Germany became the IEC60038 standard, which recommends that all work to 230/400 V, but does not justify the choice of this tension.


What I really want to find out is whether there is a similar rule to recommend 120 V (120/208 V).


The short history of my country is that it began using voltages of 110-127 V, but in 1910 is approximately standard 127/220 V and 380V shortly industries and small plants. In the years 60-70s starting to become popular single-phase 220 ??V and 380 V three-phase outside the industry, but still majority 127/220 V. In the years 70-80s some companies change the voltage, changing the transformer 220/380 V distribution, but others maintain 127/220 V. And now with both increased distributions to European voltage 130 V (133 exactly), 230 V, 400 V.


Although I am aware that as an electrician with more voltage is needed less thick wire, I think it is right what they have in the US and other countries, 120 volt. In my country we have distributions of 130/230 V and 230/400 V, and have had the opportunity to interact with both, and this experience has shown me that working with 230/400 V, if only one phase is much more dangerous with 120/208 or 130/230 V. for this reason alone, the world should be standard voltage 120-130 V.


I honestly do not know how to be the first US power in the world has not become more popular proper voltage versus European dangerous voltage. The 400 V should not have ever come out of the industry, imagine him in a home? It is not uncommon in my country.


I also read on a website that "the distributions of 120 V (240 V single-phase or three-phase 208) can not make a distribution network, while a 230/400 V distribution can reach great distances, and that 120 V transformer is needed in each building."
With more voltage you can go further, but that this is very exaggerated, because in Spain we have assembled networks 130/230 V to 230/400 V concept (phase transformer up to 1000 kVA, max aerial wired networks of 3x150 mm2+95mm2 and underground with 3x240 mm2+150mm2) and it is possible to supply a number of points with a distance respecting brownouts. In Europe measured the thickness of copper in square millimeters, diferent to AWG.


I show a picture of a meter of 127 V 50 Hz:
http://www.foroelectricidad.com/download/file.php?id=1970


And old 3-wire meter, identical system to that used in their homes with two phases and neutral:
http://www.foroelectricidad.com/download/file.php?id=1969


I hope I have not violated any rules of presentation, as it can hab?rseme skipped some text in English.
regards
 

GoldDigger

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Staff member
Location
Placerville, CA, USA
Occupation
Retired PV System Designer
The US power distribution started out with anywhere from 108 to 125 in a split phase (single phase) configuration with line to line voltage being twice the line to neutral voltage
The distribution network would indeed need a transformer for each small cluster of houses. Perhaps with three or more transformers per block. In rural areas there would be one transformer for each customer.
The distribution would most often be in two stages with Medium Voltage (MV) as the primary to the customer transformers and HV to substations which fed the MV lines.
There is no particular rational reason that makes 120 better or safer, it just became s standard compromise among competing systems in the early days.
Large motors and heating appliances would use 240 because it was better suited to high power loads.
 

kwired

Electron manager
Location
NE Nebraska
The US power distribution started out with anywhere from 108 to 125 in a split phase (single phase) configuration with line to line voltage being twice the line to neutral voltage
The distribution network would indeed need a transformer for each small cluster of houses. Perhaps with three or more transformers per block. In rural areas there would be one transformer for each customer.
The distribution would most often be in two stages with Medium Voltage (MV) as the primary to the customer transformers and HV to substations which fed the MV lines.
There is no particular rational reason that makes 120 better or safer, it just became s standard compromise among competing systems in the early days.
Large motors and heating appliances would use 240 because it was better suited to high power loads.
And then larger motors and equipment came about and doubling the voltage to 480 was even better suited, yet one could make this equipment "dual voltage" to run on 240 or 480 so it would work in the new plant with 480 volt system or the old plant with existing 240 volt system. 208 and 277 volts were just side effects of three phase wye systems and people eventually decided to make equipment to operate on those voltages just because they were available in many places.
 

junkhound

Senior Member
Location
Renton, WA
Occupation
EE, power electronics specialty
Edison's carbon/thread filaments tended to break when they got more than a few inches long but they could take about 1 amp before burning out too fast.

Turned out the length they would start to break was about 100 ohms, so 100V at the light bulb, add 10 V for line drops, and Tom used +/- 110V dc generators all over town.

By the time George W and Nick T showed ac was better, there were lots of 100 V light bulbs out there, so 60 Hz 110Vac was the distribution voltage of choice. Don't forget that NYC was dc till the 1950 with some hldouts till 2009, and many table radios used the 'all American five' tube sets that used 100vdc or 110Vac input

In Europe, shortly after Tom E's light bulb, Sandy J found out that tungsten filaments were better than carbon/thread and they could be made to run on 250V easily, thus Germany started with 200V ac or thereabouts. Plus, 60Hz is not a nice 'metric' number, so 50Hz was used; rest of Europe followed that lead.

As I grew up, recall tool and appliance nameplates went from 110Vac to 115Vac, to 117Vac for awhile, till it has finally settled on 120 Vac. I do not recall all the history of the 110 Vac to 120 Vac transitions, probably some weenies on an IEC board had some reasons to help their companies bottom line over time.

No idea why Japan uses the same outlets as USA yet line voltage is 100 Vac? Probably some export reasons post WW2 but have never researched that question.
 

growler

Senior Member
Location
Atlanta,GA
I think it would be great if there was a standard electrical system used all around the world, we could also use the same stardards of weights and measures, drive on the same side of the road and maybe even speak the same language ( I vote for pig latin, hard to argue in pig latin).

The thing is that it's just not going to happen.
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
Personally, standardizing 120 volts as a distribution voltage was a massive mistake. More than double the copper is used, in addition the heavy, energy wasting 480-208 volt dry type transformers needed in each building. Because 120 volts cant ravel as far, more distribution transformers are used. Without a doubt as a whole the European system is more efficient. However, its not all good or bad. Having 230 volts phase to ground is much more hazardous than 120 or 150 volts.



Years ago I did propose a distribution system that should be employed in the US and through out. From crunching the numbers I came to this as the most optimal considering all perspectives:

A. For residential and light commercial: 240Y/139

Solid grounded XO, 4 wire (H-H-H-G) no neutral, (just an equipment ground). All loads are connected phase to phase. Standard utilization equipment is 240 volts 60 hertz. Small to medium (1HP-60HP) 3 phase Motors are 6 lead connected in delta. Single phase customers can also be fed from a 240 volt center tap transformer need be. The advantage of both these system is that voltages are always below 150 volts to ground nominal making them far safer for both users and amateur DIYs. No neutral means no mix up between grounded and grounding conductors, no over voltage either from one getting broken either.

B. For large commercial, light industrial and high rise residential: 415Y/240

5 wire (H-H-H-N-G) with N&G both separate all the way back to the source (TN-S). Standard 240 volt utilization equipment and lighting is re-used, simply hooked phase to neutral. Because voltages exceed 150 volts to ground nominal; all 240 volt general use circuits (like those feeding receptacles) shall have 5 or 30ma GFCI protection. The same motors above wired in delta are reconfigured to wye as to run on 415 volts. Larger motors say 25 to 100HP and above can be configured in delta but rated 415 volts. Highbays, parking lot lights, have the option of being rated 415 volts (like 480 volt units today).


Because this system is reserved only for larger applications there is more likelihood this system will be serviced by qualified personal making the higher voltage to ground and complexity a lesser issue. Since 208Y/120 and 480Y/277 are now consolidated into a single system design its both easier and cheaper. No energy is waited on stepping down voltage. Even though 415 volts uses slightly more copper than 480 volts feeding motors, its offset many times over eliminating 208Y/120 and its associated step down transformers.

C. Large industrial, Stadium/Roadway lighting ect: 720Y/415

5 Wire TN-S (or 4 wire where only 720 volts is needed). Qualified personal only. The medium to large motors (25 to 100HP and above) connected in 415 volts delta are now reconfigured to 720 volts Y. Lighting ballasts and led drivers rated 415 volts are connected phase to neutral. Where 240 volts is needed either an auto or isolation step down is used or the building is given a secondary service.


D. For Very large industrial/special applications: 1000Y/577 For the few applications that need this. 1000 volts phase to phase is the maximum at which a service can be considered LV holding to LV standards.



E. Ungrounded, Peterson coil or High resistance versions of: 240, 415 and 720 volts.
Where critical process takes place with qualified personal the above systems have the option of being designed to operate with a grounded phase without the loss of service continuity.
 
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suemarkp

Senior Member
Location
Kent, WA
Occupation
Retired Engineer
With all the safety technology available today, I'd say the choice of voltage doesn't matter that much (as long as its in the 100V - 300V to ground range). What seems more important is what your neighbors have. Traveling from country to country and having to carry transformers for all your electrical equipment would be a pain. I would standardize by continent, to whatever standard is chosen. And this includes grounding scheme in addition to frequency and voltage.

If you're in Spain, I'd try to match what France has, and hopefully that matches Germany and all the rest of Europe.
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
With all the safety technology available today, I'd say the choice of voltage doesn't matter that much (as long as its in the 100V - 300V to ground range). What seems more important is what your neighbors have. Traveling from country to country and having to carry transformers for all your electrical equipment would be a pain. I would standardize by continent, to whatever standard is chosen. And this includes grounding scheme in addition to frequency and voltage.

If you're in Spain, I'd try to match what France has, and hopefully that matches Germany and all the rest of Europe.

Most of Europe was 220/380 while the UK was 240/415 50Hz. The IEC set about to create 230/400 as a harmonization, as well as color codes. Brown, Black and Gray are phase, blue neutral and green/yellow earth. Norway and Belgium are interesting in that Norway is 230 volts IT, while Belgium is 133/230Y. Basically both systems connect all loads phase to phase. The Belgian system IMO is the safest.


FWIW, there are rumors of a global plug that will eventually supersede all know receptacles. Brazil is the first to try it out:
 

ActionDave

Chief Moderator
Staff member
Location
Durango, CO, 10 h 20 min from the winged horses.
Occupation
Licensed Electrician
Personally, standardizing 120 volts as a distribution voltage was a massive mistake. More than double the copper is used, in addition the heavy, energy wasting 480-208 volt dry type transformers needed in each building. Because 120 volts cant ravel as far, more distribution transformers are used. Without a doubt as a whole the European system is more efficient. However, its not all good or bad. Having 230 volts phase to ground is much more hazardous than 120 or 150 volts.



Years ago I did propose a distribution system that should be employed in the US and through out. From crunching the numbers I came to this as the most optimal.....
What's the going rate, cost per square mile on rewiring an entire continent?
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
What's the going rate, cost per square mile on rewiring an entire continent?


Not all that much, this would be done gradually as older equipment hits end of life. Most of the existing distribution equipment will be re-used as much as possible. But roughly $50,000-$1,500,000 added cost spread out over a 50 year period. :p


An exiting home for example would cost about $1000 to $4500 to convert at once. A new home would cost several thousand less once a standard of plug goes into mass production since the needed circuits will halve. POCOs build 3 phase banks with 120.240 pole pigs. By rearranging the leads a 208Y/120 bank can be turned into a 416Y/240 output without changing anything. In the short run there will be added cost no doubt, but in the long run it will come out cheaper. Obviously start with new construction while old construction is phased in gradually. :angel:







But I get where your coming from. The real cost isn't the conversion, rather the amount of 120 and 480 volt equipment that would that would have to become obsolete over a 40-60 year period is painfully expensive. I think that's what holding us back over anything else.
 
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