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Chuck Wintle
02-28-2014, 5:19 PM
I was just thinking about the north American and the European electrical grid and do not understand how we ended up with 120vac and 60 Hz and in Europe is 220vac at 50hz. Why is there a difference in the electrical distribution?

Kev Williams
02-28-2014, 5:35 PM
I was just reading about this a couple months ago, because I ordered my laser from China wired for 220, mistakenly thinking I'd get it wired for US 220. It's not- and I'm running it and all the accessories via a 3000 watt voltage converter...

Best I can recall from what I read was, someone across the pond decided single-line 220v is more efficient-- although more deadly, which is why we chose to go with 110v and 2-line 220v. And 50hz was decided on over there simply because it fit in with the metric system. My Laser and accessories are all 50hz, but run fine with the 60hz converter...

Mike Henderson
02-28-2014, 5:39 PM
From everything I read, it just developed that way. There's no great reason that either would be preferred.

A 50 Hz induction motor will run slower than a 60 Hz induction motor (same number of poles) and it will be somewhat larger because of the additional iron needed. For long distance power transmission, 50 Hz is probably a bit better. Don't know if this is a big factor, but a 50 Hz generator will run slower than a 60 Hz generator.

When reading about the history of the development of power systems in different countries, it appears that Europe decided to use 50 Hz and the US decided to use 60 Hz. Nobody worried about standardization because the systems were isolated and people didn't travel with their electrical devices back then.

In any case, it'll never be standardized.

Just a little side note, Japan has both 50 and 60 Hz power in their country.

Regarding the differences in voltage, my opinion is that the US system is superior. For single phase household power, the maximum voltage to ground is 120V. To get 240V you have to touch two hot wires simultaneously. The advantage of the European 220V system is that greater power (volts times amps) can be supplied on a single circuit than on 120V, given the same wire size. But, today, most of the appliances are low power demand, which favors the 120V system.

There's also the question of whether the distribution wiring should be grounded at one place (as it is in the US system). Some European systems do not (or, at least, did not some years ago) have a ground in the distribution wiring. If everything was good, you could touch one of the wires and not get shocked because there was no return path through ground. The problem they discovered is that you can get a ground connection inadvertently (maybe a wiring mistake) and it would not show up as a problem. But if someone then touched the right wire, they would get shocked with 220V. My opinion is that it's better to put in a ground, and if you have a wiring mistake (hot to ground) it will show up immediately by tripping a breaker.

Mike

Myk Rian
02-28-2014, 5:52 PM
Best I can recall from what I read was, someone across the pond decided single-line 220v is more efficient--
And after our son got home from his Army tour in Germany, all the ground lugs on my extension cords, and some tools went missing.

Jeff Erbele
03-01-2014, 2:54 AM
I was just thinking about the north American and the European electrical grid and do not understand how we ended up with 120vac and 60 Hz and in Europe is 220vac at 50hz. Why is there a difference in the electrical distribution?

The simple answer is, its complicated :eek:

In "Utility Frequency" http://en.wikipedia.org/wiki/Utility_frequency
in the section on History, it states:
Though many theories exist, and quite a few entertaining urban legends, there is little certitude in the details of the history of 60 Hz vs. 50 Hz.
http://en.wikipedia.org/wiki/Utility_frequency#History

From the "War of Currents" http://en.wikipedia.org/wiki/War_of_Currents
the results were:
In Europe, Siemens & Halske (http://en.wikipedia.org/wiki/Siemens_%26_Halske) became the dominant force. Three phase 60 Hz at 120 volts became the dominant system in North America while 220-240 volts at 50 Hz became the standard in Europe. http://en.wikipedia.org/wiki/War_of_Currents#Competition_outcome

There is no best system. The best frequency is a compromise between contradictory requirements.
http://en.wikipedia.org/wiki/Utility_frequency#Operating_factors

Steve Baumgartner
03-01-2014, 9:47 AM
I think Mike hit on the key point: in the early days there was no such thing as a regional power grid let alone national or international, and there were few portable electrical devices. Each electrical entrepreneur was free to select whatever voltage and frequency they preferred, for whatever reasons. There have always been safety and efficiency tradeoffs, and each local supplier made their own choices. Edison actually preferred DC, and you can still find his powerhouses in many cities, long since converted to other purposes.

But as wider distribution came into being and more devices were invented, it became necessary to standardize. The standards were set by whoever was dominant in each area at the time. The largest players in the US and in Europe just happened to have chosen different systems, and since there was no interconnection saw no reason to change.

Ironically, today it is less important than in the past because so many electronic devices actually run on low-voltage DC internally and can be plugged into any AC voltage and frequency.

Jeff Erbele
03-02-2014, 3:31 AM
It is fairly certain there will never be a world wide, standardized, electrical frequency, and never a standardized voltage, and never AC/DC making the other obsolete.

Having been employed by GE twice, Westinghouse once and then for a spin-off of Circle Bar W, I can say with utmost certainty, "The Current Wars" never really ended in sentiment and had long lasting effects over 115 years later. On the job sites, one could cut air with a knife when hard hats of opposing companies (both contractors) had to cross paths / work spaces and events related to the job.

Beside the point and irrelevant to the Hz topic, sharing my experience and sentiment as an employee of both companies:

* Westinghouse sold or spun-off everything and became Via Com.

* GE was the better employer by light years (x a factor of 10 squared plus infinity & beyond & then some, plus a little more and with a gratuity and a sincere thank-you for your efforts to boot), and exists today.

Still when I had no choices, I gave Westinghouse, later Eastern Electric, later Grand Eagle, my heart and soul, and they put bread on my table.

Mean while circumstances were such that I had to turn down repeated offers from General Electric whom I really wanted to work for.
You know when you are good at what you do.
You know you are really good at what you do when they call you; further you turn them down and they call again, and again years later.
You know you are great at what you do when a company you never worked for, Siemens, calls you.

What I did was learn how machines and machinery worked, with education as a mechanic, hydraulics, welder, advanced machinist and basic electrical knowledge, trouble-shot, manufactured, fabricated or repaired them in industry. Later on the job, learned static & dynamic balancing, non-destructive testing, predictive and preventative maintenance. Basically how to prevent me from fixing it in the first place, and/or tell you when you are going to need me to fix it. That knowledge is invaluable. Multi-talented in relationship to integrated and complex systems is of value. Frankly the high demands, non-stop, emergency and extreme hours wore me out; to a frazzle. I had something to do with when you turn on the switch, power is delivered as you expect it, or you turn on your facet, or you open a can of soup... stuff comes our right.

The fact is circumstances for corporate employers are business decisions, and those effect employees.
After 6 corporate terminations, no fault of mine, I determined I had no desire to work for others ever again and decided I would not, then I did again while I figured out how not to and eventually became self-employed. It took 4 attempts, two thwarted in a divorce, but finally things are clicking successfully.

Rod Sheridan
03-02-2014, 2:28 PM
I was just thinking about the north American and the European electrical grid and do not understand how we ended up with 120vac and 60 Hz and in Europe is 220vac at 50hz. Why is there a difference in the electrical distribution?


Well, in Ontario we didn't end up with 60Hz or 50Hz, we had 25Hz.

The province was converted between 1949 and 1959 which was an enormous project.

A couple years ago I scrapped a motor that bore a HEPCO (Hydro Electric Power Corporation of Ontario) rerate nameplate from 25 to 60Hz. The motor had run a 3 cylinder air compressor in a automotive service center since some time before 1958 which was the date on the rerate plate.

In the 1980's I was a manager for a custom power equipment manufacturer, and we built some 25 Hz rectifiers for electric mine locomotives, the mines still had 25Hz power.

The flicker from the incandescent lighting was very visible.....
Regards, Rod.

Rod Sheridan
03-02-2014, 2:37 PM
I was just thinking about the north American and the European electrical grid and do not understand how we ended up with 120vac and 60 Hz and in Europe is 220vac at 50hz. Why is there a difference in the electrical distribution?

The voltage issue is simple, in the US, Edison was using DC so the voltage had to be used, at the voltage it's produced at.

Edison invented the Edison circuit (multi-wire branch circuit) which provided 2 X 120 volt DC feeds of opposite polarity with a common return wire (neutral). This allowed 120 and 240 volts DC.

Of course DC isn't great at low voltages, as the line losses are too high so generating stations had to be located every few blocks.

George Westinghouse teamed up with Nicola Tesla (inventer of the polyphase system) and the resulting AC system was the deathknell of Edison and his DC.

Edison did fight back, and invented the electric chair, using AC of course, and coined the term "Westinghoused" to describe electrocution. Edison even had shows where they electrocuted cats, dogs and horses on stage, one famous event was the electrolution of an elephant.

The first time I saw that video was at an IEEE event, you can find it on Youtube now.

Europe went with 380 volts 3 phase, so you have 220 volts to neutral, which is what houses have, one phase of the 3 phase system plus a neutral.

regards, Rod.

Howard Garner
03-02-2014, 3:13 PM
[QUOTE=Rod Sheridan;2233860]The voltage issue is simple, in the US, Edison was using DC so the voltage had to be used, at the voltage it's produced at.

Edison invented the Edison circuit (multi-wire branch circuit) which provided 2 X 120 volt DC feeds of opposite polarity with a common return wire (neutral). This allowed 120 and 240 volts DC.

Of course DC isn't great at low voltages, as the line losses are too high so generating stations had to be located every few blocks.



Interesting, in 1962 I live in a apartment in lower Manhattan that was still DC

Howard Garner