European - US Voltage levels
European - US Voltage levels
(OP)
Gentlemen,
Maybe this question has been raised before.
What are the reasons for the differences in voltage levels between the US and Europe - 4.16 kV (US) vs. 3.3 kV (Euro.) and 7.2kV (US) vs. 6.6 kV (Euro.)? Does it have anything to do with the 50 Hz. vs. 60 Hz. frequency differences?
Regards,
Raisinbran
Maybe this question has been raised before.
What are the reasons for the differences in voltage levels between the US and Europe - 4.16 kV (US) vs. 3.3 kV (Euro.) and 7.2kV (US) vs. 6.6 kV (Euro.)? Does it have anything to do with the 50 Hz. vs. 60 Hz. frequency differences?
Regards,
Raisinbran






RE: European - US Voltage levels
Bill
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"Why not the best?"
Jimmy Carter
RE: European - US Voltage levels
There is really no rhyme nor reason to it, it is a result of legacy systems and the ability of suppliers to easily and inexpensively adapt to their neighbors as electrification expanded after WWI and grids started connecting to each other. Adaptation was irrelevant and unnecessary "across the pond" between Europe and America, and as Asia electrified, they imported more systems from Europe and so ended up adopting similar standards.
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RE: European - US Voltage levels
RE: European - US Voltage levels
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If we learn from our mistakes I'm getting a great education!
RE: European - US Voltage levels
I'd attach little or no inference to where they have ended up; they got to their present state by meeting the differing needs of their respective environments.
BTW: if you want to see real divergence, look at CCITT vs Bell System standards some day...
RE: European - US Voltage levels
I thought that was a really weird voltage level and asked how he could know it was just that voltage. 'They all are' he answered.
When I asked why one would chose such an odd voltage, he had no answer. He thought it was a perfectly normal and natural voltage. I still have no idea why the last 160 volts on top of the 4 kV were considered important. Covering a 4 % drop instead of the 10 % used in Europe? If so, it seems to be a more 'researched' percentage than the European 10 %.
Gunnar Englund
www.gke.org
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100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: European - US Voltage levels
Muthu
www.edison.co.in
RE: European - US Voltage levels
12.47kV -----> 7200V L-N, etc.
Multiple of 11 has always been a favorite trivia question in Europe and Asia, but there is no real technical reason. Although more common voltages 415V or 400V, 230V, 240V or 400kV are not multiple of 11.
Rafiq Bulsara
http://www.srengineersct.com
RE: European - US Voltage levels
Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...
RE: European - US Voltage levels
RE: European - US Voltage levels
415V is a utilisation voltage - the distribution voltage was 440V, which does have the '11' factor. The newer 400V standard is the result of European
meddlingharmonisation. I seem to remember that 400kV was the limit of proven technology at the time when the 400kV system was being built, and that is why it doesn't fit the pattern. Difficult to explain 275kV though!----------------------------------
If we learn from our mistakes I'm getting a great education!
RE: European - US Voltage levels
That is the origin of 4160V as a voltage as I know it. I was in school when our system changed over from 2400V to 4160V.
Some may note that 2400:4160V is exactly 20 times the now standard 120:20Volts. BUT, most of the 2400:4160V distribution was long gone before 120:240 became a standard. Go figure.
Bill
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"Why not the best?"
Jimmy Carter
RE: European - US Voltage levels
There are still a few remnants of 150V in the US National Electrical Code (NEC) with respect to grounding requirements.
Of course more people have been electrocuted (by definition they died) by 120V than any other voltage in the US. The lowest documented lethal voltage is now believed to be ~60V. Again multiply it by 80% and round off to 50V to become more or less the new "safe voltage" as reflected in many NEC and OSHA rules.
RE: European - US Voltage levels
Appliances were rated for 110 Volts. Then for five years they were rated at 112 Volts. Five years later new appliances were rated at 115 Volts, the 117 Volts for five years.
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: European - US Voltage levels
Alan
"The engineer's first problem in any design situation is to discover what the problem really is." Unk.
RE: European - US Voltage levels
Thank you all very much for the responses. Although no definite answer has been determined, the information that you provided was very interesting. I guess that variety truly is the spice of life.
Regards,
Raisinbran
RE: European - US Voltage levels
Commercial Electric distribution was first done by Edison and his Manhattan DC lighting system was opened in September,1882.Edison took 100V as the voltage for his incandescent lamps.( Why 100 V?Round number,safe electrical voltgae to handle,but high enough to save copper in conductors)But it soon became clear that at the fag end of street the lamps were not burning well due to voltgae drop in line.Edison had to raise the generator voltage to 110 V ( there by distribution voltage became 110V!)to take care of the voltgae drop in line.To save copper, Edison raised the voltage to 220 V by adopting three wire Dc system .
When in 1886, first AC power distribution was installed at Great Barrington,Massachusets, Westinghouse and Stanley adopted 500 V as generator voltage 3 KV as transmission voltage and finally 100 V as distribution voltage.When first 3 phase Ac line was put up by Siemens to connect Lauffen with Frankfurt,generator voltage was 55V( half of 110V) and transmission was at 15Kv to be raised to 25 kV later.
According to clause 3.2.6 of Red book,(IEEE 141-1993),later distribution and transmission voltages were developed as multiples of 110
ie utilisation voltages of 110,220,440,550 V and distribution voltages of 2.2,4.4,6.6,13.2 Kv and transmission voltgaes of 22,33,44,66,110,220Kv
In US to keep the utilisation voltage same at full load, supply voltage was kept little more high ie 115 V.Then a new series occurred ie utilisation voltages of 115,230,460,575 V and distribution voltages of 2.3,4.6,6.9,13.8 and transmission voltages of 23,34.5,46,69,115,138,230 Kv etc,
As a result of continued problems with the operation of voltage sensitive lighting equipment and voltgae insensitive motors on the same system and the development of the 208Y/120V network system, supply voltages were raised again to multiples of 120 V
120,208Y/120,240,480,600V as utilisation voltages and 2.4,4.16,2.4,4.8,12,12.47Y/7.2 Kv as distribution voltages.