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W0RLI > INFO 07.07.02 21:53l 137 Lines 5772 Bytes #999 (0) @ WW
BID : 5076W0RLI
Read: DB0FHN GUEST
Subj: Re: Again: 110v vs 230v ...
Path: DB0FHN<DB0ZWI<DB0MAB<DB0FBG<DB0CHZ<OK0PKL<OK0PPL<RZ6HXA<SP7MGD<WB0TAX<
N7FSP<KB6LE<KB6LE<W0RLI
Sent: 020707/0720 20599@W0RLI.OR.USA.NOAM
Just a couple notes about line voltages / frequencies.
In Japan, and probably other places in Asia, one can find
100 volt mains. My TS-930, for example, is a Japanese version,
and requires a step-down autotransformer here in the US to
bring the voltage down to 100V.
I worked in an old factory building for awhile which had been
used during WW-II for glider construction. That building
had three different rooms for incoming power. One was the
usual 115/230 plus 270 three phase. Another had two phase
(90 degree phase angle) 100 volts 25 Hz. Nobody knew exactly
where it came from, but it was live. The third had 400V
DC power, supplied by the street car company. The story
was that these were all needed for various old shapers and
vertical mills that had been scavanged from here and there
and put back into service for the war effort. There was also
400 Hz three phase from a large MG set, but this appeared
to be newer gear, probably circa the middle or late 1940s.
This building also had several cats, and a flock of English
sparrows in residence. The cats were needed: I often
saw mice and rats run down the hall. This was in St. Paul,
Minnesota in the middle 1960s. There were several other
buildings in the complex, but the old glider factory was the
most interesting :-)
Recently my power company made a small adjustment to
the local distribution system to bring the line voltage to
exactly 117 volts. It had been 109-110 for several years.
Incandescent lamps became noticably brighter. To bring
Einstein back into things (from another thread), there is
that nice fourth power law about radiated energy vs.
temperature.
Incandescent lamps are a whole nother thread ...
Are the "compact flourescent" lamps with semiconductor
starter/balast built-in becoming common anywhere else
in the world? There has been quite a drive to get people
to use them here in Oregon. The power company was even
giving away sample early this year ...
--
... Hank
Hank: http://horedson.home.att.net
W0RLI: http://w0rli.home.att.net
<DC2FR@DB0GV.#HES.DEU.EU> wrote in message news:672DB0GV02H...
>
>
>
>
> Hello packeteers worldwide,
>
> Sorry at all - late I discovered the actual discussion about the different
> mains voltages 110v vs. 230v ... the reasons, advantages and disadvantages
> ("INFO" is not so an usual board here in Germany).
>
> This is a very interesting discussion, indeed - but also taking a lot of
> time to read all the detailed statements, hi ... !
>
> So, let me add some aspects to this interesting topic.
>
> I have read in some bulletins, 110v 60 Hz would probably be more dangerous
> than 230v 50 Hz. This is definitively not true - moreover, it`s absurd.
> Simple reason: the higher the voltage - the higher the current - the higher
> the danger causing heart fibrillation! AC currents more than 30 mA can cause
> heart fibrillation, more than 50 mA mostly cause, and more than 80 - 100 mA
> surely cause heart fibrillation! 50 or 60 Hz - this doesn`t matter !
> Decreasing effects can only be expected at much higher frequencies.
> A scientific examination says, at 400 Hz heart fibrillation treshold
> would be 6times higher, at 1000 Hz 14times higher compared with 50 Hz.
>
> This is the reason why high frequency AC currents (in the Kilohertz range)
> are significantly less dangerous than power frequencies of 50/60 Hz.
>
> 220 volts - 230 volts - 240 volts ...
> -------------------------------------
>
> In the "continent countries" of Europe, 220/380 v (220v single phase -
> 380v three phase) was the dominant mains voltage in the past.
> However, in the UK countries (and perhaps Australia ?) 240/415v was usual.
> So - the new 230v/400v system is a harmonization compromise, to unite
> the different mains voltages in Europe.
>
> Railroad aspects ...
> --------------------
>
> In Europe, there are four different systems for electric railroads:
>
> 1500 v dc Netherlands, parts of France
> 3000 v dc Italy, Belgium, Parts of Poland/Czech republic/Russia
> 15000 v ac 16 2/3 Hz Germany, Austria, Switzerland, Sweden, Norway
> 25000 v ac 50 Hz France (most parts), Luxemburg, Spain, Portugal, UK,
> Greece, parts of Poland / Czech Republic / Russia
>
> The 25 kvac 50 Hz system is now the mostly efficient railroad system -
> preferred by countries which started later with railroad electrification.
>
> DC systems have disadvantages due to high current draw in the catenaries,
> so thick and heavy overhead cables are needed, just as a lot of feeding
> stations along the railroad line.
>
> The German (and also Austrian, Swiss ...) 16 2/3 Hz system is a very old
> system founded in the year 1912! Reason was the following: for railroad
> traction preferrably used were series commutator motors (like DC motors),
> because of their advantages high torque - easily control - good efficiency.
> BUT: problems occur when supplying great commutator engines with 50 Hz
> AC current due to "transformation voltages", phase shifting and so serious
> commutating difficulties. So, a lower frequency was choosen to minimize
> these problems. A good compromise was found in 16 2/3 Hz as the common
> frequency 50 Hz divided by three.
>
> The system was very successful - so it is used until today, although in
> modern locomotives throughout now three phase asynchronous motors are
> used instead of commutator engines, driven by power electronics inverters.
> So, now the electric system driving the traction motors becomes completely
> independent of the mains system ... another aspect to favorize the 50 Hz
> (25.000v) system for new railroad electrifications - - -
>
>
> vy 73 de Wolfgang, DC2FR @ DB0GV, JO40FD, Frankfurt - Germany.
>
[ Received via HF CLOVER at KB6LE ]
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