In alt.engineering.electrical Michael Kennedy wrote:
|
| wrote in message
| ...
| In alt.engineering.electrical operator jay wrote:
| |
| | "You" wrote in message
| | ...
| | In article ,
| |
| | wrote:
| |
| | There are two different flavors of 220/230/240 volts. Some places
| | have a
| | simple system with one wire hot and one wire grounded. Other
| | places have
| | a split system where the voltage is split in half to get
| | 110/115/120 volts
| | relative to ground, by adding a additional "middle" conductor that
| | is the
| | grounded one.
| |
| | Sonny, you need to LEARN the difference between Ground and
| | Neutral......
| | before you spout any further BS.......
| |
| | What he wrote looks reasonable to me in terms of ground and neutral.
| | Neutral is the grounded conductor where I live. He does not say to
| | use a ground as a neutral, if that's what you're getting at. I can
| | only guess that that may be what you're getting at, you haven't really
| | said.
|
| He might be one of those "knows just enough to be really dangerous" people
| on the net. I didn't even mention "neutral". My intent was to explain it
| in a simpler way for someone to just understand the basic difference. The
| term "middle" was to convey a little more information than "neutral" would
| SNIP
|
| Well, I understood what he meant, but maybe I took it the wrong way. When he
| said middle conudctor I was thinking the center lug on the transformer which
| is grounded and used as the neutral.

That is what I meant when I said middle conductor. I intentionally avoided
calling it neutral for the person I was responding to. I did quote it to
make it clear (but this apparently was not clear enough for at least one
person) for others that I was using some other term.

--
|WARNING: Due to extreme spam, I no longer see any articles originating from |
| Google Groups. If you want your postings to be seen by more readers |
| you will need to find a different place to post on Usenet. |
| Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) |

Ï Ýãñáøå óôï ìÞíõìá
...
In alt.engineering.electrical Michael Kennedy
wrote:
|
| wrote in message
| ...
| In alt.engineering.electrical operator jay wrote:
| |
| | "You" wrote in message
| | ...
| | In article ,
| |
| | wrote:
| |
| | There are two different flavors of 220/230/240 volts. Some places
| | have a
| | simple system with one wire hot and one wire grounded. Other
| | places have
| | a split system where the voltage is split in half to get
| | 110/115/120 volts
| | relative to ground, by adding a additional "middle" conductor that
| | is the
| | grounded one.
| |
| | Sonny, you need to LEARN the difference between Ground and
| | Neutral......
| | before you spout any further BS.......
| |
| | What he wrote looks reasonable to me in terms of ground and neutral.
| | Neutral is the grounded conductor where I live. He does not say to
| | use a ground as a neutral, if that's what you're getting at. I can
| | only guess that that may be what you're getting at, you haven't
really
| | said.
|
| He might be one of those "knows just enough to be really dangerous"
people
| on the net. I didn't even mention "neutral". My intent was to explain
it
| in a simpler way for someone to just understand the basic difference.
The
| term "middle" was to convey a little more information than "neutral"
would
| SNIP
|
| Well, I understood what he meant, but maybe I took it the wrong way.
When he
| said middle conudctor I was thinking the center lug on the transformer
which
| is grounded and used as the neutral.

That is what I meant when I said middle conductor. I intentionally
avoided
calling it neutral for the person I was responding to. I did quote it to
make it clear (but this apparently was not clear enough for at least one
person) for others that I was using some other term.

--
Nope. LV (low voltage)230-V in Europe is just sufficient for 1 km distance.
MV (medium voltage) 20 kV for 60 km. HV (high voltage) 150 kV for 220 km.
EHV 400kV for 500 km with stability issues. 110 volt is so low you need a
transformer outside each building....



--
Tzortzakakis Dimitrios
major in electrical engineering
mechanized infantry reservist
hordad AT otenet DOT gr

--
Nope. LV (low voltage)230-V in Europe is just sufficient for 1 km
distance. MV (medium voltage) 20 kV for 60 km. HV (high voltage) 150 kV
for 220 km. EHV 400kV for 500 km with stability issues. 110 volt is so low
you need a transformer outside each building....



--
Tzortzakakis Dimitrios
major in electrical engineering
mechanized infantry reservist
hordad AT otenet DOT gr



Learn the system before you criticize it.

It's not 110V, it's 240V, we simply split it with a grounded center tap
which gives 120V between each side and neutral, or 240V between the sides..
There's no transformer per house, except rural applications. Generally 5-10
houses are on each transformer, sometimes more. The problem with long runs
is that the voltage fluctuates substantially with large loads such as
central air conditioning. Standard North American residential service is 200
Amps 240V, I gather this is quite a bit larger than typical European
domestic stuff, so stretching it over 1km distance would require
prohibitively large cables or suffer from wide voltage swings. Makes more
sense to run 7200V down the street and locate a smallish transformer near
every half dozen houses.

Ï "James Sweet" Ýãñáøå óôï ìÞíõìá
news:WMGTj.5083$ch1.2983@trndny09...


--
Nope. LV (low voltage)230-V in Europe is just sufficient for 1 km
distance. MV (medium voltage) 20 kV for 60 km. HV (high voltage) 150 kV
for 220 km. EHV 400kV for 500 km with stability issues. 110 volt is so
low you need a transformer outside each building....



--
Tzortzakakis Dimitrios
major in electrical engineering
mechanized infantry reservist
hordad AT otenet DOT gr



Learn the system before you criticize it.

It's not 110V, it's 240V, we simply split it with a grounded center tap
which gives 120V between each side and neutral, or 240V between the sides.
I'm perfectly aware of this, only in theory, though, as I've never been in
USA. I have worked, though in the decommisioned US base in Gournes, really
impressive your distribution systems:-)
And in Europe we have 400 V (3 phase) line to line voltage. It's 230 line to
earth. Large motors and conditioners use 3 phase. Normal residence is 40 A
230 V single phase, or for energy hogs 400 V 3 X 40 A 3 phase..
There's no transformer per house, except rural applications. Generally
5-10 houses are on each transformer, sometimes more. The problem with long
runs is that the voltage fluctuates substantially with large loads such as
central air conditioning. Standard North American residential service is
200 Amps 240V, I gather this is quite a bit larger than typical European
domestic stuff, so stretching it over 1km distance would require
prohibitively large cables or suffer from wide voltage swings. Makes more
sense to run 7200V down the street and locate a smallish transformer near
every half dozen houses.

Residential power in Sweden is 400V 3 phase, main fuses normally 25A
or lower.

Room outlets are wired with one phase, neutral and ground to get 230V.

There is a smallish transformer station in the neighborhood which
probably powers two entire blocks. I would guess somewhere around 20-30
houses.

? "Thomas Tornblom" ?????? ??? ??????
...
Residential power in Sweden is 400V 3 phase, main fuses normally 25A
or lower.

Room outlets are wired with one phase, neutral and ground to get 230V.

There is a smallish transformer station in the neighborhood which
probably powers two entire blocks. I would guess somewhere around 20-30
houses.
Absolutely the same here, in Greece we are using only Schuko sockets, from
german Schutzkontakt, security contact. There is a larger substation, maybe
2-3 for a city (in Iraklion we have 3, 180,000 residents) that steps down
from the transmission voltage, 150 kV down to primary distribution voltage,
15 kV that is the distributed with cables buried in earth. Our local power
station has units with 15 kV (older) and newer with 6.6 kV alternators, all
is stepped up to 150 kV even for the ~15 km to Iraklion. In capitals, like
Athens, electricity comes at 400 kV, is stepped down to 150 kV for secondary
transmission, again goes to the areas af the city with underground cables,
stepped down to 15 kV locally, and then distributed again (the main
generation facilities are in Kozani, West Macedonia, and they burn brown
coal. Typical size of a unit is 300 MW, voltage 21 kV and current 10 kA
which is stepped up to 400 kV, 400 A line current for transmission to Athens
and Thessaloniki).



--
Tzortzakakis Dimitrios
major in electrical engineering
mechanized infantry reservist
hordad AT otenet DOT gr

In article ,
Thomas Tornblom writes:
Residential power in Sweden is 400V 3 phase, main fuses normally 25A
or lower.

Room outlets are wired with one phase, neutral and ground to get 230V.

There is a smallish transformer station in the neighborhood which
probably powers two entire blocks. I would guess somewhere around 20-30
houses.

Similar in UK.

In most European countries, there's a single phase current limit,
above which you have to take a 3-phase supply. In the UK, that's
100A, so it's not very common to have a 3-phase supply although
you can ask for one if you want a 3-phase supply. In some other
European countries, the single phase limit is as low as 20A, so
just about everyone has a 3-phase supply.

Residential substation transformers (11kV down to 230/400) are
usually 1MVA, feeding a number of streets. A substation may have
more than one transformer in some cases (although they usually
only start out with one). Obviously, smaller transformers are
used where there aren't so many houses, and these are sometimes
pole mounted if the wiring is overhead.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In article ,
Andrew Gabriel wrote:
In article ,
Thomas Tornblom writes:
Residential power in Sweden is 400V 3 phase, main fuses normally 25A
or lower.

Room outlets are wired with one phase, neutral and ground to get 230V.

There is a smallish transformer station in the neighborhood which
probably powers two entire blocks. I would guess somewhere around 20-30
houses.

Similar in UK.

In most European countries, there's a single phase current limit,
above which you have to take a 3-phase supply. In the UK, that's
100A, so it's not very common to have a 3-phase supply although
you can ask for one if you want a 3-phase supply. In some other
European countries, the single phase limit is as low as 20A, so
just about everyone has a 3-phase supply.

Residential substation transformers (11kV down to 230/400) are
usually 1MVA, feeding a number of streets. A substation may have
more than one transformer in some cases (although they usually
only start out with one). Obviously, smaller transformers are
used where there aren't so many houses, and these are sometimes
pole mounted if the wiring is overhead.

or, as in the case of the transformer that feeds my house, pole mounted in
field with the output cables going underground immediately.

--
From KT24 - in "Leafy Surrey"

Using a RISC OS computer running v5.11

In article WMGTj.5083$ch1.2983@trndny09,
"James Sweet" writes:

It's not 110V, it's 240V, we simply split it with a grounded center tap
which gives 120V between each side and neutral, or 240V between the sides..

It's the regulation at 120V which people notice.
If you want to call it a 240V supply, then you
need to call EU supplies 400V or 415V. That's
equally misleading.

There's no transformer per house, except rural applications. Generally 5-10
houses are on each transformer, sometimes more. The problem with long runs
is that the voltage fluctuates substantially with large loads such as
central air conditioning. Standard North American residential service is 200
Amps 240V, I gather this is quite a bit larger than typical European
domestic stuff, so stretching it over 1km distance would require
prohibitively large cables or suffer from wide voltage swings. Makes more
sense to run 7200V down the street and locate a smallish transformer near
every half dozen houses.

The transformers are small in comparison, which gives poor
regulation in comparison (and as I said before, it's the
regulation at 120V which is the primary concern -- regulation
of 240V across 2 hots doesn't matter much for typical US 240V
loads).

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

The transformers are small in comparison, which gives poor
regulation in comparison (and as I said before, it's the
regulation at 120V which is the primary concern -- regulation
of 240V across 2 hots doesn't matter much for typical US 240V
loads).



Regardless, the regulation is very good. I monitored mine for a while
and never saw it dip below 118V or go above 122V, most of the time it
was just about spot on 120V. A friend in the UK was doing the same on
his and it went as low as 224V and as high as 246V. We've done a lot of
comparing and have agreed that neither system is inherently better or
worse than the other, both have advantages and disadvantages.

In alt.engineering.electrical Andrew Gabriel wrote:
| In article WMGTj.5083$ch1.2983@trndny09,
| "James Sweet" writes:
|
| It's not 110V, it's 240V, we simply split it with a grounded center tap
| which gives 120V between each side and neutral, or 240V between the sides..
|
| It's the regulation at 120V which people notice.
| If you want to call it a 240V supply, then you
| need to call EU supplies 400V or 415V. That's
| equally misleading.

The effect of loading and how it affects voltage depends on how well balanced
the TWO 120 volts phases are. If they are in balance, then the effect of the
loading on the voltage works as if you were considering the voltage at 240 volts.

If you get a three phase supply, and keep it balanced with the single phase
line to neutral loads, then the voltage regulation is going to be just like you
had loaded it with line-to-line loads, 208 volts in North America and 400 volts
in Europe.

If your neighborhood transformer is three phase, even if your home gets only
one phase of it (at just 230 volts), you still get advantage because other
homes will be distributed over other phases to keep it in balance.

But if you are comparing a single phase system, North American 120/240 with
three wires, vs. European 230 with two wires, it works out to be about the
same. The difference is we pay more for the extra wire, but we have a lower
line to ground shock risk (which isn't really much of an issue anymore with
improvements in safety in various ways such as GFI/RCD protection, better
rules on installations, etc).

So if you moved from Europe where you had 400/230 volts three phase in your
home, and came to North American and discovered we really had 480/277 volts
three phase, would that trouble you (assuming all appliances were designed
for that)?

--
|WARNING: Due to extreme spam, I no longer see any articles originating from |
| Google Groups. If you want your postings to be seen by more readers |
| you will need to find a different place to post on Usenet. |
| Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) |

? "Andrew Gabriel" ?????? ??? ??????
...
In article WMGTj.5083$ch1.2983@trndny09,
"James Sweet" writes:

It's not 110V, it's 240V, we simply split it with a grounded center tap
which gives 120V between each side and neutral, or 240V between the
sides..

It's the regulation at 120V which people notice.
If you want to call it a 240V supply, then you
need to call EU supplies 400V or 415V. That's
equally misleading.

There's no transformer per house, except rural applications. Generally
5-10
houses are on each transformer, sometimes more. The problem with long
runs
is that the voltage fluctuates substantially with large loads such as
central air conditioning. Standard North American residential service is
200
Amps 240V, I gather this is quite a bit larger than typical European
domestic stuff, so stretching it over 1km distance would require
prohibitively large cables or suffer from wide voltage swings. Makes more
sense to run 7200V down the street and locate a smallish transformer near
every half dozen houses.

The transformers are small in comparison, which gives poor
regulation in comparison (and as I said before, it's the
regulation at 120V which is the primary concern -- regulation
of 240V across 2 hots doesn't matter much for typical US 240V
loads).
The regulation, at least in Europe, is done at 150/15 kV substations and at
the HV side of the transformers, thus at 150 kV. Typical current for 2 x 25
MVA transformers is 150 A, 150 kV and of course secondary at 15 kV, 1500 A.
The regulation is done automatically with tap changers, live. The local
transformers at your neighborhood are fixed tap, 15 kV (they intend to
change everything to 20 kV).



--
Tzortzakakis Dimitrios
major in electrical engineering
mechanized infantry reservist
hordad AT otenet DOT gr

In article ,
"Tzortzakakis Dimitrios" writes:

? "Andrew Gabriel" ?????? ??? ??????
...
In article WMGTj.5083$ch1.2983@trndny09,
"James Sweet" writes:

It's not 110V, it's 240V, we simply split it with a grounded center tap
which gives 120V between each side and neutral, or 240V between the
sides..

It's the regulation at 120V which people notice.
If you want to call it a 240V supply, then you
need to call EU supplies 400V or 415V. That's
equally misleading.

There's no transformer per house, except rural applications. Generally
5-10
houses are on each transformer, sometimes more. The problem with long
runs
is that the voltage fluctuates substantially with large loads such as
central air conditioning. Standard North American residential service is
200
Amps 240V, I gather this is quite a bit larger than typical European
domestic stuff, so stretching it over 1km distance would require
prohibitively large cables or suffer from wide voltage swings. Makes more
sense to run 7200V down the street and locate a smallish transformer near
every half dozen houses.

The transformers are small in comparison, which gives poor
regulation in comparison (and as I said before, it's the
regulation at 120V which is the primary concern -- regulation
of 240V across 2 hots doesn't matter much for typical US 240V
loads).
The regulation, at least in Europe, is done at 150/15 kV substations and at
the HV side of the transformers, thus at 150 kV. Typical current for 2 x 25
MVA transformers is 150 A, 150 kV and of course secondary at 15 kV, 1500 A.
The regulation is done automatically with tap changers, live. The local
transformers at your neighborhood are fixed tap, 15 kV (they intend to
change everything to 20 kV).

I'm referring to the transformer regulation (and also the LV
supply cable voltage drop) response to load changes. E.g. if
I switch on my 10kW shower, that's a 0.1% change against the
max load of my 1MVA substation transformer and therefore
makes no perceivable difference to the voltage in my house.
If I were to try that on a US 50kVA transformer, that load
is going to trigger a change of 20% of the transformer
regulation, which is much more significant and would
certainly be visible as a brightness change in light bulbs.

Having lived in both countries, I would say it's pretty much
expected in the US that lights dim even with quite moderate
loads coming on, whereas it's rare in the UK (generally only
in rural areas with long supply lines). There are many
contributory factors to this difference, but the 120V verses
240V (or if you must, 240V verses 415V) is ultimately the
underpinning reason.

Automatic tap changing in the HV network is completely
invisible to the residential consumer, as indeed it should
be.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

In alt.engineering.electrical Andrew Gabriel wrote:

| I'm referring to the transformer regulation (and also the LV
| supply cable voltage drop) response to load changes. E.g. if
| I switch on my 10kW shower, that's a 0.1% change against the
| max load of my 1MVA substation transformer and therefore
| makes no perceivable difference to the voltage in my house.
| If I were to try that on a US 50kVA transformer, that load
| is going to trigger a change of 20% of the transformer
| regulation, which is much more significant and would
| certainly be visible as a brightness change in light bulbs.

What is the available fault current in these situations?

--
|WARNING: Due to extreme spam, googlegroups.com is blocked. Due to ignorance |
| by the abuse department, bellsouth.net is blocked. If you post to |
| Usenet from these places, find another Usenet provider ASAP. |
| Phil Howard KA9WGN (email for humans: first name in lower case at ipal.net) |

Andrew Gabriel wrote:

In article ,
"Tzortzakakis Dimitrios" writes:

? "Andrew Gabriel" ?????? ??? ??????
...
In article WMGTj.5083$ch1.2983@trndny09,
"James Sweet" writes:

It's not 110V, it's 240V, we simply split it with a grounded center tap
which gives 120V between each side and neutral, or 240V between the
sides..

It's the regulation at 120V which people notice.
If you want to call it a 240V supply, then you
need to call EU supplies 400V or 415V. That's
equally misleading.

There's no transformer per house, except rural applications. Generally
5-10
houses are on each transformer, sometimes more. The problem with long
runs
is that the voltage fluctuates substantially with large loads such as
central air conditioning. Standard North American residential service is
200
Amps 240V, I gather this is quite a bit larger than typical European
domestic stuff, so stretching it over 1km distance would require
prohibitively large cables or suffer from wide voltage swings. Makes more
sense to run 7200V down the street and locate a smallish transformer near
every half dozen houses.

The transformers are small in comparison, which gives poor
regulation in comparison (and as I said before, it's the
regulation at 120V which is the primary concern -- regulation
of 240V across 2 hots doesn't matter much for typical US 240V
loads).
The regulation, at least in Europe, is done at 150/15 kV substations and at
the HV side of the transformers, thus at 150 kV. Typical current for 2 x 25
MVA transformers is 150 A, 150 kV and of course secondary at 15 kV, 1500 A.
The regulation is done automatically with tap changers, live. The local
transformers at your neighborhood are fixed tap, 15 kV (they intend to
change everything to 20 kV).

I'm referring to the transformer regulation (and also the LV
supply cable voltage drop) response to load changes. E.g. if
I switch on my 10kW shower, that's a 0.1% change against the
max load of my 1MVA substation transformer and therefore
makes no perceivable difference to the voltage in my house.
If I were to try that on a US 50kVA transformer, that load
is going to trigger a change of 20% of the transformer
regulation, which is much more significant and would
certainly be visible as a brightness change in light bulbs.

Having lived in both countries, I would say it's pretty much
expected in the US that lights dim even with quite moderate
loads coming on, whereas it's rare in the UK (generally only
in rural areas with long supply lines). There are many
contributory factors to this difference, but the 120V verses
240V (or if you must, 240V verses 415V) is ultimately the
underpinning reason.


The central air kicks on without my lights dimming, and I am in North
Central Florica.


Automatic tap changing in the HV network is completely
invisible to the residential consumer, as indeed it should
be.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]


--
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Tzortzakakis Dimitrios wrote:

The regulation, at least in Europe, is done at 150/15 kV substations and at
the HV side of the transformers, thus at 150 kV. Typical current for 2 x 25
MVA transformers is 150 A, 150 kV and of course secondary at 15 kV, 1500 A.
The regulation is done automatically with tap changers, live. The local
transformers at your neighborhood are fixed tap, 15 kV (they intend to
change everything to 20 kV).


So they have developed 100% efficient transformers?


--
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Use any search engine other than Google till they stop polluting USENET
with porn and junk commercial SPAM

If you have broadband, your ISP may have a NNTP news server included in
your account: http://www.usenettools.net/ISP.htm

In article ,
"Michael A. Terrell" wrote:

So they have developed 100% efficient transformers?

Yep, their called Super Conducting Transformers, and they have been
around the LABS, for about 15 years now. Only one BIG problem with them.
They only work at 20 Degrees Kevin or lower in temperature.

? "Michael A. Terrell" ?????? ??? ??????
m...

Tzortzakakis Dimitrios wrote:

The regulation, at least in Europe, is done at 150/15 kV substations and
at
the HV side of the transformers, thus at 150 kV. Typical current for 2 x
25
MVA transformers is 150 A, 150 kV and of course secondary at 15 kV, 1500
A.
The regulation is done automatically with tap changers, live. The local
transformers at your neighborhood are fixed tap, 15 kV (they intend to
change everything to 20 kV).


So they have developed 100% efficient transformers?

.net/ISP.htm
Of course not:-) These are approximate figures (like the 21 kV 10 kA
alternator, which in fact is 9823 A 21200 volts or whatever). But the
efficiency of large transformers or transmission lines, when they operate at
optimum is 99%.




--
Tzortzakakis Dimitrios
major in electrical engineering
mechanized infantry reservist
hordad AT otenet DOT gr