Searching \ for 'AC Power Generation' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/power.htm?key=power
Search entire site for: 'AC Power Generation'.

Truncated match.
PICList Thread
'AC Power Generation'
1998\07\25@035134 by John Fimognari

picon face
To the PIC list,
Sorry Fellas to bore you,

But the power supply problem in the good old US of A interests me. I did
not know that you guys had a such backward power distribution system.
Down under in Aus we use a more civilised system. The power is generated
by delta (triangular) wound alternators. 3 phase is distributed to the
final point where the transformer is delta wound high tension primary
and star ( Y ) wound low tension secondary. 415 volts across Phases and
240 volts to the centre tap. This is the neutral wire which is also
earthed. (grounded for the USA people). The four wire system is the
retriculation system used for commercial and domestic consumption.

We use a system called Main Earth - Neutral (MEN). The neutral and earth
conductors are joined together behind the main switchboard panel and a
main earth wire is run to the copper water supply and bonded to an
earthing electrode. In essence every property is also an earthing
electrode station.

Standards Association Australia states that the neutral potential is to
be within 5% of the earth potential. ie 12 volts for 240 volts. In
effect the earth wire is used only as a safety wire. The only time
current flows through this wire is in a fault condition. It is there to
save lives.

No wonder you guys in the USA are having problems with your PICS and
RFI. With a floating neutral system and doddgy earthing system how do
you get rid of the nasties in your main power supply?

Our 240 volt, 10 amp 3 pin plugs use the same size pins,and yes we have
the live pin burn out problem as well.

Regards,
John Fimognari
Perth,
Western Australia.

1998\07\25@051012 by Eric Smith

flavicon
face
John Fimognari <spam_OUTjohnfimoTakeThisOuTspamVIANET.NET.AU> writes:
> No wonder you guys in the USA are having problems with your PICS and
> RFI. With a floating neutral system and doddgy earthing system how do
> you get rid of the nasties in your main power supply?

What makes you think we use floating neutral?  I'm not familiar with the
precise details of our NEC (National Electrical Code), but I do know that
the neutral is required to be grounded at the main breaker panel of a
building.

1998\07\25@063934 by Morgan Olsson

picon face
I believe this system is the most used over the world.
No wonder since it has most advantages, in power generation, distribution,
and local consumption, both for small and large appliances.

Just to inform about european standard, the difference is that we now have
230VAC phase-earth, 400V between phases.  A few years ago there were some
countries on 220V phase-earth, some 240V phase-earth.

It«s obvious that different standardisation commitees found that a
three-phase system at about 230VAC phase-earth is optimum for power
systems, som we agreed to set the common standard to 230V, with deviation
allowed to include 220 and 240V elder spec.

For connectors we have the old shuko connector in most of europe (i believe):
It is *very* rigid, about 3,5 cm ( 1 3/8 inch) diameter with two equal
round pins fo rlive and neutral, and *two* safety earth on the sides
guaranteed to always make first - disconnect first - and theyre double.
(the horisontal lines on top and bottom of picture:
      _
   /     \
  ( o   o )
   \  _  /

For lighter applinces, unearthed, (wall plug transformer, desk lamp etc)
there is the compatible euro connector
    _____
  < o   o >

(I really miss a "overline" character here)

The plug is thinner but can be plugged into both shuko and euro outlets.
The euro outlets save space.  They are not as rigid as shuko, but much more
rigid than 110V USA toy-plugs.  (here we often use the latter for 24V AC...)

Both shuko and euro utlets are recessed to give extra mechanical support,
and also makes it virtually impossible to approach the connectings with any
metal stick even when the plug is half-way out.  (kid playing etc)

On top of that, the eouro pins usually are isolated to the half closest to
the connector body, and a few shuko is too.  

And there are outlets that closes the holes and only opens as the plug is
inserted.  ("child-proof")

I have also seen shukos wich also accepts a earth pin from the outlet so
they also support another very similar outlet (french? australian?)

For three-phase connectors there are those five pole round industrial
connectors standardized in 16A 25A 35A 63A etc.  They carry three phases,
neutral and protective earth.  (Of course the phase order is also
standardized so the motors always run in the right direction...)

For homes there are the low profile five pin connectors, used by example
for electric stoves.


* More about three phase advantage:

For stoves and other heaters the three phase is especially good as the
heating elements gan get 400V or 230V, depending on connected between
phases, or to neutral, on top of the possibility of connecting elements in
series.  Result is cheaper elements (less different windings)  and cheaper
contacts (less maximun current)

It is also used to make elctric heaters adjust power in fine steps.

To make the main fusing of a household small there are those sensing
heaters (etc) that can sense the load of the phases, and distribute load
and olnly load each phase up to a maximum rating.  So when a high load on
one phase go on (hair dryer, coffee boiler) the heater adjust to less load
on that phase.

For motors, as the troque is constant during the power cycle, the "hum" of
machinery is reduced, and most important, there are due to the continuous
magnetic field less losses.

The magnetic fields of a three phase power distrubution transformer is much
less than from an equally large two-phase.  The same for three phase versus
two phase motors.

...

We have had both DC and lower voltage AC, in local nets before (and for
very small local nets that migth have been optimal by that times
technology), but now almost whole europe, australia, at least parts of
asia, africa etc, use three-phase 400V-phase-phase voltage.

We eagerly await north america to join us.


BTW speaking of voltage, in the nordic languages we have two different
words for voltage-between-two-arbitrary-points and
voltage-between-a-point-and-earth (which makes speaking of power nets and
other electric cirquits much more clear, and safe)


Regards
/Morgan

At 15:49 1998-07-25 +0800, you wrote:
{Quote hidden}

/  Morgan Olsson, MORGANS REGLERTEKNIK, SE-277 35 KIVIK, Sweden \
\  .....mrtKILLspamspam@spam@iname.com, ph: +46 (0)414 70741; fax +46 (0)414 70331    /

1998\07\25@110328 by paulb

flavicon
face
Morgan Olsson wrote:

> The plug is thinner but can be plugged into both shuko and euro
> outlets.  The euro outlets save space.

 But the "Euro" plugs have no earth.

> I have also seen shukos wich also accepts a earth pin from the outlet
> so they also support another very similar outlet (french? australian?)

 I gather that projecting earth pin just misses the side of a "euro"
plug.  It also polarises a "Shuko" outlet in three-wire mode which it
seems does not otherwise happen, i.e., there are two lines, neither
active or neutral.

 Virtually *all* the Shuko plugs I see here, at least in recent years,
have the extra ground female.  They are certainly not *used* here,
though I have collected a number and keep my eye out for matching
sockets as a matter of interest.  There are a lot of them floating about
on IEC cords imported with appliances and subsequently trashed.  Similar
with US plugs.  I assumed the (extra ground female) variant was the
preferred option to which most areas were converting.

 Australia and NZ are *completely*      / \   Flat
standardised on the "sad" 3-pin plug:     |    pins

 Two "specials" for certain circuits are round earth, and both active
and neutral round.  High current plugs sport longer flat ground pins,
possibly a large round one.  I suspect the current-carrying pins are
slightly larrger, but sockets would be required to make firm contact
still with standard (10-amp) plugs.

 New rules specify a slightly sunken round recess in sockets, but
barely half the depth of the Shuko (quite similar diameter).  Of course,
all old model Plug-Packs (Wall-Warts to the Yanks) would fall out.  At
this moment, it's only on sale as a flange around (moulded) line sockets
on extensions.

> For three-phase connectors there are those five pole round industrial
> connectors standardized in 16A 25A 35A 63A etc.  They carry three
> phases, neutral and protective earth.

 It is likely ours are identical (some are only four-pin, no neutral).

> For homes there are the low profile five pin connectors, used by
> example for electric stoves.

 All fixed wiring in this country.

> To make the main fusing of a household small there are those sensing
> heaters (etc) that can sense the load of the phases, and distribute
> load and olnly load each phase up to a maximum rating.  So when a high
> load on one phase go on (hair dryer, coffee boiler) the heater adjust
> to less load on that phase.

 Wow!

> The magnetic fields of a three phase power distrubution transformer is
> much less than from an equally large two-phase.

 Unless the latter is double-wound, i.e., on both legs.

--
 Cheers,
       Paul B.

1998\07\25@120921 by paulb

flavicon
face
Morgan Olsson wrote:

> The plug is thinner but can be plugged into both shuko and euro
> outlets.  The euro outlets save space.

 But the "Euro" plugs have no earth.

> I have also seen shukos wich also accepts a earth pin from the outlet
> so they also support another very similar outlet (french? australian?)

 I gather that projecting earth pin just misses the side of a "euro"
plug.  It also polarises a "Shuko" outlet in three-wire mode which it
seems does not otherwise happen, i.e., there are two lines, neither
active or neutral.

 Virtually *all* the Shuko plugs I see here, at least in recent years,
have the extra ground female.  They are certainly not *used* here,
though I have collected a number and keep my eye out for matching
sockets as a matter of interest.  There are a lot of them floating about
on IEC cords imported with appliances and subsequently trashed.  Similar
with US plugs.  I assumed the (extra ground female) variant was the
preferred option to which most areas were converting.

 Australia and NZ are *completely*      / \   Flat
standardised on the "sad" 3-pin plug:     |    pins

 Two "specials" for certain circuits are round earth, and both active
and neutral round.  High current plugs sport longer flat ground pins,
possibly a large round one.  I suspect the current-carrying pins are
slightly larrger, but sockets would be required to make firm contact
still with standard (10-amp) plugs.

 New rules specify a slightly sunken round recess in sockets, but
barely half the depth of the Shuko (quite similar diameter).  Of course,
all old model Plug-Packs (Wall-Warts to the Yanks) would fall out.  At
this moment, it's only on sale as a flange around (moulded) line sockets
on extensions.

> For three-phase connectors there are those five pole round industrial
> connectors standardized in 16A 25A 35A 63A etc.  They carry three
> phases, neutral and protective earth.

 It is likely ours are identical (some are only four-pin, no neutral).

> For homes there are the low profile five pin connectors, used by
> example for electric stoves.

 All fixed wiring in this country.

> To make the main fusing of a household small there are those sensing
> heaters (etc) that can sense the load of the phases, and distribute
> load and olnly load each phase up to a maximum rating.  So when a high
> load on one phase go on (hair dryer, coffee boiler) the heater adjust
> to less load on that phase.

 Wow!

> The magnetic fields of a three phase power distrubution transformer is
> much less than from an equally large two-phase.

 Unless the latter is double-wound, i.e., on both legs.

--
 Cheers,
       Paul B.


Paul,
I have a feeling that Aus copied or imported the SAD plug design from
the USA in the 1930's. I have seen it in old USA catalogues listed as a
220volt special plug.
The shrouds around the extension cable sockets were introduced because
the thickheads in the building industry were always dropping the
extension leads into water.
The 15amp plug pins and sockets and rocker switches are made of
different material than the 10amp version. The larger earth pin is a
polarising pin to stop the thickheads plugging a 15 amp plug into a
standard 10 amp socket. Unfortunately some of these clowns let loose
with a file. You can imagine what happens when you draw 15 amps out of a
10 amp socket. The power cable has a rating of 15 amps on a wire fuse
and 20 amps on a circuit breaker or HRC cartridge fuse. Breakers are
there to protect the cable and not the appliance. Unfortunately clowns
are clowns worldwide.
You can take a donkey to water, but you can't make him drink.
Regards,
john Fimognari

1998\07\25@143824 by Peter L. Peres

picon face
On Sun, 26 Jul 1998, Paul B. Webster VK2BZC wrote:

> Morgan Olsson wrote:
>
> > The plug is thinner but can be plugged into both shuko and euro
> > outlets.  The euro outlets save space.
>
>   But the "Euro" plugs have no earth.

No, but they are ONLY legal for IP2 cased equipment, where you have no
place to connect earth to anyway (must have no exposed metal parts
whatsoever, except unconnected decoration etc).

> with US plugs.  I assumed the (extra ground female) variant was the
> preferred option to which most areas were converting.

No, but most *hospitals* do. I understand that you are into medical
equipment yourself ? The polarized Schuko is mandatory in hospitals and
other such places. It is used almost nowhere else (sometimes lab equipment
for metrology and such).

The insulation specs of the Schuko are such, that the polarisation of the
plug does not matter. It's a good system.

>   Australia and NZ are *completely*      / \   Flat
> standardised on the "sad" 3-pin plug:     |    pins

Must come from being Down Under. We have it smiling, see ;) :

L   0  (front view on prongs of power plug)
\   /
 |
 G

The 2 \/ prongs are at the exact same distance as Euro and Schuko but they
are not round (the holes in the mask that is). The receptacle recess
outline is round. This causes tourists to try hard to plug in various
equipment brought along ;) If one enlarges the bores on the \/ pins then a
normal Euro connector can be used, but this makes the insertion of Schuko
plugs also possible, and that's dangerous.  Normal 'thin' legged European
wall warts fit without mods. That would be the low current Euro connector
(<= 2 Amps). All 3 prongs are identical and protrude equal distances from
the plug.

Fault current breakers are mandatory everywhere in new buildings etc. Very
few people avoid them (and they are usually stupid imho - with this
climate 90% of the population touches electrical appliances while barefoot
on tiled floors daily...).

>   New rules specify a slightly sunken round recess in sockets, but
> barely half the depth of the Shuko (quite similar diameter).  Of course,
> all old model Plug-Packs (Wall-Warts to the Yanks) would fall out.  At
> this moment, it's only on sale as a flange around (moulded) line sockets
> on extensions.

This recess is a part of our sockets and only wall warts with offset
prongs work (looks like a wall wart with 1/2 Euro connector growing out of
it, complete with prongs). unfortunately the recess is not deep enough to
stop someone from inserting a Schuko partially by force. Newer receptacles
have protruding plastic 'ears' that should prevent this (they stop the
Schukos at the -u- protrusion where the protection contact is).

I will never understand how these things are decided upon. You should see
the 'old' style phone plugs here.

The Schuko system is the best for hot-plugging imho. It touches ground
earth 1st and separates it last, and the plug can be made to be very
robust.

Peter

PS: This is really way OT. I'm stopping now.

1998\07\25@150013 by Morgan Olsson

picon face
At 01:01 1998-07-26 +1000, Paul B wrote:
>Morgan Olsson wrote:
>
>> The plug is thinner but can be plugged into both shuko and euro
>> outlets.  The euro outlets save space.
>
>  But the "Euro" plugs have no earth.

Right.

>> I have also seen shukos wich also accepts a earth pin from the outlet
>> so they also support another very similar outlet (french? australian?)
>
>  I gather that projecting earth pin just misses the side of a "euro"
>plug.

I think so.

{Quote hidden}

Nice :)

Is there also a compatible live + neutral only   / \  ?

Is there a reliable standard for *which* one is the live?

Is it specified for the polarised Shuko?

For the "apparatus connector" IEC320 found on back of PC:s and other
electronic appiances, is it specified which one is neutral?

It would really be nice if also the 2 pin Neutral + Live connectors are
polarised, so the floor lamp, when we shut it of by the switch, it is
guaranteed to be no voltage when we change the bulb.  Now we have to move
the sofa to pull the plug if we are careful.  (I do it since I was changing
a bulb in a floor lanp, ant the lamp socket broke to pieces...)

{Quote hidden}

Hopefully. Are they red colour?
On theese the ground is larger than the other (for maximum safety)

>(some are only four-pin, no neutral).

Here too.  Blue.

There are also similar 3-pin. Also blue.

>> For homes there are the low profile five pin connectors, used by
>> example for electric stoves.
>
>  All fixed wiring in this country.
>
<snip>
/  Morgan Olsson, MORGANS REGLERTEKNIK, SE-277 35 KIVIK, Sweden \
\  mrtspamKILLspaminame.com, ph: +46 (0)414 70741; fax +46 (0)414 70331    /

1998\07\27@133654 by Tom Handley

picon face
  John, here in the USA, our neutral and ground (earth) are connected
at the breaker panel. This is connected to the incomming supply ground.

  - Tom

At 03:49 PM 7/25/98 +0800, John Fimognari wrote:
{Quote hidden}

1998\07\27@153648 by paulb

flavicon
face
John Fimognari wrote to PICLIST (and somehow got my address in the
"Reply-to" field!):

> I have a feeling that Aus copied or imported the SAD plug design from
> the USA in the 1930's. I have seen it in old USA catalogues listed as
> a 220volt special plug.

 Quite possibly.  We must have copied one of the better things then, as
they are completely standard here and have no obvious problems.

> The shrouds around the extension cable sockets were introduced because
> the thickheads in the building industry were always dropping the
> extension leads into water.

 I don't quite see the (pun!) connection?

> The 15amp plug pins and sockets and rocker switches are made of
> different material than the 10amp version.

 That might account for the pins being the same size.

 And from Morgan Olsson:

> Is there also a compatible live + neutral only   / \  ?

 Indeed.  Makes a nice compact plug for double-insulated appliances.
Note it is still polarised so the switch can be kept in the "live" side.

> Is there a reliable standard for *which* one is the live?

 Yes (nowadays!).  Earth, Neutral, Active (Convention; clockwise
looking at the plug pins).

> Is it specified for the polarised Shuko?

 Hey, I'm not the expert here!  It would appear to be.

> For the "apparatus connector" IEC320 found on back of PC:s and other
> electronic appiances, is it specified which one is neutral?

 Definitely; it's embossed on the separate connectors.  It happens to
be the reverse of the above sequence.

> It would really be nice if also the 2 pin Neutral + Live connectors
> are polarised, so the floor lamp, when we shut it of by the switch, it
> is guaranteed to be no voltage when we change the bulb.  Now we have
> to move the sofa to pull the plug if we are careful.  (I do it since I
> was changing a bulb in a floor lanp, and the lamp socket broke to
> pieces...)

 I won't comment.  We have predominantly bayonet cap lamp fittings in
domestic use.

 Oh, let me explain something about our "sad" plugs.  The earth pin is
slightly longer so it contacts first and separates last as indeed it
does in most standards.  Having the earth on the bottom further means
that downward pull on the cord tends to seperate the "power" pins first.
The tangential alignment of the "power" pins means that they are further
separated from the skirt of the plug than they would be if radial and
thus more difficult to touch by accident.  This is equally true of the
two-pin American fittings.
--
 Cheers,
       Paul B.

More... (looser matching)
- Last day of these posts
- In 1998 , 1999 only
- Today
- New search...