Bruce in Bangkok writes:

All distribution transformers, sometimes called "pole pigs", that I
have seen had some sort of voltage adjusting system, usually referred
to as taps. Usually they are an actual bolted "tap" and you open the
transformer and set the output voltage by making the proper tap
connection when the transformer is installed and frankly it is usually
ignored thereafter.

What I was talking about appear to be used to adjust for supplied voltage
(they're often used right after a stepdown transformer bank) or long
runs, which may produce somewhat variable voltages that need adjustment
at times.

The other "cans" you often see on poles are capacitors used to adjust
the power factor on some secondaries.

Around here, capacitors for power factor compensation are rectangular
boxes with two bushings on top, on poles, in banks of 3, 6 or sometimes 9.

Like the ones Phil mentioned, the cans I talked about hum.

writes:

The really strange thing is Brazil has 220 volts all around the country,
with 60 Hz in some parts and 50 Hz in others, and used to use the American
120 volt 2-blade outlet/plug with 220 volts (you can be in for a surprise
with that).

The Philippines uses 220V 60Hz with US-style 2 blade outlets as well.

In alt.engineering.electrical Tzortzakakis Dimitrios wrote:

| ? ?????? ??? ??????
| ...
| In alt.engineering.electrical Tzortzakakis Dimitrios
| wrote:
|
| | Professional washing machines. One of my very first days 'in the field'
| was
| | to connect some of them. They have a large heating element, you can
| connect
| | it single phase, or 3 phase, it just heats up faster (of course) when
| you
| | connect it 3 phase. (they have a single phase motor, so it works also in
| | pure 230 V).
|
| If it has 3 elements rated for 230 volts, with 3 separate connections that
| would be to three separate phase for a three phase feed, and all connected
| to the one phase for a single phase feed, then it should heat up at the
| same
| speed, while drawing three times the current (not accounting for the
| motor).
|
| I don't know why it should heat up faster in three phase, or why you would
| say "of course" about it. I would think it would heat up faster if you
| took
| it over to London and hooked it up to a 240 volt supply.
|
| Maybe you connected with single phase just one element? The rest two
| remained unconnected? (3 230 volts elements, connected wye). I'm sure it
| heated up faster, in 3 phase connection.

You were the one who said "it just heats up faster (of course) when you
connect it 3 phase."

I would disagree.

But the fact that you said "(of course)" seems you presume that to be the
general case. Now your most recent comment at least acknowledges that if
not all elements are connected, it won't heat up as fast.

In the simple case, each of 3 elements is individually wired, so you have
a total of 6 leads. When connecting to three phase, one lead of each is
connected to neutral, and each of the other leads is connected to separate
phases. When connecting to single phase, they are all wired in parallel.
Both cases always involve one of the leads from each element connected to
neutral, so those 3 leads can be pre-connected together. So you could have
just 4 leads. The common neutral lead needs to be rated for all the current
together for it to be rated properly for single phase.

It should apply the same voltage (230V) to each element, and they should each
draw the same current. How would you believe this would be slower to heat?

If the 3 elements were wired _internally_ in star without a neutral lead,
it would still work fine on three phase as long as all elements were equal
impedance. But on single phase, you could only activate 2 of the elements,
and that would be 2 in series fed with 230 volts. You'd only get 1/6 the
power that way.

Are you assuming the elements would be wired that way? That would clearly
NOT be intended for single phase connection.

The 3 elements could be wired _internally_ in delta. In this case, these
would have to be 400V elements. Connecting 2 leads to 230 volts would still
give you only 1/6 the power (but more evenly distributed in this case).

So what is the situation that makes _you_ believe that 3 elements connected
to single phase _will_ draw less power to heat the water than when connected
to three phase?

--
|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) |

wrote in message
...
In alt.engineering.electrical Don Kelly wrote:

| If I read you correctly, you want to use a second secondary (lower power
| rating) which is tapped and put in series with the main secondary. Now
once
| you do this, you have in effect a single secondary with taps just as in
a
| conventional tapped secondary. Sure the "tapped section" is lower power-
| because it is a lower voltage but it still has to handle the same
current.
| Nothing is gained.
| The problem in tap changing is not "power" but the current being
switched.

No, that is not what I tried to explain. I'll try again:

The main transformer would have 2 secondaries. These 2 secondaries are
NOT
wired in series with each other. The smaller of these secondaries will
have
taps. The tapped smaller secondary feeds another smaller transformer.
The
larger secondary of the main transformer, and the only secondary of the
smaller
auxiliary transformer, would be wired in series. So the taps are only
dealing
with the current of the lower power "tapping section". The smaller
secondary
of the main transformer, and the primary of the auxiliary transformer, can
be
wired for whatever voltage/current works out best.


| In either case the voltage driving short circuit current on tap changing
is
| that between taps
| Delta V =A(delta n) Delta Z =B(delta n)^2. where delta n is the change
in
| turns between taps. The short circuit current on such a change will be
| proportional to 1/(delta n).
|
| If you want fine control, then you could go to sliding carbon brush as
in a
| variac. The first idea of a separate transformer feeding a variac will
not
| solve the "too low" voltage problem of the variac because you are still
| dealing with an autotransformer.

In that first scheme, adjusting the variac to the lowest voltage would be
reducing the voltage contributed by the boost transformer. There is still
the original supply voltage going around the variac, "plus" (actually
minus)
the buck voltage (to select the range I want). Since the variac is an
autotransformer itself, it merely feeds the primary of the boost
transformer.
Note that in this case the "boost" transformer is wired as an isolation
transformer. I should have mentioned that. If needed, I guess I could
draw
some ASCII diagrams or try to get something made graphically (all the
tools
I have to do that suck, except for Visio which needs Windows to run and I
don't have a spare machine to do that at the moment).
---------------------------------
Actually I see added complexity without any gain. You may be doing the tap
changing at a lower current and higher voltage but there will be no "lower
Power" switching but there will be more losses during operation even when
not changing taps. I suspect the complexity and the losses together would
cost more than a conventional tap changer. There are some circuit factors
involved which may be undesirable but I haven't done a proper analysis.
--

Don Kelly
remove the X to answer
----------------------------

----------------------------
wrote in message
...
In alt.engineering.electrical Don Kelly wrote:

| Just a bitch that we have dealt with befo
|
| Phil- please realize that 207.846096....... is meaningless except that
it is
| "about 208". 208V is correct to 3 significant figures which is actually
| better than one can assume to be true in practice. If the voltage line
to
| neutral is actually 120.V (note the decimal) then we have 3 significant
| digits implying something between 119.5 Vand 120.5.V
| Then all you can truly claim is 208.V
| If it is 120.0V then there is reason to assume 208.0 V but no more
decimals
| than that.
| If you have a meter which gives you 120.000000V with less than 1 part in
120
| million error then you can claim 207.846097V for line to line voltage
Do
| you have such a meter?
|
| Engineering and physics students who ignore the principle of
"significant
| digits" lose marks for this "decimal inflation".
|
| Sure- you can let the calculator carry the extra digits (as it will do
| internally) but accepting these as gospel truth to the limit of the
| calculator or computer display is simply not on as you can't get better
| accuracy from a calculation than the accuracy of the original data
(actually
| you will lose a bit). All that you get rid of is round off errors in
| calculations.
|
| Since, as you say, precise voltage is not really practical, then
| multi-decimal point numbers are meaningless. If we say 120V +/-10% then
we
| are talking about 108-132V which for line to line becomes 187-229V
(average
| 208V) and any extra decimal points don't mean anything.

You didn't notice the :-) I put on the number?

We've been over this. I know the practice of significant digits, and how
the voltages are designated (two different reasons you can get 208). I do
follow the practice of carrying exactly the result of calculations into
other calculations. I also use over significance in comparison of
numbers.

But I also know that rounding is a form of noise. So I avoid it until the
time I end up with the final result. So if I multiply 120 by the square
root of three I do get a number like 207.84609690826527522329356 which is
either carried as-is into the next calculation, or rounded if it is the
final answer. If some other strange calculation happens to give me the
value 207.84609690826527522329356 then I know it is effectively equivalent
to 120 times the square root of three in some way. But if what I get is
208.455732193971783228 then I know it has nothing to do with 120 times the
square root of three, even though it, too, would end up as 208 if rounded
to 3 significant digits.

When it comes to _measured_ amounts, as opposed to synthetic ones, then
the
significance rules dictate how to round the results. With synthetic
numbers
(e.g. numbers I can just pick), I can also pick the rounding rules for the
final results. But if I don't know that the calculations are done (e.g. I
am not merely giving a designation for a voltage system), where someone
else
may take those numbers and do more calculations and round the results,
then
I do use more significance. But that is no different to me than just
carrying
that number from one calculation stage to another.

--
|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) |
-------------------------
Fair enough- but still overkill. For the bulk of the calculations that one
does, single precision is more than adequate. Anything more, even for
comparison of numbers is really fluff.
I simply set my display to show the desired sig figs and let the calculator
deal with the rest in its normal internal mode. I don't want to see the
extra digits, or , if I do, 1 or 2 is sufficient. Ditto with the computer.
Only if I am dealing with ill conditioned sets of simultaneous equations ,
will I really require double precision.
--

Don Kelly
remove the X to answer

NameNotImportant wrote in
m:

lbm?

I'm not sure on your units.

pounds (mass), lbm, as opposed to pounds (force), lbf, or lb.

It is necessary to distinguish between mass and force but they are both
measured in pounds in the english system.

Metric is 'much simpler' with grams(mass) and newtons(force).





--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

remove ch100-5 to avoid spam trap

In article 39,
says...
NameNotImportant wrote in
m:

lbm?

I'm not sure on your units.

pounds (mass), lbm, as opposed to pounds (force), lbf, or lb.

It is necessary to distinguish between mass and force but they are both
measured in pounds in the english system.

The "English" system uses the "stone" as the measurement of mass.
The pound ('lb') is the unit of *FORCE*.

Metric is 'much simpler' with grams(mass) and newtons(force).

Evidently *you* think the "English" system is too complicated. ;-)

--
Keith

krw wrote in news:MPG.2297621d47f3215f989c18
@news.individual.net:

In article 39,
says...
NameNotImportant wrote in
m:

lbm?

I'm not sure on your units.

pounds (mass), lbm, as opposed to pounds (force), lbf, or lb.

It is necessary to distinguish between mass and force but they are both
measured in pounds in the english system.

The "English" system uses the "stone" as the measurement of mass.
The pound ('lb') is the unit of *FORCE*.

Metric is 'much simpler' with grams(mass) and newtons(force).

Evidently *you* think the "English" system is too complicated. ;-)

http://www.engineeringtoolbox.com/ma...ght-d_589.html

I don't think any of them are 'too complicated'.
It is easy enough to convert from one to another.

However, FAILURE to convert has been known to cause problems, such as a
Mars mission that crashed because the wrong units were used.

http://www.cnn.com/TECH/space/9909/30/mars.metric/




--
bz

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

remove ch100-5 to avoid spam trap

In article ,
krw wrote:
In article 39,
says...
NameNotImportant wrote in
m:

lbm?

I'm not sure on your units.

pounds (mass), lbm, as opposed to pounds (force), lbf, or lb.

It is necessary to distinguish between mass and force but they are both
measured in pounds in the english system.

The "English" system uses the "stone" as the measurement of mass.
The pound ('lb') is the unit of *FORCE*.

The 'Stone' is a unit of mass, not "The unit of mass"

All the engineering I ever learned in the British (Imperial) system used
pounds.

Metric is 'much simpler' with grams(mass) and newtons(force).

No - the modern Metric system uses the kilogramme as its fundamental unit.

--
From KT24 - in "Leafy Surrey"

Using a RISC OS computer running v5.11

In article ,
says...
In article ,
krw wrote:
In article 39,
says...
NameNotImportant wrote in
m:

lbm?

I'm not sure on your units.

pounds (mass), lbm, as opposed to pounds (force), lbf, or lb.

It is necessary to distinguish between mass and force but they are both
measured in pounds in the english system.

The "English" system uses the "stone" as the measurement of mass.
The pound ('lb') is the unit of *FORCE*.

The 'Stone' is a unit of mass, not "The unit of mass"

It is *the* unit of mass. The pound-mass is a recent abortion.

All the engineering I ever learned in the British (Imperial) system used
pounds.

You must be a kid.

Metric is 'much simpler' with grams(mass) and newtons(force).

No - the modern Metric system uses the kilogramme as its fundamental unit.

Only if you spell funny.

--
Keith

In article , Anthony Matonak
wrote:
charles wrote:
krw wrote:
says...
It is necessary to distinguish between mass and force but they are
both measured in pounds in the english system.

The "English" system uses the "stone" as the measurement of mass.
The pound ('lb') is the unit of *FORCE*.

The 'Stone' is a unit of mass, not "The unit of mass"

All the engineering I ever learned in the British (Imperial) system
used pounds.

I always thought the British pound was a unit of currency.

cleverly, we use the same word for two different things to confuse
foreigners.

--
From KT24 - in "Leafy Surrey"

Using a RISC OS computer running v5.11

In article ,
krw wrote:
In article ,
says...
In article ,
krw wrote:
In article 39,
says...
NameNotImportant wrote in
m:

lbm?

I'm not sure on your units.

pounds (mass), lbm, as opposed to pounds (force), lbf, or lb.

It is necessary to distinguish between mass and force but they are
both measured in pounds in the english system.

The "English" system uses the "stone" as the measurement of mass.
The pound ('lb') is the unit of *FORCE*.

The 'Stone' is a unit of mass, not "The unit of mass"

It is *the* unit of mass. The pound-mass is a recent abortion.

All the engineering I ever learned in the British (Imperial) system used
pounds.

You must be a kid.


No - 68!!!

Metric is 'much simpler' with grams(mass) and newtons(force).

No - the modern Metric system uses the kilogramme as its fundamental
unit.

Only if you spell funny.

Even in 1961 the MKS system was the norm.

--
From KT24 - in "Leafy Surrey"

Using a RISC OS computer running v5.11

"daestrom" wrote in
:

Trouble with pound-mass (lbm) and pound-force (lbf) is that to make F=MA
work out, you need to keep another 'conversion factor', the dreaded
g-sub-c (g-sub-c = 32.2 lbm-ft / lbf-s^2), around and figure out when to
throw that into the mix.



Really gets to be fun when working with things like foot-pounds,
as in torque, angular momentum, and the pressure due to a certain depth of
water.

Trying to remember when the pounds are mass and when they are force gets
to be fun.



--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

remove ch100-5 to avoid spam trap

In article ,
says...
In article ,
krw wrote:
In article ,
says...
In article ,
krw wrote:
In article 39,
says...
NameNotImportant wrote in
m:

lbm?

I'm not sure on your units.

pounds (mass), lbm, as opposed to pounds (force), lbf, or lb.

It is necessary to distinguish between mass and force but they are
both measured in pounds in the english system.

The "English" system uses the "stone" as the measurement of mass.
The pound ('lb') is the unit of *FORCE*.

The 'Stone' is a unit of mass, not "The unit of mass"

It is *the* unit of mass. The pound-mass is a recent abortion.

All the engineering I ever learned in the British (Imperial) system used
pounds.

You must be a kid.


No - 68!!!

I first heard pound-mass about ten years ago. All through high
school and college the English unit for mass was the stone (as in
the FSF system of measurements).

Metric is 'much simpler' with grams(mass) and newtons(force).

No - the modern Metric system uses the kilogramme as its fundamental
unit.

Only if you spell funny.

Even in 1961 the MKS system was the norm.

Sure, but you still spell like a frog. ;-)

--
Keith

"daestrom" wrote in message
...

"krw" wrote in message
t...
In article ,
says...
In article ,
krw wrote:
In article 39,
says...
NameNotImportant wrote in
m:

lbm?

I'm not sure on your units.

pounds (mass), lbm, as opposed to pounds (force), lbf, or lb.

It is necessary to distinguish between mass and force but they are
both
measured in pounds in the english system.

The "English" system uses the "stone" as the measurement of mass.
The pound ('lb') is the unit of *FORCE*.

The 'Stone' is a unit of mass, not "The unit of mass"

It is *the* unit of mass. The pound-mass is a recent abortion.


If you call the past 100 years or so, 'recent'. I myself have text-books
from the '50's that use this 'recent abortion' as you call it.

Considering the separation of force and mass was first worked out *after*
the original 'pound' for weight was in common use, it was necessary to
separate which 'kind' of 'pound' was being talked about. The one that
represents how much *force* is being applied to something, or the one that
describes how much resistance to acceleration something has.

But for a long time a 'pound' of something was a certain amount of
mass -or- the force applied to a surface by placing that certain amount of
mass on it (such as used in 'dead-weight' testers for pressure
instruments).

In a few obscure bits of engineering, you can even find the term
'kilograms of force' used. Obviously that is the force applied by placing
a kilogram of mass on top of something. You can even find some pressure
gauges calibrated to read 'kg/cm^2'. Proof that you can mess up things
even with the metric system. ;-)

I'm not sure how old the 'stone' is, but I suspect it too was around
before we knew the difference between force and mass. Stone is common in
UK still, but it never caught on in the colonies, even as far back as
colonial days when 'hundredweight' and 'long ton' were in common usage.

Trouble with pound-mass (lbm) and pound-force (lbf) is that to make F=MA
work out, you need to keep another 'conversion factor', the dreaded
g-sub-c (g-sub-c = 32.2 lbm-ft / lbf-s^2), around and figure out when to
throw that into the mix.

daestrom

In the early '50's there were two other units around- the poundal (1/g
pounds force) or a mass called a slug (g pounds mass). Learning mechanics
with these units (don't use them together)is worse than working in the
stone, furlong, fortnight set of units.
The poundal was introduced in 1879 as part of the "english set of units"
(Wikipedia is sometimes useful).
--

Don Kelly
remove the X to answer
----------------------------

daestrom wrote:

"krw" wrote in message
t...
In article ,
says...
In article ,
krw wrote:
In article 39,
says...
NameNotImportant wrote in
m:

lbm?

I'm not sure on your units.

pounds (mass), lbm, as opposed to pounds (force), lbf, or lb.

It is necessary to distinguish between mass and force but they
are both
measured in pounds in the english system.

The "English" system uses the "stone" as the measurement of mass.
The pound ('lb') is the unit of *FORCE*.

The 'Stone' is a unit of mass, not "The unit of mass"

It is *the* unit of mass. The pound-mass is a recent abortion.


If you call the past 100 years or so, 'recent'. I myself have
text-books from the '50's that use this 'recent abortion' as you call it.

Considering the separation of force and mass was first worked out
*after* the original 'pound' for weight was in common use, it was
necessary to separate which 'kind' of 'pound' was being talked about.
The one that represents how much *force* is being applied to something,
or the one that describes how much resistance to acceleration something
has.

But for a long time a 'pound' of something was a certain amount of mass
-or- the force applied to a surface by placing that certain amount of
mass on it (such as used in 'dead-weight' testers for pressure
instruments).

In a few obscure bits of engineering, you can even find the term
'kilograms of force' used. Obviously that is the force applied by
placing a kilogram of mass on top of something. You can even find some
pressure gauges calibrated to read 'kg/cm^2'. Proof that you can mess
up things even with the metric system. ;-)

I'm not sure how old the 'stone' is, but I suspect it too was around
before we knew the difference between force and mass. Stone is common
in UK still, but it never caught on in the colonies, even as far back as
colonial days when 'hundredweight' and 'long ton' were in common usage.

Trouble with pound-mass (lbm) and pound-force (lbf) is that to make F=MA
work out, you need to keep another 'conversion factor', the dreaded
g-sub-c (g-sub-c = 32.2 lbm-ft / lbf-s^2), around and figure out when to
throw that into the mix.

An excellent compilation of measurement units, may be found he

http://www.unc.edu/~rowlett/units/index.html

Note that mass, (kilogram), is the only fundamental unit that is not
defined by a property of nature.

--
Virg Wall, P.E.

krw wrote:

I first heard pound-mass about ten years ago. All through high
school and college the English unit for mass was the stone (as in
the FSF system of measurements).

Is the unit for "Are you getting any lately?", still furlongs per fortnight?

--
Virg Wall

In article MTsXj.145740$Cj7.35522@pd7urf2no,
Don Kelly wrote:



In the early '50's there were two other units around- the poundal (1/g
pounds force) or a mass called a slug (g pounds mass). Learning
mechanics with these units (don't use them together)is worse than
working in the stone, furlong, fortnight set of units. The poundal was
introduced in 1879 as part of the "english set of units" (Wikipedia is
sometimes useful).

I certainly remember the poundal.

The various old english measures: chain, rod, quarter, peck, etc, were, of
course, very useful to teach children arithmetic since they all came with
different bases.

and of course you can measure viscosity in Acres per year - if you want to.

--
From KT24 - in "Leafy Surrey"

Using a RISC OS computer running v5.11

In message , charles
writes
In article MTsXj.145740$Cj7.35522@pd7urf2no,
Don Kelly wrote:



In the early '50's there were two other units around- the poundal (1/g
pounds force) or a mass called a slug (g pounds mass). Learning
mechanics with these units (don't use them together)is worse than
working in the stone, furlong, fortnight set of units. The poundal was
introduced in 1879 as part of the "english set of units" (Wikipedia is
sometimes useful).

I certainly remember the poundal.

The various old english measures: chain, rod, quarter, peck, etc, were, of
course, very useful to teach children arithmetic since they all came with
different bases.

and of course you can measure viscosity in Acres per year - if you want to.

You forgot the poles and perches, the bushels, and of course, the LSD.
--
Ian

In alt.engineering.electrical Anthony Matonak wrote:
| charles wrote:
| krw wrote:
| says...
| It is necessary to distinguish between mass and force but they are both
| measured in pounds in the english system.
|
| The "English" system uses the "stone" as the measurement of mass.
| The pound ('lb') is the unit of *FORCE*.
|
| The 'Stone' is a unit of mass, not "The unit of mass"
|
| All the engineering I ever learned in the British (Imperial) system used
| pounds.
|
| I always thought the British pound was a unit of currency.

That's why I never wanted to carry around the British currency. It can be
quite a chore to carry 50 pounds in your pocket :-)

--
|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) |

wrote:
In alt.engineering.electrical Anthony Matonak wrote:
| charles wrote:
| krw wrote:
| says...
| It is necessary to distinguish between mass and force but they are both
| measured in pounds in the english system.
|
| The "English" system uses the "stone" as the measurement of mass.
| The pound ('lb') is the unit of *FORCE*.
|
| The 'Stone' is a unit of mass, not "The unit of mass"
|
| All the engineering I ever learned in the British (Imperial) system used
| pounds.
|
| I always thought the British pound was a unit of currency.

That's why I never wanted to carry around the British currency. It can be
quite a chore to carry 50 pounds in your pocket :-)

Well, if it's true that "A pint's a pound the world around" then you
don't need to carry it all in your pocket. :-D

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/

In article ,
Morris Dovey wrote:

Well, if it's true that "A pint's a pound the world around" then you
don't need to carry it all in your pocket. :-D

that saying must be some years old.

A pint's now about three pounds ;-(

--
From KT24 - in "Leafy Surrey"

Using a RISC OS computer running v5.11

In article ,
charles writes:
In article ,
Morris Dovey wrote:

Well, if it's true that "A pint's a pound the world around" then you
don't need to carry it all in your pocket. :-D

that saying must be some years old.

A pint's now about three pounds ;-(

Also a US pint (16 fl.oz) is smaller than an Imperial pint (20 fl.oz),
so that would make beer more expensive in the US ;-)

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

Andrew Gabriel wrote:

In article ,
charles writes:
In article ,
Morris Dovey wrote:

Well, if it's true that "A pint's a pound the world around" then you
don't need to carry it all in your pocket. :-D

that saying must be some years old.

A pint's now about three pounds ;-(

Also a US pint (16 fl.oz) is smaller than an Imperial pint (20 fl.oz),
so that would make beer more expensive in the US ;-)


The imperial pint of beer is bigger, because it's still warm. ;-)

--
http://improve-usenet.org/index.html


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

charles writes:


I always thought the British pound was a unit of currency.

cleverly, we use the same word for two different things to confuse
foreigners.


Just wait until you run into BTU's....


--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

Bruce in Bangkok writes:


All distribution transformers, sometimes called "pole pigs", that I
have seen had some sort of voltage adjusting system, usually referred
to as taps. Usually they are an actual bolted "tap" and you open the
transformer and set the output voltage by making the proper tap
connection when the transformer is installed and frankly it is usually
ignored thereafter.

The pole pigs here [7200v in/120-240 out] are fixed tap, I'm told. Saves
money. I think they are fused at 10A in. Older ones may have settable taps.

The other "cans" you often see on poles are capacitors used to adjust
the power factor on some secondaries.

Capacitors are in various places but we also have three 7200V line
regulators a block away, one on each primary phase. They are
auto-transformers, with allegedly auto-controlled tap changers, much as
the other poster described. [But his description is more complex than
I recall from the class covering same. The essential aspect was you
CAN short two taps together while switching; the inductance limits the
current change while you do..]

I say "allegedly" as twice now, the regulators have stuck and my UPS
woke me up at 2:30AM with notices it was disconnecting from the now-128v+
line. I solved the issue that night by putting a Variac in the line
ahead of it, and cranking it down.

It took multiple calls and finally PSC [oversight agency] complaints
to get PEPCO to fix the damn thing.

I envy EU houses. If we had regular 240V/30A+ outlets, I'd be able to
buy a snowblower with real guts. The 120v@15A ones are wimpy.
--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

On Sun, 25 May 2008 21:48:51 +0000 (UTC), David Lesher
wrote:

Bruce in Bangkok writes:


All distribution transformers, sometimes called "pole pigs", that I
have seen had some sort of voltage adjusting system, usually referred
to as taps. Usually they are an actual bolted "tap" and you open the
transformer and set the output voltage by making the proper tap
connection when the transformer is installed and frankly it is usually
ignored thereafter.

The pole pigs here [7200v in/120-240 out] are fixed tap, I'm told. Saves
money. I think they are fused at 10A in. Older ones may have settable taps.

Don't generalize too much. Multi-tap transformers are the normal for rural
co-ops. I have a couple sitting in my shop right now. It's cheaper to change
taps on the transformer than it is to deal with the various voltages that
happen around a large geographic area.

I envy EU houses. If we had regular 240V/30A+ outlets, I'd be able to
buy a snowblower with real guts. The 120v@15A ones are wimpy.

You can have as many of those outlets as you want. In fact, I did just that
in my restaurant. Every place there was an outlet I installed a double ganged
box and included one 20 amp 120 volt outlet and one 30 amp 240 volt outlet.
I'm doing the same thing here in my cabin as I slowly rewire it.

UK appliances are available on the net. A 4kW tea kettle beats the hell out
of a puny 1700 watt 120 volt version. Same with a commercial 240 volt
toaster, coffee maker, etc. All I have to do is change the plug, getting rid
of that UK abomination. Some of the e-stores sell appliances sans plug, aimed
at the european market. The customer installs whatever plug is used in his
country.

For a snow blower, why not make your own? Find one with a blown engine or buy
a new one and sell the engine. Install a suitable electric motor and away you
go. You can figure about 2/3s the HP of the gas engine is necessary for a
normal high torque farm-duty motor.

If I were going to do that, I'd probably go a step further and use a 480 volt
motor along with a 2:1 autotransformer at the house. That way the cord can be
much lighter, something to think about when you're slaving away out in the
white stuff.

Depending on what I could find and at what cost, I might even go with a 3
phase motor and VFD. The VFD will take single phase 240 as input and generate
480 three phase output and at whatever frequency you desire. Considering the
cold operating environment, you could spin a smaller lighter motor faster and
get more power than with a straight 60 hz motor. You could even have a
"throttle" (a potentiometer) on the snowblower. Small VFDs (10 hp and less)
are fairly easy to find used. For that matter, they're not all that expensive
new.

John

--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com -- best little blog on the net!
Tellico Plains, Occupied TN
No one can be right all of the time but I'm getting close.

In alt.engineering.electrical David Lesher wrote:
| Bruce in Bangkok writes:
|
|
|All distribution transformers, sometimes called "pole pigs", that I
|have seen had some sort of voltage adjusting system, usually referred
|to as taps. Usually they are an actual bolted "tap" and you open the
|transformer and set the output voltage by making the proper tap
|connection when the transformer is installed and frankly it is usually
|ignored thereafter.
|
| The pole pigs here [7200v in/120-240 out] are fixed tap, I'm told. Saves
| money. I think they are fused at 10A in. Older ones may have settable taps.
|
|The other "cans" you often see on poles are capacitors used to adjust
|the power factor on some secondaries.
|
| Capacitors are in various places but we also have three 7200V line
| regulators a block away, one on each primary phase. They are
| auto-transformers, with allegedly auto-controlled tap changers, much as
| the other poster described. [But his description is more complex than
| I recall from the class covering same. The essential aspect was you
| CAN short two taps together while switching; the inductance limits the
| current change while you do..]
|
| I say "allegedly" as twice now, the regulators have stuck and my UPS
| woke me up at 2:30AM with notices it was disconnecting from the now-128v+
| line. I solved the issue that night by putting a Variac in the line
| ahead of it, and cranking it down.
|
| It took multiple calls and finally PSC [oversight agency] complaints
| to get PEPCO to fix the damn thing.
|
| I envy EU houses. If we had regular 240V/30A+ outlets, I'd be able to
| buy a snowblower with real guts. The 120v@15A ones are wimpy.

So put one in.

--
|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) |

writes:

| I envy EU houses. If we had regular 240V/30A+ outlets, I'd be able to
| buy a snowblower with real guts. The 120v@15A ones are wimpy.

So put one in.

The issue is not the outlets available in my house [but I sometimes wish
for 3 phase..].

Rather, it's the ready market of consumer appliances that would take
advantage of them. That would require many houses to have them.

--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

David Lesher wrote:
writes:

| I envy EU houses. If we had regular 240V/30A+ outlets, I'd be able to
| buy a snowblower with real guts. The 120v@15A ones are wimpy.

So put one in.

The issue is not the outlets available in my house [but I sometimes wish
for 3 phase..].

Rather, it's the ready market of consumer appliances that would take
advantage of them. That would require many houses to have them.



Get UK/commercial appliances, they're out there.

"James Sweet" wrote in message
news:RYJ_j.5752$0R.3162@trndny05...

David Lesher wrote:
writes:

| I envy EU houses. If we had regular 240V/30A+ outlets, I'd be able to
| buy a snowblower with real guts. The 120v@15A ones are wimpy.

So put one in.

The issue is not the outlets available in my house [but I sometimes wish
for 3 phase..].

Rather, it's the ready market of consumer appliances that would take
advantage of them. That would require many houses to have them.



Get UK/commercial appliances, they're out there.

Yes like my Amana commercial RadarRange which is 4KW in 2.2KW out and has 3
HV magnetrons along with 3 each of the other necessary items (cap, diode,
etc.). It even has a current transformer that tells the control board via
current draw when the magnetrons are warmed up so that the timer doesn't
start counting down until it is actually cooking. It has a standard NEMA
6-20 plug on it now and will pop a bag of popcorn in roughly 75 seconds
without scorching it. I can tell you it sure beats the hell out of regular
microwave ovens for most things. The only thing I still use the regular one
for are items that involve liquids as the Amana tends to make them either
boil over or boils out all of the water before the food is cooked.

Daniel Who Wants to Know wrote:

snip

Yes like my Amana commercial RadarRange which is 4KW in 2.2KW out and has 3
HV magnetrons along with 3 each of the other necessary items (cap, diode,
etc.).

Does this oven somehow injection-lock the magnetrons? Can you describe
the (RF) plumbing?

Michael

In alt.engineering.electrical Daniel Who Wants to Know wrote:

| Yes like my Amana commercial RadarRange which is 4KW in 2.2KW out and has 3
| HV magnetrons along with 3 each of the other necessary items (cap, diode,
| etc.). It even has a current transformer that tells the control board via
| current draw when the magnetrons are warmed up so that the timer doesn't
| start counting down until it is actually cooking. It has a standard NEMA
| 6-20 plug on it now and will pop a bag of popcorn in roughly 75 seconds
| without scorching it. I can tell you it sure beats the hell out of regular
| microwave ovens for most things. The only thing I still use the regular one
| for are items that involve liquids as the Amana tends to make them either
| boil over or boils out all of the water before the food is cooked.

Will it operate on single phase power, like I have in my home?

--
|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) |

James Sweet writes:


Rather, it's the ready market of consumer appliances that would take
advantage of them. That would require many houses to have them.


Get UK/commercial appliances, they're out there.

A Lucas snowblower? It would leak oil, not work when damp,
and plow down the wrong side of the driveway...

And want 50Hz...

--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

In David Lesher writes:

Get UK/commercial appliances, they're out there.

A Lucas snowblower? It would leak oil, not work when damp,
and plow down the wrong side of the driveway...

Still thinking of the British Rail trains that
wouldn't work because (to quote their PIO)
"It was the wrong kind of snow"?

And want 50Hz...

They'd be drooling over 60 Hz.


--
__________________________________________________ ___
Knowledge may be power, but communications is the key

[to foil spammers, my address has been double rot-13 encoded]

On Tue, 27 May 2008 02:03:10 -0500, msg wrote:

Daniel Who Wants to Know wrote:

snip

Yes like my Amana commercial RadarRange which is 4KW in 2.2KW out and has 3
HV magnetrons along with 3 each of the other necessary items (cap, diode,
etc.).

Does this oven somehow injection-lock the magnetrons? Can you describe
the (RF) plumbing?

Can't comment on the microwave oven, though I suspect that it works the same
as my gadget. A couple of years ago I built an EWF (electronic warfare)
device to solve a particularly obnoxious boom-boom stereo problem. This guy
would drive by my restaurant every evening on the way home from work. His
stereo was loud enough to rattle things off my dining room shelves. Talking
to him didn't work soooo...

My gadget used 4 1kw microwave oven magnetrons placed in a suitable waveguide
one wavelength apart, the magnetron antennae simply protruding into the
waveguide. With suitable use of tuning stubs, they phase-locked and the power
added nicely. A quite large rectangular horn terminated the waveguide and
matched it to the ether. I didn't bother with pulsed operation, as the first
CW test was successful :-) Simon and Garfunkel's "The Sound of Silence" song
came to mind.

I had the thing positioned in my dining room, aimed through the plate glass
window at the area behind the stop sign. When he pulled up to the stop sign,
the stereo a-thumping away, I touched the plate supply push button. Instant
silence. Permanent silence. It killed his engine too, but it restarted.

John
--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com -- best little blog on the net!
Tellico Plains, Occupied TN
I don't suffer from insanity, I enjoy every minute of it.

David Lesher writes:

writes:

| I envy EU houses. If we had regular 240V/30A+ outlets, I'd be able to
| buy a snowblower with real guts. The 120v@15A ones are wimpy.

So put one in.

The issue is not the outlets available in my house [but I sometimes wish
for 3 phase..].

Rather, it's the ready market of consumer appliances that would take
advantage of them. That would require many houses to have them.

Yes the inability to go to the nearest WallyWorld and buy a 240V 4kW
cooker/microwave/whatever is a big problem. European appliance could be
got, but I'd worry about anything with a motor (50 Hz), clock (do their
electronic clocks operate off the line frequency like some in the US?),
microwaves (don't they use frequency-dependent constant voltage
transformers?).

David Lesher writes:

The other "cans" you often see on poles are capacitors used to adjust
the power factor on some secondaries.

Capacitors are in various places but we also have three 7200V line
regulators a block away, one on each primary phase. They are
auto-transformers, with allegedly auto-controlled tap changers, much as
the other poster described. [But his description is more complex than
I recall from the class covering same. The essential aspect was you
CAN short two taps together while switching; the inductance limits the
current change while you do..]

I say "allegedly" as twice now, the regulators have stuck and my UPS
woke me up at 2:30AM with notices it was disconnecting from the now-128v+
line. I solved the issue that night by putting a Variac in the line
ahead of it, and cranking it down.

I also asked about tap changers/regulators. Is this what these are, and
if so, are they likely to be manual or automatic?

http://tinyurl.com/534ffq (Google Maps street view of a set of 3 on a pole
in upstate NY. You may have to click on street view and rotate to see them)

In alt.engineering.electrical Michael Moroney wrote:
| David Lesher writes:
|
writes:
|
|| I envy EU houses. If we had regular 240V/30A+ outlets, I'd be able to
|| buy a snowblower with real guts. The 120v@15A ones are wimpy.
|
|So put one in.
|
|The issue is not the outlets available in my house [but I sometimes wish
|for 3 phase..].
|
|Rather, it's the ready market of consumer appliances that would take
|advantage of them. That would require many houses to have them.
|
| Yes the inability to go to the nearest WallyWorld and buy a 240V 4kW
| cooker/microwave/whatever is a big problem. European appliance could be
| got, but I'd worry about anything with a motor (50 Hz), clock (do their
| electronic clocks operate off the line frequency like some in the US?),
| microwaves (don't they use frequency-dependent constant voltage
| transformers?).

It's all chicken and egg.

People don't usually go to the added expense of installing a 240V outlet when
there are hardly any (and none at WallyWorld) 240V appliances.

Appliances are not generally made at power levels requiring 240V, at least for
homes, because there is nowhere to plug it in by default.

BTW, one appliance I am interested in is an electric induction wok. Normally
a wok just doesn't work right used over an electric burner surface. So most
wok cooktops are gas based. However, the induction technology with the right
kind of work actually does work fine on electric power. The catch is it needs
a lot of power. Only the smallest version can run on 120V. All the rest need
240V. Here is the smallest 240V version:

http://www.selectappliance.com/exec/...ct/ck_mwg-2500

And from this, it indicates world plug options for the 240V versions, which
suggests to me the lowest wattage unit isn't marketed outside of 120V parts
of the world (and hence is probably considered a wimpy model intended to at
least work where 240V isn't available).

http://cooktek.com/product_info.php?c=3&s=24&p=12

--
|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) |

(Michael Moroney) writes:


I also asked about tap changers/regulators. Is this what these are, and
if so, are they likely to be manual or automatic?

http://tinyurl.com/534ff (Google Maps street view of a set of 3 on a pole
in upstate NY. You may have to click on street view and rotate to see them)


Yes. Note the primaries are broken by insulators, and there is no
secondary [240/120] service on the pole. [The lowest run is TV coax, then
neutral above it.]

I've never heard of such as manual regulators so I assume they are
automatic.


It's somewhat unusual to see all three on one pole; it must be a BIG
one. Generally I see them staggered on 3 adjacent poles; or two poles
hold a platform between them.


--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433