AC motor voltage conversion?

[mhorowit]

For sale is an aircompressor which required 220v.
Seller states he will convert it to run on 110v.
How will he do that and what are the disadvantages?
Will the motor pull 2x the current? - Mike

[Don W]

mhorowit wrote:
> For sale is an aircompressor which required 220v.
> Seller states he will convert it to run on 110v.
> How will he do that and what are the disadvantages?
> Will the motor pull 2x the current? - Mike
>

Depending on the motor, it may be as simple as
changing a connection inside the control box.
Many units are built to run on either 110V or 220V
with the voltage setting configured at installation.

At 110V, the motor will pull 2x the current that
it does at 220V, and that is normal.

Don W.

[[email protected]]

>At 110V, the motor will pull 2x the current that
>it does at 220V, and that is normal.

Which is why they wire them for 220. It can be a lot.
If you can get 220v to the location, you will be a happy
camper.

Bill Hale

Don W wrote:
> mhorowit wrote:
> > For sale is an aircompressor which required 220v.
> > Seller states he will convert it to run on 110v.
> > How will he do that and what are the disadvantages?
> > Will the motor pull 2x the current? - Mike
> >
>
> Depending on the motor, it may be as simple as
> changing a connection inside the control box.
> Many units are built to run on either 110V or 220V
> with the voltage setting configured at installation.
>
> At 110V, the motor will pull 2x the current that
> it does at 220V, and that is normal.
>
> Don W.

[[email protected]]

Don W wrote:
> mhorowit wrote:
> > For sale is an aircompressor which required 220v.
> > Seller states he will convert it to run on 110v.
> > How will he do that and what are the disadvantages?
> > Will the motor pull 2x the current? - Mike
> >
>
> Depending on the motor, it may be as simple as
> changing a connection inside the control box.
> Many units are built to run on either 110V or 220V
> with the voltage setting configured at installation.
>
> At 110V, the motor will pull 2x the current that
> it does at 220V, and that is normal.
>
> Don W.

[Morgans[_2_]]

" > wrote

> Which is why they wire them for 220. It can be a lot.
> If you can get 220v to the location, you will be a happy
> camper.

I have such an air compressor, and it likes 220 the best. <g>

It starts quicker, and runs a little cooler, when running continuously. It is
possible to run it on a longer extension cord (made up for 220, of course)
without line loss being such an issue.

I have made up an assortment of pigtails to plug into dryer outlets, and welder
outlets. Yes, it is not protecting at the correct amps, but monitored, it is
not much of an issue, I think. A dead short will still kick even a 50 amp
breaker.

If yours is like mine, it pulls almost 15 amps running, and more at start. It
is necessary to have it's own circuit, if you want to run much else with it on
the same circuit.

My vote? Put up with the inconvenience (at times when you are using it away
from the shop) and run it on 220. It should last longer, and be happier.

The wire configuration for both voltages should be pictured on the data plate,
or on the cover where the terminals are, that need to be changed.
--
Jim in NC

[Morgans[_2_]]

"Morgans" > wrote

> If yours is like mine, it pulls almost 15 amps running, and more at start.

I should have included 15 amps running "on 110" to be more precise.
--
Jim in NC

[John Ammeter]

Why does everyone think the voltage is 110/220??

If that actually was the voltage you had in your house you'd be very
unhappy. The nominal voltage is 118/236 with a +/- 5% range so you can
see that 110/220 is actually outside the acceptable range.

John

Morgans wrote:
>
> " > wrote
>
>> Which is why they wire them for 220. It can be a lot.
>> If you can get 220v to the location, you will be a happy
>> camper.
>
>
> I have such an air compressor, and it likes 220 the best. <g>
>
> It starts quicker, and runs a little cooler, when running continuously.
> It is possible to run it on a longer extension cord (made up for 220, of
> course) without line loss being such an issue.
>
> I have made up an assortment of pigtails to plug into dryer outlets, and
> welder outlets. Yes, it is not protecting at the correct amps, but
> monitored, it is not much of an issue, I think. A dead short will still
> kick even a 50 amp breaker.
>
> If yours is like mine, it pulls almost 15 amps running, and more at
> start. It is necessary to have it's own circuit, if you want to run
> much else with it on the same circuit.
>
> My vote? Put up with the inconvenience (at times when you are using it
> away from the shop) and run it on 220. It should last longer, and be
> happier.
>
> The wire configuration for both voltages should be pictured on the data
> plate, or on the cover where the terminals are, that need to be changed.

[Andy Asberry]

On Fri, 17 Nov 2006 19:08:34 -0800, John Ammeter
> wrote:

>Why does everyone think the voltage is 110/220??
>
>If that actually was the voltage you had in your house you'd be very
>unhappy. The nominal voltage is 118/236 with a +/- 5% range so you can
>see that 110/220 is actually outside the acceptable range.
>
>John
>
I remember back in the fifties in vo-ag farm electrification class, it
was emphasized that you should make sure light bulbs were labeled for
120 volt. Perhaps prior to that they were rated 110 or 115? Maybe that
was the line voltage then. What is your take on it?

--Andy Asberry recommends NewsGuy--

[Dave[_5_]]

Leave it set up for 220 and rig yourself up an outlet to plug it into.
The standard residential wiring configuration is for 220 Volts with a
neutral (3 wires). The normal 110 Volt outlets are connected between
one side or the other of the Line and the neutral. Connect from one
side of the Line to the other and you get 220V. If your house is wired
for an electric dryer you have a 220V outlet already - though it may
not be where you want to use the compressor. Get an extension cord with
compatible connectors or have an electrician install a 220V outlet
where you want to use the compressor. If using an existing outlet,
check to ensure that the breaker and wiring are rated for the current
draw of the compressor.

[Morgans[_2_]]

"John Ammeter" > wrote in message
...
> Why does everyone think the voltage is 110/220??
>
> If that actually was the voltage you had in your house you'd be very unhappy.
> The nominal voltage is 118/236 with a +/- 5% range so you can see that 110/220
> is actually outside the acceptable range.

Well, duh, John!

Why is a car called a car?

People (except you and a few others) don't really care what comes squirting out
of their wall plugs, and what to call it, as long as it makes things work.

It isn't 120/240 either. It is way too awkward to call it 118/236, even though
that is most accurate. Calling it 110/220 gets the idea across... Let the
electrical engineers and others that get hung up on exactly what it is, figure
out how to fight convention.

To me, it's still 110/220.

Now, let's get really weird, and figure out what comes out of the plugs at my
school. Three phase, split off to use single phase, now is it Delta or Y? 95%
of the people in the US don't know and don't care. What will they call that
208?
--
Jim in NC

[Jarhead]

"Morgans" > wrote in message
...
|
| "John Ammeter" > wrote in message
| ...
| > Why does everyone think the voltage is 110/220??
| >
| > If that actually was the voltage you had in your house you'd be very
unhappy.
| > The nominal voltage is 118/236 with a +/- 5% range so you can see
that 110/220
| > is actually outside the acceptable range.
|
| Well, duh, John!
|
| Why is a car called a car?
|
| People (except you and a few others) don't really care what comes
squirting out
| of their wall plugs, and what to call it, as long as it makes things
work.
|
| It isn't 120/240 either. It is way too awkward to call it 118/236,
even though
| that is most accurate. Calling it 110/220 gets the idea across... Let
the
| electrical engineers and others that get hung up on exactly what it
is, figure
| out how to fight convention.
|
| To me, it's still 110/220.
|
| Now, let's get really weird, and figure out what comes out of the
plugs at my
| school. Three phase, split off to use single phase, now is it Delta
or Y? 95%
| of the people in the US don't know and don't care. What will they
call that
| 208?
| --
| Jim in NC
|

According to my fuzzy memory Delta is 208 and since there isn't a
neutral or center reference 110 is not available. Y configuration gives
you 220 from leg to leg while from each leg to the common center
(Neutral) gives you 110. From there you go to how the transformers are
configured, I.E. Delta/Delta or Delta/Wye or Wye/Delta. All of which I
do not remember how each effects the voltage result.

--
Jarhead



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[Peter Dohm]

>
> It isn't 120/240 either. It is way too awkward to call it 118/236, even
though
> that is most accurate. Calling it 110/220 gets the idea across... Let the
> electrical engineers and others that get hung up on exactly what it is,
figure
> out how to fight convention.
>
> To me, it's still 110/220.
>
I call it that as well; but I have seen 125.

> Now, let's get really weird, and figure out what comes out of the plugs at
my
> school. Three phase, split off to use single phase, now is it Delta or Y?
95%
> of the people in the US don't know and don't care. What will they call
that
> 208?

I would but that figure closer to 99.5%

I think that's unfortunate, since the easiest way to save money and energy
at the same time is to run motors on three phase power; and three phase Y is
the only place you'll ever see anything properly called 208 volts.

BTW, in my neck of the woods, if you were a major account, you used to get
only open delta unless you paid for the installation of closed delta--and it
was well worth the price!

Peter

[Tater]

John Ammeter wrote:
> Why does everyone think the voltage is 110/220??
>
> If that actually was the voltage you had in your house you'd be very
> unhappy. The nominal voltage is 118/236 with a +/- 5% range so you can
> see that 110/220 is actually outside the acceptable range.
>
> John
>
actually in my travels, ive seen 90-140 volts nominal for the
"standard" 110V outlet. so it is a bit more than 5% tolerance

[John Ammeter]

The service you describe is 120/208V. In the industry where I worked we
called it "Network"... 120/208 3 phase is only used in high density or
commercial areas where the utility has a need for 3 phase for elevators,
motors, etc. It's a Y configuration with 120 degrees between the phases.

Now, out in the hinterlands, the normal configuration is a 120/240 delta
setup. If you want 3 phase there it's a 3 phase delta.

In Seattle, most apartments are 120/208 and most private homes are
120/240, both single phase. A problem happens when a condo/apartment
dweller replaces his electric range with one he bought at a garage sale
or an appliance dealer that doesn't ask the right questions of the
buyer. What do you think happens when you operate a 240 volt device on
208 volts??

Now you know more than you ever wanted to know... amaze and confound
your friends with your newfound knowledge...

John

Morgans wrote:
>
> "John Ammeter" > wrote in message
> ...
>
>> Why does everyone think the voltage is 110/220??
>>
>> If that actually was the voltage you had in your house you'd be very
>> unhappy. The nominal voltage is 118/236 with a +/- 5% range so you can
>> see that 110/220 is actually outside the acceptable range.
>
>
> Well, duh, John!
>
> Why is a car called a car?
>
> People (except you and a few others) don't really care what comes
> squirting out of their wall plugs, and what to call it, as long as it
> makes things work.
>
> It isn't 120/240 either. It is way too awkward to call it 118/236, even
> though that is most accurate. Calling it 110/220 gets the idea
> across... Let the electrical engineers and others that get hung up on
> exactly what it is, figure out how to fight convention.
>
> To me, it's still 110/220.
>
> Now, let's get really weird, and figure out what comes out of the plugs
> at my school. Three phase, split off to use single phase, now is it
> Delta or Y? 95% of the people in the US don't know and don't care.
> What will they call that 208?

[John Ammeter]

Did you ever have your linemen wire up the tickler backwards?? That
gets real interesting when the voltage should be 240/480 open delta. I
had a job where they needed 3 phase for the elevator and only delta was
provided. Thank God it was a 120/240 system because when I wiggied the
voltage at the socket I found over 420 volts (I don't recall the exact
voltage) from one leg to the other. If it had been a 240/480 service
that would have been 840 volts... considered "high voltage" and
decidedly dangerous to the operator, namely ME.

I used that situation on a Test that I was writing for our Utility.
Strangely, only a few people got the question right. We hired a couple
of those fellows.

John

Peter Dohm wrote:
>>It isn't 120/240 either. It is way too awkward to call it 118/236, even
>
> though
>
>>that is most accurate. Calling it 110/220 gets the idea across... Let the
>>electrical engineers and others that get hung up on exactly what it is,
>
> figure
>
>>out how to fight convention.
>>
>>To me, it's still 110/220.
>>
>
> I call it that as well; but I have seen 125.
>
>
>>Now, let's get really weird, and figure out what comes out of the plugs at
>
> my
>
>>school. Three phase, split off to use single phase, now is it Delta or Y?
>
> 95%
>
>>of the people in the US don't know and don't care. What will they call
>
> that
>
>>208?
>
>
> I would but that figure closer to 99.5%
>
> I think that's unfortunate, since the easiest way to save money and energy
> at the same time is to run motors on three phase power; and three phase Y is
> the only place you'll ever see anything properly called 208 volts.
>
> BTW, in my neck of the woods, if you were a major account, you used to get
> only open delta unless you paid for the installation of closed delta--and it
> was well worth the price!
>
> Peter
>
>
>
>

[clare at snyder.on.ca]

On Fri, 17 Nov 2006 19:08:34 -0800, John Ammeter
> wrote:

>Why does everyone think the voltage is 110/220??
>
>If that actually was the voltage you had in your house you'd be very
>unhappy. The nominal voltage is 118/236 with a +/- 5% range so you can
>see that 110/220 is actually outside the acceptable range.
>
>John
>

Officially here it is 115/230 and right now it's 119/238
>Morgans wrote:
>>
>> " > wrote
>>
>>> Which is why they wire them for 220. It can be a lot.
>>> If you can get 220v to the location, you will be a happy
>>> camper.
>>
>>
>> I have such an air compressor, and it likes 220 the best. <g>
>>
>> It starts quicker, and runs a little cooler, when running continuously.
>> It is possible to run it on a longer extension cord (made up for 220, of
>> course) without line loss being such an issue.
>>
>> I have made up an assortment of pigtails to plug into dryer outlets, and
>> welder outlets. Yes, it is not protecting at the correct amps, but
>> monitored, it is not much of an issue, I think. A dead short will still
>> kick even a 50 amp breaker.
>>
>> If yours is like mine, it pulls almost 15 amps running, and more at
>> start. It is necessary to have it's own circuit, if you want to run
>> much else with it on the same circuit.
>>
>> My vote? Put up with the inconvenience (at times when you are using it
>> away from the shop) and run it on 220. It should last longer, and be
>> happier.
>>
>> The wire configuration for both voltages should be pictured on the data
>> plate, or on the cover where the terminals are, that need to be changed.


--
Posted via a free Usenet account from http://www.teranews.com

[clare at snyder.on.ca]

On Fri, 17 Nov 2006 22:59:28 -0600, Andy Asberry >
wrote:

>On Fri, 17 Nov 2006 19:08:34 -0800, John Ammeter
> wrote:
>
>>Why does everyone think the voltage is 110/220??
>>
>>If that actually was the voltage you had in your house you'd be very
>>unhappy. The nominal voltage is 118/236 with a +/- 5% range so you can
>>see that 110/220 is actually outside the acceptable range.
>>
>>John
>>
>I remember back in the fifties in vo-ag farm electrification class, it
>was emphasized that you should make sure light bulbs were labeled for
>120 volt. Perhaps prior to that they were rated 110 or 115? Maybe that
>was the line voltage then. What is your take on it?
>
>--Andy Asberry recommends NewsGuy--

Ontario rural electrification was 135 in the sixties. Urban bulbs
didn't last long if you were on a short line. This was done to make
sure there was a minimum 110 at the end of the line. Not every farm
had it's own transformer back then.

--
Posted via a free Usenet account from http://www.teranews.com

[Morgans[_2_]]

"John Ammeter" > wrote

What do you think happens when you operate a 240 volt device on
> 208 volts??

Lower than rated HP produced, and shorter than normal motor life. Plus, when
you load the motor close to it's limits, the thermal protection or the breakers
kick off. A real pain in the arse.

For those that do not remember, I'm a carpentry teacher at a high school. I
have the 208 single phase power, and prior to me getting there, people bought
220 large power tools, instead of 208. It makes a big difference. I make sure
I order 208 equipment, and things are much happier.
--
Jim in NC

[Peter Dohm]

> Did you ever have your linemen wire up the tickler backwards?? That
> gets real interesting when the voltage should be 240/480 open delta. I
> had a job where they needed 3 phase for the elevator and only delta was
> provided. Thank God it was a 120/240 system because when I wiggied the
> voltage at the socket I found over 420 volts (I don't recall the exact
> voltage) from one leg to the other. If it had been a 240/480 service
> that would have been 840 volts... considered "high voltage" and
> decidedly dangerous to the operator, namely ME.
>
I was actually a radio and tv broadcast tech, and was lucky enough to never
encounter that problem. I say lucky enough because, although we had no
authorization to work on the main wiring of the buildings, there were
opportunities for errors inside our equipment--especially the transmitters.
We tried to be VERY carefull working in there; as the power supplies were
well into the thousands of volts DC, and both accidents and close calls had
occurred in the past.

The open-delta problem had been solved by my predecessor at my first
position as cheif operator, and had caused major reliability problems with
the transmitting equipment until a third transformer was added. He had also
organized a local society of engineers during that same period of time;
which may have been a related fact since the effect of a long run of
open-delta had to seem esoteric to the comptroller when he requested funds
to "purchase" the additional transformer--which would have been roughly
equal to the price of a new car.

Peter

[Robert Bonomi]

In article >,
John Ammeter > wrote:
>Why does everyone think the voltage is 110/220??

Because that *is* what it 'used to be'.

>If that actually was the voltage you had in your house you'd be very
>unhappy. The nominal voltage is 118/236 with a +/- 5% range so you can
>see that 110/220 is actually outside the acceptable range.

Over the years, the 'standard' has changed. *Several* times.

110V

115V

117V

120V

were _all_ the 'standard' over the years -- I have pieces of equipment
with all those voltages on the manufacturer's 'plate'.

In 'common'/casual usage, even when the 'standard' was 115V or 117V,
it was frequently referred to as "110V". In part because of 'mental
inertia' -- the standard had been 110V for a lot of years before the
'nominal' network voltage was raised to 115V. And it wasn't all that
many years before the 'standard' went to 117V, and then on to 120V.

Essentially, it is a 'class label', not an exact value. :)

There's even _more_ 'inertia' with regard to naming of the "2 hots, 180
degree out-of-phase" voltage level. It is *still* not infrequently
referred to as "220" even though the actual line voltage has been much
closer to 240 for 30+ years. A lot of people don't even recognize the
inconsistency of referring to '1 hot' as 120V, and '2 hot' as 220V.

The 'silliness' continues at the next higher voltage step. 'plates' on
gear will likely state (correctly) 480V, but calling it '440V' is still
_very_ common.

"commonly accepted wisdom" is that 110V, 115V, 117V, and 120V all
refer to the same thing, and similarly for 220V, 230V, and 240V.

It's similar to the "fact" that a "12 V battery" typically puts out 13.6V.

[john smith]

In article >,
(Robert Bonomi) wrote:

> 180 degree out-of-phase" voltage level.

Are you certain you don't mean 120- or 240-degrees out of phase?

How does one get two lines 180-degrees out of phase?

[Peter Dohm]

>
> > 180 degree out-of-phase" voltage level.
>
> Are you certain you don't mean 120- or 240-degrees out of phase?
>
> How does one get two lines 180-degrees out of phase?

240V single phase, commonly supplied to single family dwellings, has a
center tap and two hot leads which are 180 degrees out of phase to supply
higher powered items such as air conditioning and electric stoves. In
addition, approximately half of the lower powered items, such as lights and
the refrigerator, are powered by each of the two legs to the center
tap--which is approximately ground potential.

Peter

[[email protected]]

Morgans wrote:
> "John Ammeter" > wrote in message
> ...
> > Why does everyone think the voltage is 110/220??
> >
> > If that actually was the voltage you had in your house you'd be very unhappy.
> > The nominal voltage is 118/236 with a +/- 5% range so you can see that 110/220
> > is actually outside the acceptable range.
>
> Well, duh, John!
>
> Why is a car called a car?

Short for carriage.

Dan

[john smith]

In article >,
"Peter Dohm" > wrote:

> >
> > > 180 degree out-of-phase" voltage level.
> >
> > Are you certain you don't mean 120- or 240-degrees out of phase?
> >
> > How does one get two lines 180-degrees out of phase?
>
> 240V single phase, commonly supplied to single family dwellings, has a
> center tap and two hot leads which are 180 degrees out of phase to supply
> higher powered items such as air conditioning and electric stoves. In
> addition, approximately half of the lower powered items, such as lights and
> the refrigerator, are powered by each of the two legs to the center
> tap--which is approximately ground potential.

Ahhh! But where does the 240 come from?
Does it not come from two of the three legs of a Y or Delta?
These are square root and cube root functions.
If they were 180 out of phase, it would cancel.

[Jarhead]

"T o d d P a t t i s t" > wrote in message
...
| john smith > wrote:
|
|
| >Ahhh! But where does the 240 come from?
| >Does it not come from two of the three legs of a Y or Delta?
|
| It doesn't matter where the 240 comes from, it matters what
| the phase of each wire is relative to some reference. The
| US (and Europe, but at twice the voltage) use a 3-wire,
| single-phase, mid-point neutral distribution system for most
| residential loads. If you use the neutral as the reference,
| then there are two opposite phase wires or split phases. If
| you use the opposite wire as the ref, then there is a single
| phase 240 volt signal.
|
| Commercial sites receive 3-phase power, not single phase.
| The voltage difference between two of the three legs in that
| system is 208 volts, not 240 volts
|
| >These are square root and cube root functions.
|
| No they are not - they are trig functions depending on phase
| angle.
|
| >If they were 180 out of phase, it would cancel.
|
| Phase depends on the reference. You can ignore the neutral
| and just see it as a single phase 240 volt system using
| either hot lead as the reference. If you prefer, you can
| think of one hot lead as being the reference, the neutral as
| having a 120 volt signal on it and the other hot lead as
| having a 240 volt signal in phase with the 120 volt signal
| on the neutral.
|
|
|
|
|
| --
| T o d d P a t t i s t
| (Remove DONTSPAMME from address to email reply.)
|
| Make a commitment to learn something from every flight.
| Share what you learn.

Came across this:

If you have three phase (Y or Wye, which is fairly commonly provided to
businesses or industries but not common in homes) electricity, you can
get a ``sort of'' 240 volt circuit out of it by running between any two
of the three phases. The phase difference is only 120° instead of 180°
so one ends up with only 208 VAC or so between the wires. This is enough
to run most 240 VAC devices simply because the manufacturers aren't
fools and know that Y/Wye supplies are fairly common. This is also true
for a lot of computer equipment that requires 240 VAC (like some racks
or uninterruptible power supplies (UPS) or some big-iron computers).

Taken from this site:
http://www.phy.duke.edu/~rgb/Beowulf/beowulf_book/beowulf_book/node60.html

--
Jarhead





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[Peter Dohm]

> > >
> > > > 180 degree out-of-phase" voltage level.
> > >
> > > Are you certain you don't mean 120- or 240-degrees out of phase?
> > >
> > > How does one get two lines 180-degrees out of phase?
> >
> > 240V single phase, commonly supplied to single family dwellings, has a
> > center tap and two hot leads which are 180 degrees out of phase to
supply
> > higher powered items such as air conditioning and electric stoves. In
> > addition, approximately half of the lower powered items, such as lights
and
> > the refrigerator, are powered by each of the two legs to the center
> > tap--which is approximately ground potential.
>
> Ahhh! But where does the 240 come from?
> Does it not come from two of the three legs of a Y or Delta?
> These are square root and cube root functions.
> If they were 180 out of phase, it would cancel.

They add, rather than cancel, and do come from two legs of a delta.

Remember that the power is transmitted down the street at a much higher
voltage, and the drop to each small cluster of residences is the output of a
transformer with its center-tap referenced to ground potential. The ground
wire, in my part of the country, also serves as the messenger cable
(physical structure) and is the bare wire that you see when you look up at a
typical residential service drop.

Peter

[clare at snyder.on.ca]

On Wed, 22 Nov 2006 20:11:12 GMT, john smith > wrote:

>In article >,
> "Peter Dohm" > wrote:
>
>> >
>> > > 180 degree out-of-phase" voltage level.
>> >
>> > Are you certain you don't mean 120- or 240-degrees out of phase?
>> >
>> > How does one get two lines 180-degrees out of phase?
>>
>> 240V single phase, commonly supplied to single family dwellings, has a
>> center tap and two hot leads which are 180 degrees out of phase to supply
>> higher powered items such as air conditioning and electric stoves. In
>> addition, approximately half of the lower powered items, such as lights and
>> the refrigerator, are powered by each of the two legs to the center
>> tap--which is approximately ground potential.
>
>Ahhh! But where does the 240 come from?
>Does it not come from two of the three legs of a Y or Delta?
>These are square root and cube root functions.
>If they were 180 out of phase, it would cancel.

In north american residential and in most cases rural electricity, the
220 is NOT derived from a delta or wye connected three phase, but from
a simple center tapped power transformer on a single phase line (or
one leg of a three phase line - not 2). 208 is derived from 3 phase,
and is only found in SOME buildings where 3 phase is required for
other purposes, such as multi-unit residential buildings with 3 phase
elevators, or commercial/industrial applications.
Even in many of these situations, a center tapped transformer (single
phase) is used to provide the 120/240 single phase domestic power.(at
least in Ontario Canada)

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