I would like to know what sorts of transformers are suitable for
converting 220v to 440v. Specifically, can I use a step down
transformer in the opposite direction, or will it not work at all due
to losses, etc?

My actual line voltage usually is 240-245 volts.

--
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Iggy,

Transformers are generaly "bi-directional" but work better in the direction
they were designed for.

I would try and get "full power" out of one backwards but it will work.
I've used 110-220 both ways and don "squirly" things with old 70Volt audio
transformers.

--.- Dave



"Ignoramus23731" wrote in message
...
I would like to know what sorts of transformers are suitable for
converting 220v to 440v. Specifically, can I use a step down
transformer in the opposite direction, or will it not work at all due
to losses, etc?

My actual line voltage usually is 240-245 volts.

--
Due to extreme spam originating from Google Groups, and their
inattention
to spammers, I and many others block all articles originating
from Google Groups. If you want your postings to be seen by
more readers you will need to find a different means of
posting on Usenet.
http://improve-usenet.org/

Friggin fingers...
That's a typo.. I meant I WOULDN'T try and get full power.. I usualy derate
about 20%...

I would try and get "full power" out of one backwards but it will work.

--.- Dave


"Dave August" wrote in message
...
Iggy,

Transformers are generaly "bi-directional" but work better in the
direction they were designed for.

I would try and get "full power" out of one backwards but it will work.
I've used 110-220 both ways and don "squirly" things with old 70Volt audio
transformers.

--.- Dave



"Ignoramus23731" wrote in message
...
I would like to know what sorts of transformers are suitable for
converting 220v to 440v. Specifically, can I use a step down
transformer in the opposite direction, or will it not work at all due
to losses, etc?

My actual line voltage usually is 240-245 volts.

--
Due to extreme spam originating from Google Groups, and their
inattention
to spammers, I and many others block all articles originating
from Google Groups. If you want your postings to be seen by
more readers you will need to find a different means of
posting on Usenet.
http://improve-usenet.org/

On 2008-05-30, Dave August wrote:
Iggy,

Transformers are generaly "bi-directional" but work better in the direction
they were designed for.

I would try and get "full power" out of one backwards but it will work.
I've used 110-220 both ways and don "squirly" things with old 70Volt audio
transformers.

What I am afraid, is that out of this 440-220 transformer, I would get
not 440v, but maybe 420 volts.

i

Ignoramus23731 wrote:

I would like to know what sorts of transformers are suitable for
converting 220v to 440v. Specifically, can I use a step down
transformer in the opposite direction, or will it not work at all due
to losses, etc?

Well I'd want one rated for the voltage I'm using. Then there is KVA
rating. That has to be up to what you are trying to power. Higher power,
to problem. 50 cycle, no problem.

I have never run into a warning that a transformer is only suitable for
going one way.

The only issue I'd be concerned about is using a way bigger transformer than
needed. Hysterisis losses might be high.

Wes

Ignoramus23731 wrote:
On 2008-05-30, Dave August wrote:
Iggy,

Transformers are generaly "bi-directional" but work better in the
direction they were designed for.

I would try and get "full power" out of one backwards but it will
work. I've used 110-220 both ways and don "squirly" things with old
70Volt audio transformers.

What I am afraid, is that out of this 440-220 transformer, I would get
not 440v, but maybe 420 volts.



Should be easy enough to check.
You also ought to be able to change the taps around to get plus or minus
five percent or so on the output.
I'm assuming a three phase IO here.

--

John R. Carroll
www.machiningsolution.com

Unless there is some serious Hysterisis loss, you'll get the 2-1 the
transformer is wound for.

Hook it up and see.

--.- Dave

"Ignoramus23731" wrote in message
...
On 2008-05-30, Dave August wrote:
Iggy,

Transformers are generaly "bi-directional" but work better in the
direction
they were designed for.

I would try and get "full power" out of one backwards but it will work.
I've used 110-220 both ways and don "squirly" things with old 70Volt
audio
transformers.

What I am afraid, is that out of this 440-220 transformer, I would get
not 440v, but maybe 420 volts.

i

Ignoramus23731 wrote:

What I am afraid, is that out of this 440-220 transformer, I would get
not 440v, but maybe 420 volts.


I think 10 percent variation is normal. Some transformers have voltage
adjustment taps. I personally prefer a bit high over a bit low.

Wes

Ignoramus23731 wrote:
I would like to know what sorts of transformers are suitable for
converting 220v to 440v. Specifically, can I use a step down
transformer in the opposite direction, or will it not work at all due
to losses, etc?

My actual line voltage usually is 240-245 volts.

Sure they will work backwards but the flux leakage will be a tad
higher so derate a little 15 or 20 % .
...lew...

Ignoramus23731 wrote:

I would like to know what sorts of transformers are suitable for
converting 220v to 440v. Specifically, can I use a step down
transformer in the opposite direction, or will it not work at all due
to losses, etc?

My actual line voltage usually is 240-245 volts.

--
Due to extreme spam originating from Google Groups, and their inattention
to spammers, I and many others block all articles originating
from Google Groups. If you want your postings to be seen by
more readers you will need to find a different means of
posting on Usenet.
http://improve-usenet.org/


http://www.federalpacific.com/univer...niversity.html

On 2008-05-30, John R. Carroll jcarroll@ubu wrote:
Ignoramus23731 wrote:
On 2008-05-30, Dave August wrote:
Iggy,

Transformers are generaly "bi-directional" but work better in the
direction they were designed for.

I would try and get "full power" out of one backwards but it will
work. I've used 110-220 both ways and don "squirly" things with old
70Volt audio transformers.

What I am afraid, is that out of this 440-220 transformer, I would get
not 440v, but maybe 420 volts.



Should be easy enough to check.
You also ought to be able to change the taps around to get plus or minus
five percent or so on the output.
I'm assuming a three phase IO here.


Just one phase.

--
Due to extreme spam originating from Google Groups, and their inattention
to spammers, I and many others block all articles originating
from Google Groups. If you want your postings to be seen by
more readers you will need to find a different means of
posting on Usenet.
http://improve-usenet.org/

"Ignoramus23731"
wrote in
message
Just one phase.

Just curious---what the heck runs on 440 single
phase?

On May 30, 2:37*pm, "Dave August" wrote:
Iggy,

Transformers are generaly "bi-directional" but work better in the direction
they were designed for.

I would try and get "full power" out of one backwards but it will work.
I've used 110-220 both ways and don "squirly" things with old 70Volt audio
transformers.

--.- Dave

"Ignoramus23731" wrote in message

...



I would like to know what sorts of transformers are suitable for
converting 220v to 440v. Specifically, can I use a step down
transformer in the opposite direction, or will it not work at all due
to losses, etc?

My actual line voltage usually is 240-245 volts.

--
* Due to extreme spam originating from Google Groups, and their
inattention
* * *to spammers, I and many others block all articles originating
* * * from Google Groups. If you want your postings to be seen by
* * * * more readers you will need to find a different means of
* * * * * * * * * * * posting on Usenet.
* * * * * * * * *http://improve-usenet.org/- Hide quoted text -

- Show quoted text -

Could you explain more on this aspect of "transformers work better one
way versus the other"?

If one stays within the voltage and ampere ratings, any transformer
should work either direction.

TMT

On 2008-05-31, BillM wrote:

"Ignoramus23731"
wrote in
message
Just one phase.

Just curious---what the heck runs on 440 single
phase?

An old Hypertherm 600 plasma cutter.

--
Due to extreme spam originating from Google Groups, and their inattention
to spammers, I and many others block all articles originating
from Google Groups. If you want your postings to be seen by
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posting on Usenet.
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On Sat, 31 May 2008 03:50:54 GMT, with neither quill nor qualm,
"BillM" quickly quoth:


"Ignoramus23731"
wrote in
message
Just one phase.

Just curious---what the heck runs on 440 single
phase?

VERY fast motors, well, for a couple seconds, anyway.

--

To change one's self is sufficient. It's the idiots who want to change
the world who are causing all the trouble --Anonymous

On May 30, 6:06*pm, Ignoramus23731 ignoramus23...@NOSPAM.
23731.invalid wrote:

What I am afraid, is that out of this 440-220 transformer, I would get
not 440v, but maybe 420 volts.
i

http://en.wikipedia.org/wiki/Buck-boost_transformer

Jim Wilkins

Ignoramus23731 wrote:

On 2008-05-31, BillM wrote:

"Ignoramus23731"
wrote in
message
Just one phase.

Just curious---what the heck runs on 440 single
phase?

An old Hypertherm 600 plasma cutter.

Also useful for testing 440V VFDs presuming you have a 3 phase motor
that can be strapped for 440V to go on the output of the VFD.

On May 30, 9:51 pm, Too_Many_Tools wrote:



Could you explain more on this aspect of "transformers work better one
way versus the other"?

If one stays within the voltage and ampere ratings, any transformer
should work either direction.

TMT

Transformers will work both directions. However they are usually
designed to boost the voltage slightly to compensate for the drop in
voltage due to the resistance in the windings. So a 120 to 240 volt
transformer with 120 volts in, might put out 243 volts with no load
and 240 volts when loaded.

Dan

In article yW30k.815$BV.422@trndny05, "BillM"
wrote:

"Ignoramus23731"
wrote in
message
Just one phase.

Just curious---what the heck runs on 440 single
phase?

A 440 volt VFD that then powers a 440 v 3 phase motor?

Many or most 3-phase input VFDs can be wired for single-phase input, at
some expense in derating.

Joe Gwinn

In article ,
Ignoramus23731 wrote:

On 2008-05-31, BillM wrote:

"Ignoramus23731"
wrote in
message
Just one phase.

Just curious---what the heck runs on 440 single
phase?

An old Hypertherm 600 plasma cutter.

If memory serves, at 440 one cannot use any direct action switches, and
must instead use contactors in well-grounded metal boxes to turn things
on and off.

Joe Gwinn

Lew Hartswick wrote:

Sure they will work backwards but the flux leakage will be a tad
higher so derate a little 15 or 20 % .

Do you have a reference to that? Always interested in learning something.

Wes

So when you put in 240 on the 220 input the losses might be ok.
It depends on the 'regulation' of the transformer - how tightly
the two windings are to each other.

Many transformers have multiple taps on the input and/or output for
line regulation correction...

Martin

Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/


Ignoramus23731 wrote:
On 2008-05-30, Dave August wrote:
Iggy,

Transformers are generaly "bi-directional" but work better in the direction
they were designed for.

I would try and get "full power" out of one backwards but it will work.
I've used 110-220 both ways and don "squirly" things with old 70Volt audio
transformers.

What I am afraid, is that out of this 440-220 transformer, I would get
not 440v, but maybe 420 volts.

i


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http://www.pronews.com The #1 Newsgroup Service in the World! 100,000 Newsgroups
---= - Total Privacy via Encryption =---

Wes -

Think of transforms - they can be designed in many configurations.

Some have loose windings and others have tight coupling between them.

They can be in I, H, 8 or other configurations. I have seen single phase
in complex modes that have internal boost/bucking windings to add or subtract.

If a winding is wound over another, the outer winding will have less magnetic
field than the one on the metal itself.

I have a set of 6 transforms in my shop. I step up and boost the three phases
I generate from a rotary 220 unit. My transformers are over sized from what
I did as I over engineered it for two machines running full bore.
I use one not two. And I run 1 or 2 motors not 3 on that one.

Martin

Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
TSRA, Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Founder
IHMSA and NRA Metallic Silhouette maker & member.
http://lufkinced.com/


Wes wrote:
Lew Hartswick wrote:

Sure they will work backwards but the flux leakage will be a tad
higher so derate a little 15 or 20 % .

Do you have a reference to that? Always interested in learning something.

Wes


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http://www.pronews.com The #1 Newsgroup Service in the World! 100,000 Newsgroups
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Wes wrote:

Lew Hartswick wrote:

Sure they will work backwards but the flux leakage will be a tad
higher so derate a little 15 or 20 % .

Do you have a reference to that? Always interested in learning something.

Wes
The primaries are wound next tothe core with secondaries on top
so reversing the windings will do that.
We are talking about E I laminated cores.
...lew...

On May 31, 7:53*am, " wrote:
On May 30, 9:51 pm, Too_Many_Tools wrote:

Could you explain more on this aspect of "transformers work better one
way versus the other"?

If one stays within the voltage and ampere ratings, any transformer
should work either direction.

TMT

Transformers will work both directions. *However they are usually
designed to boost the voltage slightly to compensate for the drop in
voltage due to the resistance in the windings. *So a 120 to 240 volt
transformer with 120 volts in, might put out 243 volts with no load
and 240 volts when loaded.

* * * * * * * * * * * * * * * * * * * * * * * * * * *Dan

Thanks Dan...this I understand.

TMT

On Sat, 31 May 2008, "BillM" wrote:
"Ignoramus23731" wrote in message

Just one phase.

Just curious---what the heck runs on 440 single
phase?

Not a whole lot - But if you have 277V/480V 3-Phase 4-Wire Wye
service there's a LOT that runs off a single 277V leg to Neutral.
Overhead fluorescent and HID lighting, Emergency and EXIT lights,
parking lot HID pole lights, and a lot more.

You can cover a 5,000 foot warehouse with two or three circuits of
high-bay lighting at 277V or 10 circuits at 120V. Makes it go
together a lot faster and easier, and a lot less wire.

-- Bruce --

Lew Hartswick wrote:

The primaries are wound next tothe core with secondaries on top
so reversing the windings will do that.
We are talking about E I laminated cores.
...lew...

Ah, I seem to remember that the primary on my Sansui 8080db receiver was the
first winding. Sure didn't care for having to rewind the darn thing, damn
idiot they moved into my room in the barracks saw a stereo that was
unplugged and just had to plug it in. Power transistors were out due to
failure and the leads to them were loose. D*ckhead managed to fry the
transformer.

Not sure where the First Sergeant transferred this jerk to, hope it sucked.

Wes

On Fri, 30 May 2008 17:06:56 -0500, Ignoramus23731
wrote:

On 2008-05-30, Dave August wrote:
Iggy,

Transformers are generaly "bi-directional" but work better in the direction
they were designed for.

I would try and get "full power" out of one backwards but it will work.
I've used 110-220 both ways and don "squirly" things with old 70Volt audio
transformers.

What I am afraid, is that out of this 440-220 transformer, I would get
not 440v, but maybe 420 volts.

i

Even if you do..that 20 volts ..in the grand scheme of things..really
wont mean **** at 400+ volts


Gunner