Does anyone know where to find a surplused 240V to 480V 3 phase step
up transformer at around the 15 Kva range. I need one to power off of
my 15HP RPC to run my 480V 3 phase B&S Vertical mill. Los Angles,
Orange County, Inland Empire or San Diego area would be great. Don't
want to pay shipping for this weighty item ya know. Thanks.

trg-s338

"trg-s338" wrote in message
...
Does anyone know where to find a surplused 240V to 480V 3 phase step
up transformer at around the 15 Kva range. I need one to power off of
my 15HP RPC to run my 480V 3 phase B&S Vertical mill. Los Angles,
Orange County, Inland Empire or San Diego area would be great. Don't
want to pay shipping for this weighty item ya know. Thanks.

trg-s338

See Winston's Laws. I got one cheap, a sittin' in the grave. Only 2500 miles
away/

Karl

I have one for sale.



i

On 2009-05-26, trg-s338 wrote:
Does anyone know where to find a surplused 240V to 480V 3 phase step
up transformer at around the 15 Kva range. I need one to power off of
my 15HP RPC to run my 480V 3 phase B&S Vertical mill. Los Angles,
Orange County, Inland Empire or San Diego area would be great. Don't
want to pay shipping for this weighty item ya know. Thanks.

trg-s338

Karl Townsend wrote:
"trg-s338" wrote in message
...
Does anyone know where to find a surplused 240V to 480V 3 phase step
up transformer at around the 15 Kva range. I need one to power off of
my 15HP RPC to run my 480V 3 phase B&S Vertical mill. Los Angles,
Orange County, Inland Empire or San Diego area would be great. Don't
want to pay shipping for this weighty item ya know. Thanks.

trg-s338

See Winston's Laws. I got one cheap, a sittin' in the grave. Only 2500 miles
away/

(Snort!)

--Winston

On Tue, 26 May 2009 15:33:43 -0700 (PDT), trg-s338
wrote:

Does anyone know where to find a surplused 240V to 480V 3 phase step
up transformer at around the 15 Kva range. I need one to power off of
my 15HP RPC to run my 480V 3 phase B&S Vertical mill. Los Angles,
Orange County, Inland Empire or San Diego area would be great. Don't
want to pay shipping for this weighty item ya know. Thanks.

trg-s338

How about a 480 step DOWN transformer and simply turn it around
backwards?

I may have some. Ill check tommorow.

Worst comes to worst..call Rito at Unicorn Metals in La Habra and ask
him for one.

http://www.unicornmetals.com/

There may be MANY of them available in So. Cal with all the shops going
tits up.

Gunner

"Lenin called them "useful idiots," those people living in
liberal democracies who by giving moral and material support
to a totalitarian ideology in effect were braiding the rope that
would hang them. Why people who enjoyed freedom and prosperity worked
passionately to destroy both is a fascinating question, one still with us
today. Now the useful idiots can be found in the chorus of appeasement,
reflexive anti-Americanism, and sentimental idealism trying to inhibit
the necessary responses to another freedom-hating ideology, radical Islam"

Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno

Gunner Asch fired this volley in
:

How about a 480 step DOWN transformer and simply turn it around
backwards?


Due to core losses, copper losses, et. al., it won't work at the 2:1
ratio in reverse.

LLoyd

On Tue, 26 May 2009 19:18:37 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Gunner Asch fired this volley in
:

How about a 480 step DOWN transformer and simply turn it around
backwards?


Due to core losses, copper losses, et. al., it won't work at the 2:1
ratio in reverse.

LLoyd


Odd..I do it regularly.

Shrug...

Gunner

"Lenin called them "useful idiots," those people living in
liberal democracies who by giving moral and material support
to a totalitarian ideology in effect were braiding the rope that
would hang them. Why people who enjoyed freedom and prosperity worked
passionately to destroy both is a fascinating question, one still with us
today. Now the useful idiots can be found in the chorus of appeasement,
reflexive anti-Americanism, and sentimental idealism trying to inhibit
the necessary responses to another freedom-hating ideology, radical Islam"

Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com writes:


How about a 480 step DOWN transformer and simply turn it around
backwards?


Due to core losses, copper losses, et. al., it won't work at the 2:1
ratio in reverse.

Oh? That's news to me...

I know of no reason you can't do exactly that, and have done
so at lower power levels.


--
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

Gunner Asch fired this volley in
:


Odd..I do it regularly.

What, at no load? Gunner, I worked for a couple of years in the
design and testing lab of Florida Transitron. I know just a bit about
them, and have made many from scrapped parts of others, since.

A 2:1 step-down transformer is NOT wound precisely to 2:1 ratio,
unless it's: 1)so lightly loaded as to constitute virtually no load at
all, or 2) working at much higher frequencies than 60Hz (and even then
loading plays a factor).

I know you don't understand that the secondary has resistance, or that
the core has hysteresis losses; but they do.

(Gunner... again!)

LLoyd

David Lesher fired this volley in news:gvi3nb$2i8$1
@reader1.panix.com:

I know of no reason you can't do exactly that, and have done
so at lower power levels.

Ignorance doesn't make it work properly.

Sorry, but you and Gunner are reading off the same page, and it's not
even in the electronics book.

LLoyd

On Tue, 26 May 2009 20:11:52 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Gunner Asch fired this volley in
:


Odd..I do it regularly.

What, at no load? Gunner, I worked for a couple of years in the
design and testing lab of Florida Transitron. I know just a bit about
them, and have made many from scrapped parts of others, since.

A 2:1 step-down transformer is NOT wound precisely to 2:1 ratio,
unless it's: 1)so lightly loaded as to constitute virtually no load at
all, or 2) working at much higher frequencies than 60Hz (and even then
loading plays a factor).

Or 3) if it's in the size range being discussed here. The turns ratio
is tweaked in smaller dry-type transformers, but is equal to the
voltage ratio in larger units. The transition point varies between
manufacturers: Acme compensates single phase xfomers below 1 kVA and 3
phase units below 15 kVA; Hammond drops the compensation at 3 and 6
kVA.

You do need to pay extra attention to the actual internal connections
in 3 phase xformers when reverse connecting.

--
Ned Simmons

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com writes:


I know of no reason you can't do exactly that, and have done
so at lower power levels.

Ignorance doesn't make it work properly.

Sorry, but you and Gunner are reading off the same page, and it's not
even in the electronics book.

Well, I got an A in EE421; and was proud of it. Granted it was 20+ years
ago, but last I heard Maxwell, RH rule and that guy Thevenin still hold
to this day.

Sure there are losses, all kinds of losses.. We got copper resistance
losses, we got eddy current losses, you name it. But I don't recall any
reason they don't apply no matter which way you go. Can you cite a source
to back you up?




--
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 Tue, 26 May 2009 20:11:52 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Gunner Asch fired this volley in
:


Odd..I do it regularly.

What, at no load? Gunner, I worked for a couple of years in the
design and testing lab of Florida Transitron. I know just a bit about
them, and have made many from scrapped parts of others, since.

A 2:1 step-down transformer is NOT wound precisely to 2:1 ratio,
unless it's: 1)so lightly loaded as to constitute virtually no load at
all, or 2) working at much higher frequencies than 60Hz (and even then
loading plays a factor).

I know you don't understand that the secondary has resistance, or that
the core has hysteresis losses; but they do.

(Gunner... again!)

LLoyd

Blink blink...so none of the transformers Ive installed are working?

Damn....bunch of miracle machines!!!!!

Gunner

"Lenin called them "useful idiots," those people living in
liberal democracies who by giving moral and material support
to a totalitarian ideology in effect were braiding the rope that
would hang them. Why people who enjoyed freedom and prosperity worked
passionately to destroy both is a fascinating question, one still with us
today. Now the useful idiots can be found in the chorus of appeasement,
reflexive anti-Americanism, and sentimental idealism trying to inhibit
the necessary responses to another freedom-hating ideology, radical Islam"

Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno

On Tue, 26 May 2009 21:55:49 -0400, Ned Simmons wrote:

On Tue, 26 May 2009 20:11:52 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

Gunner Asch fired this volley in
m:


Odd..I do it regularly.

What, at no load? Gunner, I worked for a couple of years in the
design and testing lab of Florida Transitron. I know just a bit about
them, and have made many from scrapped parts of others, since.

A 2:1 step-down transformer is NOT wound precisely to 2:1 ratio,
unless it's: 1)so lightly loaded as to constitute virtually no load at
all, or 2) working at much higher frequencies than 60Hz (and even then
loading plays a factor).

Or 3) if it's in the size range being discussed here. The turns ratio
is tweaked in smaller dry-type transformers, but is equal to the
voltage ratio in larger units. The transition point varies between
manufacturers: Acme compensates single phase xfomers below 1 kVA and 3
phase units below 15 kVA; Hammond drops the compensation at 3 and 6
kVA.

You do need to pay extra attention to the actual internal connections
in 3 phase xformers when reverse connecting.


Yes you do. And you have to adjust the voltage bars carefully to insure
the proper output voltage.

Gunner

"Lenin called them "useful idiots," those people living in
liberal democracies who by giving moral and material support
to a totalitarian ideology in effect were braiding the rope that
would hang them. Why people who enjoyed freedom and prosperity worked
passionately to destroy both is a fascinating question, one still with us
today. Now the useful idiots can be found in the chorus of appeasement,
reflexive anti-Americanism, and sentimental idealism trying to inhibit
the necessary responses to another freedom-hating ideology, radical Islam"

Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno

On Tue, 26 May 2009 20:13:15 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

David Lesher fired this volley in news:gvi3nb$2i8$1
:

I know of no reason you can't do exactly that, and have done
so at lower power levels.

Ignorance doesn't make it work properly.

Sorry, but you and Gunner are reading off the same page, and it's not
even in the electronics book.

LLoyd


google "using a step down transformer in reverse"

Results...96,800 hits

Shrug, believe what you wish to.
You are still wrong. Shrug.

Gunner

"Lenin called them "useful idiots," those people living in
liberal democracies who by giving moral and material support
to a totalitarian ideology in effect were braiding the rope that
would hang them. Why people who enjoyed freedom and prosperity worked
passionately to destroy both is a fascinating question, one still with us
today. Now the useful idiots can be found in the chorus of appeasement,
reflexive anti-Americanism, and sentimental idealism trying to inhibit
the necessary responses to another freedom-hating ideology, radical Islam"

Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno

On May 26, 5:18*pm, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:
Gunner Asch fired this volley :

How about a 480 step DOWN transformer and simply turn it around
backwards?

Due to core losses, copper losses, et. al., it won't work at the 2:1
ratio in reverse.

LLoyd

Hi, Lloyd.
The voltage ratios have to be the same, either direction, as they are
physical quantities(turns counts). What doesn't work it the KVA
rating, according to the electrician that installed the transformer to
operate our convection oven for soldering circuit boards. He said to
de-rate the KVA 10%. We have been running a transformer backwards to
get 480 from 208 for about 4 years, now. 24/7.

Paul

On Wed, 27 May 2009 03:17:36 +0000 (UTC), David Lesher
wrote:

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com writes:


I know of no reason you can't do exactly that, and have done
so at lower power levels.

Ignorance doesn't make it work properly.

Sorry, but you and Gunner are reading off the same page, and it's not
even in the electronics book.

Well, I got an A in EE421; and was proud of it. Granted it was 20+ years
ago, but last I heard Maxwell, RH rule and that guy Thevenin still hold
to this day.

Sure there are losses, all kinds of losses.. We got copper resistance
losses, we got eddy current losses, you name it. But I don't recall any
reason they don't apply no matter which way you go. Can you cite a source
to back you up?

Easy thar, fellas, this ain't politics. All of you are right.

Xfmrs with smaller VA or KVA ratings are designed with a bit of fudge
factor so they'll deliver rated voltage at rated load in spite of
droop at rated load. Larger xfmrs are designed to have negligible
droop at rated load because to do otherwise would result in
unacceptable inefficiency and heating.

On Tue, 26 May 2009 21:14:32 -0700 (PDT), KD7HB
wrote:

On May 26, 5:18*pm, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:
Gunner Asch fired this volley :

How about a 480 step DOWN transformer and simply turn it around
backwards?

Due to core losses, copper losses, et. al., it won't work at the 2:1
ratio in reverse.

LLoyd

Hi, Lloyd.
The voltage ratios have to be the same, either direction, as they are
physical quantities(turns counts). What doesn't work it the KVA
rating, according to the electrician that installed the transformer to
operate our convection oven for soldering circuit boards. He said to
de-rate the KVA 10%. We have been running a transformer backwards to
get 480 from 208 for about 4 years, now. 24/7.

Paul

Ayup. I always calculate -20%

Gunner

"Lenin called them "useful idiots," those people living in
liberal democracies who by giving moral and material support
to a totalitarian ideology in effect were braiding the rope that
would hang them. Why people who enjoyed freedom and prosperity worked
passionately to destroy both is a fascinating question, one still with us
today. Now the useful idiots can be found in the chorus of appeasement,
reflexive anti-Americanism, and sentimental idealism trying to inhibit
the necessary responses to another freedom-hating ideology, radical Islam"

Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno

On May 26, 4:28*pm, Gunner Asch wrote:
On Tue, 26 May 2009 15:33:43 -0700 (PDT), trg-s338

wrote:
Does anyone know where to find a surplused 240V to 480V 3 phase step
up transformer at around the 15 Kva range. *I need one to power off of
my 15HP RPC to run my 480V 3 phase B&S Vertical mill. *Los Angles,
Orange County, Inland Empire or San Diego area would be great. *Don't
want to pay shipping for this weighty item ya know. *Thanks.

trg-s338

How about a 480 step DOWN transformer and simply turn it around
backwards?

I may have some. Ill check tommorow.

Worst comes to worst..call Rito at Unicorn Metals in La Habra and ask
him for one.

http://www.unicornmetals.com/

There may be MANY of them available in So. Cal with all the shops going
tits up.

Gunner

Gunner,

Let me know what you have please, before I check with Unicorn Metals.

Manny

On May 26, 10:00*pm, Gunner Asch wrote:
On Tue, 26 May 2009 21:14:32 -0700 (PDT), KD7HB
wrote:



On May 26, 5:18*pm, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:
Gunner Asch fired this volley :

How about a 480 step DOWN transformer and simply turn it around
backwards?

Due to core losses, copper losses, et. al., it won't work at the 2:1
ratio in reverse.

LLoyd

Hi, Lloyd.
The voltage ratios have to be the same, either direction, as they are
physical quantities(turns counts). What doesn't work it the KVA
rating, according to the electrician that installed the transformer to
operate our convection oven for soldering circuit boards. He said to
de-rate the KVA 10%. We have been running a transformer backwards to
get 480 from 208 for about 4 years, now. 24/7.

Paul

Ayup. I always calculate -20%

Gunner


If a step down transformer is used in reverse, how would one ground
the secondary (which now acts as primary)?

On Tue, 26 May 2009 23:25:33 -0700 (PDT), trg-s338
wrote:

On May 26, 10:00*pm, Gunner Asch wrote:
On Tue, 26 May 2009 21:14:32 -0700 (PDT), KD7HB
wrote:



On May 26, 5:18*pm, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:
Gunner Asch fired this volley :

How about a 480 step DOWN transformer and simply turn it around
backwards?

Due to core losses, copper losses, et. al., it won't work at the 2:1
ratio in reverse.

LLoyd

Hi, Lloyd.
The voltage ratios have to be the same, either direction, as they are
physical quantities(turns counts). What doesn't work it the KVA
rating, according to the electrician that installed the transformer to
operate our convection oven for soldering circuit boards. He said to
de-rate the KVA 10%. We have been running a transformer backwards to
get 480 from 208 for about 4 years, now. 24/7.

Paul

Ayup. I always calculate -20%

Gunner


If a step down transformer is used in reverse, how would one ground
the secondary (which now acts as primary)?


You mean besides using that big green tab located on the frame of the
transformer?

Or something else?

You do realize we are talking about 3ph transformers...right?

Gunner

"Lenin called them "useful idiots," those people living in
liberal democracies who by giving moral and material support
to a totalitarian ideology in effect were braiding the rope that
would hang them. Why people who enjoyed freedom and prosperity worked
passionately to destroy both is a fascinating question, one still with us
today. Now the useful idiots can be found in the chorus of appeasement,
reflexive anti-Americanism, and sentimental idealism trying to inhibit
the necessary responses to another freedom-hating ideology, radical Islam"

Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno

On Tue, 26 May 2009 22:19:22 -0700 (PDT), trg-s338
wrote:

On May 26, 4:28*pm, Gunner Asch wrote:
On Tue, 26 May 2009 15:33:43 -0700 (PDT), trg-s338

wrote:
Does anyone know where to find a surplused 240V to 480V 3 phase step
up transformer at around the 15 Kva range. *I need one to power off of
my 15HP RPC to run my 480V 3 phase B&S Vertical mill. *Los Angles,
Orange County, Inland Empire or San Diego area would be great. *Don't
want to pay shipping for this weighty item ya know. *Thanks.

trg-s338

How about a 480 step DOWN transformer and simply turn it around
backwards?

I may have some. Ill check tommorow.

Worst comes to worst..call Rito at Unicorn Metals in La Habra and ask
him for one.

http://www.unicornmetals.com/

There may be MANY of them available in So. Cal with all the shops going
tits up.

Gunner

Gunner,

Let me know what you have please, before I check with Unicorn Metals.

Manny

It will be Friday before I can get back with you..more than
likely..Saturday morning. Ive got to be in Anaheim at 7am and start
tearing down a BIG factory. Ill be down there until its done..cause
they have to be out by the 9th.

If your not in a hurry..Ill do it for you.

Hell..I may have some from this factory. Ive got to clear the entire
100,000 square foot out.


Gunner

"Lenin called them "useful idiots," those people living in
liberal democracies who by giving moral and material support
to a totalitarian ideology in effect were braiding the rope that
would hang them. Why people who enjoyed freedom and prosperity worked
passionately to destroy both is a fascinating question, one still with us
today. Now the useful idiots can be found in the chorus of appeasement,
reflexive anti-Americanism, and sentimental idealism trying to inhibit
the necessary responses to another freedom-hating ideology, radical Islam"

Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno

Gunner Asch fired this volley in
:

And you have to adjust the voltage bars carefully to insure
the proper output voltage.



You just confirmed my original statement. You never mentioned it's
being a stepped secondary -- just "2:1 step-down".

LLoyd

On May 27, 5:14*am, KD7HB wrote:

Hi, Lloyd.
The voltage ratios have to be the same, either direction, as they are
physical quantities(turns counts). What doesn't work it the KVA
rating, according to the electrician that installed the transformer to
operate our convection oven for soldering circuit boards. He said to
de-rate the KVA 10%. We have been running a transformer backwards to
get 480 from 208 for about 4 years, now. 24/7.

Paul

True the voltage levels at no load have to be the same. But the
voltage ratios do not have to be 2:1. As Don and Lloyd say, the
smaller transformers are designed with a ratio slightly off of 2:1.
That is so at the rated load, with some voltage reduction because of
losses in the transformer, the voltage ratio is 2:1.

But it reminds me of the difference between an engineer and a
physicist. If a physicist enters a room and sees a naked girl on the
other side of the room, he sighs. Because he knows that he can go
toward the girl until he gets half way there. And he can half the
distance again and again, but doing that will never get him to the
girl.

The engineer just barges in, because he knows he can get close enough.

Dan

Manny

It will be Friday before I can get back with you..more than
likely..Saturday morning. Ive got to be in Anaheim at 7am and start
tearing down a BIG factory. *Ill be down there until its done..cause
they have to be out by the 9th.

If your not in a hurry..Ill do it for you.

Hell..I may have some from this factory. Ive got to clear the entire
100,000 square foot out.

Gunner


I'll be waiting on any leads to come my way. Thanks.

It depends on the "Q" of the transformer. A tight core and winding
can do wonders. Loose windings are fudging and might not be turns true.

Martin

Gunner Asch wrote:
On Tue, 26 May 2009 20:13:15 -0500, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:

David Lesher fired this volley in news:gvi3nb$2i8$1
@reader1.panix.com:

I know of no reason you can't do exactly that, and have done
so at lower power levels.
Ignorance doesn't make it work properly.

Sorry, but you and Gunner are reading off the same page, and it's not
even in the electronics book.

LLoyd


google "using a step down transformer in reverse"

Results...96,800 hits

Shrug, believe what you wish to.
You are still wrong. Shrug.

Gunner

"Lenin called them "useful idiots," those people living in
liberal democracies who by giving moral and material support
to a totalitarian ideology in effect were braiding the rope that
would hang them. Why people who enjoyed freedom and prosperity worked
passionately to destroy both is a fascinating question, one still with us
today. Now the useful idiots can be found in the chorus of appeasement,
reflexive anti-Americanism, and sentimental idealism trying to inhibit
the necessary responses to another freedom-hating ideology, radical Islam"

Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno

Thanks Don I'm almost there.......
Martin

wrote:
On May 27, 5:14 am, KD7HB wrote:

Hi, Lloyd.
The voltage ratios have to be the same, either direction, as they are
physical quantities(turns counts). What doesn't work it the KVA
rating, according to the electrician that installed the transformer to
operate our convection oven for soldering circuit boards. He said to
de-rate the KVA 10%. We have been running a transformer backwards to
get 480 from 208 for about 4 years, now. 24/7.

Paul

True the voltage levels at no load have to be the same. But the
voltage ratios do not have to be 2:1. As Don and Lloyd say, the
smaller transformers are designed with a ratio slightly off of 2:1.
That is so at the rated load, with some voltage reduction because of
losses in the transformer, the voltage ratio is 2:1.

But it reminds me of the difference between an engineer and a
physicist. If a physicist enters a room and sees a naked girl on the
other side of the room, he sighs. Because he knows that he can go
toward the girl until he gets half way there. And he can half the
distance again and again, but doing that will never get him to the
girl.

The engineer just barges in, because he knows he can get close enough.

Dan

On May 26, 3:49*pm, Ignoramus17493 ignoramus17...@NOSPAM.
17493.invalid wrote:
I have one for sale.



i

Ig...

I sent you an email of inquiry but have not received a response. Let
me know.

On 2009-05-28, trg-s338 wrote:
On May 26, 3:49?pm, Ignoramus17493 ignoramus17...@NOSPAM.
17493.invalid wrote:
I have one for sale.



i

Ig...

I sent you an email of inquiry but have not received a response. Let
me know.

Response sent. Sorry. I will test it over the weekend.

i