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#127554 - 08/23/01 07:51 PM crazy 3 phasy
sparky Offline
Member

Registered: 10/18/00
Posts: 5545
Ok, We all know 2 X-formers and 3 hots can do an open delta, but.......
Can 3 X-formers and 2 hots be configured into some sort of 3 phase arrangement?

According to one source , this is called a 'scotch-something...'


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#127555 - 08/24/01 05:38 PM Re: crazy 3 phasy
Redsy Offline
Member

Registered: 03/28/01
Posts: 2138
Loc: Bucks County PA
You are referring to a Scott connected configuration, in which a 3 phase primary is connected to two transformers in such a manner that 2 phase power is availableon the secondary. This information is available in McGraw-Hill's "American Electricians Handbook"

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#127556 - 08/28/01 05:58 PM Re: crazy 3 phasy
sparky Offline
Member

Registered: 10/18/00
Posts: 5545
hmm;
i see it in the index, but not in the book, go figure....

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#127557 - 08/28/01 06:33 PM Re: crazy 3 phasy
Redsy Offline
Member

Registered: 03/28/01
Posts: 2138
Loc: Bucks County PA
 Quote:
Originally posted by sparky:
hmm;
i see it in the index, but not in the book, go figure....


Sparky,
What edition do you have? I'm home and my 11th edition discusses this beginning on page 5-55. There is a diagram on page 5-57. When I go in tomorrow, I'll check my other(newer) edition.

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#127558 - 08/28/01 06:54 PM Re: crazy 3 phasy
sparky Offline
Member

Registered: 10/18/00
Posts: 5545
well I have a 13th, the index says it's at 5-92 to 5-94, which is just a lot of stuff about drying X-formers

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#127559 - 08/29/01 04:21 AM Re: crazy 3 phasy
Redsy Offline
Member

Registered: 03/28/01
Posts: 2138
Loc: Bucks County PA
 Quote:
Originally posted by sparky:
well I have a 13th, the index says it's at 5-92 to 5-94, which is just a lot of stuff about drying X-formers

I have the 13th, also.
The index is confusing. It refers to sections, not pages. Look at SECTION 5-92 on PAGE 5.67

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#127560 - 08/29/01 09:58 AM Re: crazy 3 phasy
George Corron Offline
Member

Registered: 05/16/01
Posts: 728
Loc: Lorton, Va USA
Designed to replace the Edison 3 wire DC hook up when swapped over to AC. Unless you work around coal mines (DC equipment runs on AC or batteries) you'll never see one. coal mine info is old, don't know if they still do it that way.

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#127561 - 08/30/01 03:34 AM Re: crazy 3 phasy
sparky Offline
Member

Registered: 10/18/00
Posts: 5545
Look at SECTION 5-92 on PAGE 5.67
Dohh! Homer Simpson....
Ok, so I can't use my own book!

anywho,
there it be, stange animal that it is. Could this be used in reverse? I.E.- get 3 phase 208V out of 2--4160V high legs?
that was the description I got from my 'source'

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#127562 - 08/30/01 05:51 AM Re: crazy 3 phasy
JBD Offline
Member

Registered: 07/12/01
Posts: 599
Loc: WI, USA
According to my engineering books the Scott connection is normally used for 2-phase to 3-phase conversion. If used in a 3 to 2 conversion the transformer output needs to be reduced to 86.6% of the combined single-phase ratings.

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#127563 - 08/30/01 05:57 PM Re: crazy 3 phasy
sparky Offline
Member

Registered: 10/18/00
Posts: 5545
JBD,
can you elaborate?
the particular situation here was a linesman stating that 2 out of 3 phases were available at a job, and 3 ph was created via this 'Scott' configuration.

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