MR .Engr

[nafis]

why....Wye ? wye connection is consider the most economical for small ?high voltage
transformer and

Delta-delta connection is consider the most economical for large to low voltage
transformer


thanks

 

[quogueelectric]

name the EE who claims this and we will call them.

 

[nafis]

guessing you do not agree with the statement .

 

[jim dungar]

why....Wye ? wye connection is consider the most economical for small ?high voltage
transformer and

Delta-delta connection is consider the most economical for large to low voltage
transformer

Interesting, considering Delta-Wye is probably the most common.

 

[charlie b]

It's not a question of economics. The question of whether the secondary should be a Delta or a Wye is simply a matter of whether you need the neutral connection to serve the intended loads. Offhand, I can't think of a good reason to ever use a WYE on the primary side.

 

[jghrist]

Offhand, I can't think of a good reason to ever use a WYE on the primary side.

See http://www.geindustrial.com/publibrary/checkout/38652.30055.7762.44019/generic/GET-3388B.pdf
Whys of the Wyes

 

[Jraef]

See http://www.geindustrial.com/publibrary/checkout/38652.30055.7762.44019/generic/GET-3388B.pdf
Whys of the Wyes

Great find!

Sometimes I fear that the "new world economy" is going to do away with the ability for manufacturers to publish things like that. Too much emphasis on the quarterly bottom line.

 

[zog]

Those papers from OEM's are getting harder and harder to find, many OEM' sare also pulling operations and maintenence manuals for older equipment off thier websites.

 

[Fulthrotl]

why....Wye ? wye connection is consider the most economical for small ?high voltage
transformer and

Delta-delta connection is consider the most economical for large to low voltage
transformer


thanks

generally speaking, dry type transformers are delta primary.

so, it would be delta primary, and wye secondary.

delta secondaries are used mostly when a public utility want's to
save money on supply transformers.

you can start of with an open delta, centertap one phase,
and end up with 3 phase service using two xfmrs, instead of three.

when and if you need to increase the service capability, you can
add the third xfmr, and have a closed delta service. lot's of utilities
did this during WW2, when materials for xtmr's were at a shortage.


randy

 

[jghrist]

Another reason that most North American utilities use grounded wye - grounded wye transformers with five-legged cores is that ferroresonance is not nearly as likely as with an ungrounded primary winding. Ferroresonance can be a problem when the transformer is served by a significant length of underground cable where one phase can become open either by switching or fusing. See http://www.mikeholt.com/technical.p...erroresonance and Its Effects On Transformers

 

[weressl]

Great find!

Sometimes I fear that the "new world economy" is going to do away with the ability for manufacturers to publish things like that. Too much emphasis on the quarterly bottom line.

Interestingly Jack Walch started that ball running. No they panned offf their MV gears to Powell....

Shees......

 

[peter d]

Another reason that most North American utilities use grounded wye - grounded wye transformers with five-legged cores is that ferroresonance is not nearly as likely as with an ungrounded primary winding. Ferroresonance can be a problem when the transformer is served by a significant length of underground cable where one phase can become open either by switching or fusing. See http://www.mikeholt.com/technical.p...erroresonance and Its Effects On Transformers

Thanks for the link...very fascinating. I learned something new today.