electrical

To the original equipment manufacturer's instructions.

Dear shiva,

Your question is in complete or you could not explain what really you want to know. There is is no harm in explaining a question or to state clearly what you really want to know.

In the present question the star Delta connections are made as per the type of transformer. For example a delta / star transformer will have delta connection in primary and star connection in secondary.

If you want to know on what basis you choose a star/ delta , delta /star ,star/ star

delta /delta. and so on . Then it is chosen depending on the utility. For example

1. If you have a 3 phase 3 wire 11 kV line and if your requirement of power is 3 phase 440 V and 230V single phase then you use a 3 phase 11/0.44 kV delta/ star transformer.

2. For distribution system of 33kV and 11kkV system both three wire, then you use a 33/11 kV delta/ delta transformer.

4. If you have more doubts the ask in detail.

hi abraham.thanks for u r kind information.thank u very much.

my 1st question is"what is the major change and the advantage of using the delta/delta and star/delta in practical purposes.I mean using at consumer side only.I mean what are the changes in line voltage and phase voltage angles and what is the advantage"?

my 2 question is"Is there any specific direction and angle to place brushes in dc motor or we can place anywhere"?If there "at what axis and direction of armature we have to place the brushes in dc motor for the dc motor to run safely and efficienty"?

please tell about this.pls..thnx for u r reply

Dear Guest,

Sorry I am not able to understand your question .

" change and advantage" in what ?

As explained earlier a transformer is required to be used when you want to step up or step down the voltage with neutral point or with out neutral point or as an isolation transformer with same turns ratio or different turns ratio as per requirement . Always it will depend on the nature and type of load. The transformers are specified with the type of connection and vector group. ( Example DY11 )

Please read the links below . You can get better idea and clear your doubts.

http://en.wikipedia.org/wiki/Vector_group

http://en.wikipedia.org/wiki/Transformer

ok my friend,thnx for u r guidance.let hat keep aside that questiob.

my 2 dought id "where to use a star connection or delta connectin in a motor "?and what are the conductor size that is to be used in star and delya.in the windings and the inconming terminals

my dear frnd abraham.

you havent seen my question.

u might be busy,sorry for the disturbance.

if ypu free pls ans this question.

"my question is"where to use star connected motor and where delta connection.

and while desighning,wat is the condr size inside and outside motors in practically?"that is condr size that is to prescribe while installation of motor?