what is the role of impedance in transformer?based on
secondary f.l.current(139 amps) and impedance(4.07) of
415/415v of 100 kva transformer. what is the primary
current?



what is the role of impedance in transformer?based on secondary f.l.current(139 amps) and impedanc..

Answer / ma.amulraaj,b.e. mba.,

It is %impedance Voltage.In Transformer,%impedance Voltage plays significant role .Here 100KVA,11KV /415 V.


Full load current Sec .current= VA / 1.732x V (Sec.Voltage)


=(100x 1000 )/(1.732x415 ) =139 Amps, ok


Full load current Primary .current= VA / 1.732x V (Primary
Voltage)


=(100 x 1000)/(1.732 x 11000)
=5.25 Amps

Here ,the full load secondary current is 139 Amps,the rated secondary voltage is 415 V,we can do Short circuit test by applying secondary voltage 415 V,we cannot get the full load secondary current,due to impedance of Transformer.Then we have to raise the secondary voltage gradually, at particular voltage it delivered the full load secondary current,note down the voltage say 440V.From that voltage we have to find out % impedance.440 /11000 = 4% %Z=4.0 %.As this case %Z=4.07,ie. it is (4.07 x11000)/100 =447.7 V.It means This transformer may delivered a full load current at 447V.


This % Impedance may vary from Transformer to Transformer.

Is This Answer Correct ?    3 Yes 1 No

Post New Answer

More Electrical Engineering Interview Questions

what is the question paper model for section engineer in RRB

0 Answers   RRB,


How to calculate the CFM to TR? What is the Formula

12 Answers   Carrier, Voltas,


what is inter connected dc generator?

0 Answers   Lovely Professional University,


If the output of a 100kva, 415v generator is stepped up to 11kv with a 500kva transformer,can the transformer be Loaded above the source generator loading?

2 Answers  


why single phase induction motors are not self staring ? how can we start the 1-phase Induction motor ?

3 Answers   BDL,






the resistance of wire having length X M is R OHEM if i streched the wire to dubble length what will be the resitance

3 Answers  


how step down and step up voltage is occured in transformer

3 Answers  


What is the difference between eath fault protection & Restricted Earth fault Protection?

2 Answers  


what is difference of electrical and electronics

6 Answers   SSIL,


How is the Depth of Stator Slot being calculated for Synchronous Generator?

2 Answers  


In dc ckt. 24v or 110v, which one is more efficient and why?

0 Answers  


Can clean earth cable be considered as low current cable

0 Answers  


Categories
  • Civil Engineering Interview Questions Civil Engineering (5085)
  • Mechanical Engineering Interview Questions Mechanical Engineering (4451)
  • Electrical Engineering Interview Questions Electrical Engineering (16632)
  • Electronics Communications Interview Questions Electronics Communications (3918)
  • Chemical Engineering Interview Questions Chemical Engineering (1095)
  • Aeronautical Engineering Interview Questions Aeronautical Engineering (239)
  • Bio Engineering Interview Questions Bio Engineering (96)
  • Metallurgy Interview Questions Metallurgy (361)
  • Industrial Engineering Interview Questions Industrial Engineering (259)
  • Instrumentation Interview Questions Instrumentation (3014)
  • Automobile Engineering Interview Questions Automobile Engineering (332)
  • Mechatronics Engineering Interview Questions Mechatronics Engineering (97)
  • Marine Engineering Interview Questions Marine Engineering (124)
  • Power Plant Engineering Interview Questions Power Plant Engineering (172)
  • Textile Engineering Interview Questions Textile Engineering (575)
  • Production Engineering Interview Questions Production Engineering (25)
  • Satellite Systems Engineering Interview Questions Satellite Systems Engineering (106)
  • Engineering AllOther Interview Questions Engineering AllOther (1379)