Will it be OK to connect a 5MVA 33/6.6kV Ynd11 Transformer
to a Star connected Motor. Or on other words connecting a
Delta to a Star.

I have another 30MVA 33/11 Dyn11 and would it be practical
to convert it to Dd0 consequently converting the Voltage
Ratio to 33/6.35kV Dd0.



Will it be OK to connect a 5MVA 33/6.6kV Ynd11 Transformer to a Star connected Motor. Or on other w..

Answer / a.p.nanjappa

yes. what is the capacity of motor?
In your case , grid voltage is 33kv, Yn connected.Hence
power transformer has neutral connection brought
out.Neutral CT is installed to detect the ground faults.
secondary of 5MVA tranformer is 6.6kv,
This is Feeder bus voltage.6.6kv Feeder bus feeds Motor (
star connected). and Feeder bus is not interconnected to
another source. It is independent.This 6.6kv rotates at 30
lagging to primary3kv system.
Motor must be use inverse & instantaneous time
overcurrent and earth fault ( CDG61+cdg12) or equivalent
manufacturer protection
we use delt to star as weelas star 6.6motor.
No problems experienced.
In the othercase to change a 30MVA,33/6.35KV IS
REDESIGN/MANUFATURING. iT IS EXPENSIVE.No use at all and
advantage. You should change 6.6kv sw.gr also.

Is This Answer Correct ?    1 Yes 0 No

Post New Answer

More Electrical Engineering Interview Questions

what is magnetizing current test in power transformer

0 Answers   ABB,


Write the difference between OCB,VCB ?

3 Answers   Svam Power,


what are pilot cells

0 Answers   KSEB,


What is ignition module of a CAT Gas Genset G-3508 Engine, Alternator SR4B Series. HOw its checked for correct functioning.Is it repiarable or replacable?

0 Answers  


What is the relation of current with torque when motor started in Y-connection???

4 Answers  






why onlyseries motors are used as universal motors? why not shunt?

4 Answers   TCS,


one cable insulation resistance 200 mega ohm. how find 250 meter cable resistance.

2 Answers   NTPC,


What is the approximate percentage of Si content in transformer core(CRGO-Cold Rolled Grain Oriented)? Why it is kept so low?

1 Answers  


What is the difference between Welding Transformer and Normal Transformer?.

2 Answers   DAE,


I Have 3 Phase 10 KW AC Alternator i found one phase weak, so what will be the reason & what action shouls i take to rectify the same.

0 Answers   Vadilal,


sir, what is the importance of Fault MVA. how to calculate fault mva of 33kv substation connected by 6.5 km line(single circuit with equal spacing) with 110/11kv transformer in 110kv susbstation.the fault mva on 11 kv bus in 110kv susbstation is 208mva.

0 Answers  


if voltage is not builed up in small generator what will be the reason?

7 Answers   century,


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)