Answer / k.prakashchandra

To dehydrate the windings.In view of high level of water /
moisture content in insulation ,it is recommended to
thoroughly dehydrate the windings by subjecting to vacuum
heating and drying after untanking the oil.Care should be
taken to see that the tank would not buckle due to the vacuum.

Answer / santosh

vaccum creating to check any leakage point.

Answer / byd

Generally Hermetic Onan transnformer vaccume before oil
filteration and after oil filling,, because if there is
any air inside of transformer tank and oil then we
apply anergy after there will be short circuit and
insilation resistances will be min, and IEC 60076-1 High
voltage test, if transformer is 33kv, you should apply
mono phase to HV winding as 70kv for 1 minute,, if there
is any short circuit it means oil didnt vaccume ,, or
there is some insilation wrong ,, i am sorry my english
is not good

When we have earthing mesh or underground earthing network in industrial plants, weather we have NT-S or NT-C-S kind of earthing system, so eventually weather we must use 4 or 5 wire in 400 volt level (For example 3×150+70 mm2 or 5×150 mm2) in this connection I would like to know exactly the paragraph of IEC or IEEE number

0 Answers   TATA,

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Can the field winding in synchronous machines be placed on stator?What is the limitation of such arrangement?

2 Answers  

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Short circuit voltage of a transformer mainly depend on A ohmic resistance of primary B ohmic resistance of secondary C magnitude of leakage flux D cross sectional area of core

1 Answers  

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which one has maximum efficiency autotransformer or transformer?? and why??

2 Answers  

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what will happen if u run induction motor beyond its rated speed

13 Answers   Adani, BARC, Bescom,

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Without seeing the nameplate descriptions of a rotating machine,Is it possible to say which one is a motor and which one is a generator? How would you certain this?

3 Answers  

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what is 33 /11kv transformer bdv

8 Answers   NMDC, TPPL,

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Hi,iam a diploma in electrical engineering.rtd from indian air force in apr 2007.prsently working in reliance next link as a network maintenance engineer since 2007,can i get a job in motherson sumi.

0 Answers   Motherson, Motherson Molds and Diecasting Ltd.,

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what is the meaning of rms value

24 Answers   Fitter, IOCL, OCL,

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The capacity of the transformer is 20/25 MVA, Ratio is 132/11 KV, Vactor group YNyno. and impedance is 10.07%. As per the calculation the secondary current is 1312.2Amps. The maximum fault current the transformer should sustain is 13.030KA. How many times the transformer should sustain the maximum short circuit current of 13.030KA over a period up 1 Year. The transformer is repaired one & 10 Years old.

1 Answers  

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What is the application of Nitrogen Injection system in Transformer Protection?

1 Answers   HPL,

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I meggared my 2c*70 sq mm AL AR XLPE cable. its one end show 50 M ohm . is my cable is safe for laying. I have only one phase and neutral.

0 Answers  

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