Visvesvaraya Technological University (VTU) 2005 B.E Electrical and Electronics Engineering 6th SEM / TESTING AND COMMISSIONING OF ELECTRICAL ELECTRICAL EQUIPMENTS - Question Paper

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Sixth Semester B.E Degree Examination, January/February 2005 Electrical and Electronics Engineering Testing and Commissioning of Electrical Equipment

Tii - Z hrs.]    [Max.Marks : 100

Note: Answer any FIVE full questions.

1.    (a) Explain the procedure of drying out of power transformers.    (1 o Marks)

(b)    Slate the purpose of conducting high voltage test on power transformers. State which high voltage tests are performed on power transformers as type test and routine test.

(5 Marks)

(c)    Explain the safety precautions to be taken while commissioning and maintenance of power transformers.    (5 Marts)

2.    (a) Which factors should be considered while selecting protection scheme for power trans

formers? Stale the various protections provided for power transformers.

(10 Marks)

(b) With neat sketch explain the principle & working of Buchholz relay.    (10 Marks)

3.    (a) Explain the requirements of civil engineering foundation work for medium and large

induction motors.    (10 Marks)

fb) State the various steps in Ihe installation & commissioning of induction motor. (10 Marks)

4.    (a) Explain the open circuit and short-circuit test on a slip ring induction motor. (10 Marks)

(b) Explain the procedure of inspection of an electrical machine prior to its installation.

(10 Marks)

5.    (a) State and explain briefly the types of cooling employed for large turbo generators.(io Marks)

(b) State and explain the procedure of various tests on the synchronous machine and their significance.    (10 Marks)

6.    (a) Explain what care should be taken while installing synchronous machine. (10 Marks)

(b) State the difference between main switch gear and auxiliary switch gear used in power Station.    (10 Marks)

7.    (a) Explain the safety precautions to be taken in maintenance of a circuit breaker. (5 Marks)

(b)    State the factors to be decided in selecting circuit breakers.    (5 Marks)

(c)    Explain the layout of a simple short-circuit testing station and the procedure of conducting

S C. test.    (10 Marks)

8.    Write short notes on the following :    (5x4=20 Marks)

i)    Testing of transformer oil    i

ii)    Polarisation index    :^!t '

iii)    Maintenance & care of ball bearings

iv)    Specification of synchronous machine

Attachment: visvesvaraya-technological-university--vtu--2005-b-e-electrical-and-electronics-engineering-41882-1.jpg

Earning:   Approval pending.