Visvesvaraya Technological University (VTU) 2006 B.E Electrical and Electronics Engineering 6th SEM TESTING AND COMMISSIONING OF ELECTRICAL EQUIPMENTS - Question Paper
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Sixth Semester B.E. Degree Examination, July 2006 Electrical and Electroni&Engineering Testing and Commissioning of Electrical Equipment Time: 3 hrs.] [Max. Marks: 100
Note: 1. Answer any FIVE full questions.
1 a. Enumerate the standard specifications of a transformer. (04 Marks)
b. Explain the procedure for drying of windings of transformer with and without Oil. (10 Marks)
c. Explain with neat figure the working of a Buchholtz relay. (06 Marks)
2 a. Describe the method of impulse testing on transformers. (08 Marks)
b. What are the methods of indirect testing of transformers to find the efficiency? Explain. (08 Marks)
c. What are the mechanical forces that develop during the working of a transformer? (04 Marks)
3 a. Give the details of foundation used for induction motors. (05 Marks)
b. Explain how the shaft alignment is carried out in induction motors. (07 Marks)
c. Enumerate the commissioning tests carried on induction motors. (08 Marks)
4 a. What are the vibration measurements methods used in induction motors?
(06 Marks)
b. What is insulation resistance? Enumerate the factors affecting the insulation resistance measurements. (06 Marks)
c. Explain the high voltage test conducted on induction motors. (08 Marks)
5 a. Enumerate the various steps of installation of a synchronous machine.
(06 Marks)
b. Give the details of excitation system used in synchronous machine. (04 Marks)
c. Define the following:
i) Primary coolant ii) Secondary coolant iii) Heat exchanger
iv) Open circuit cooling v) Closed circuit cooling. (10 Marks)
6 a. Define short circuit ratio (SCR) of a synchronous machine and explain how it
is obtained. (06 Marks)
b. Explain the sudden short circuit test conducted on synchronous generator.
(10 Marks)
c. Explain the vibration test carried on a synchronous machine. (04 Marks)
7 a. Explain the high voltage test carried on circuit breakers at site. (06 Marks)
b. What are the steps involved in installation of circuit breakers? (04 Marks)
c. What are the maintenance operations required for a SFe circuit breaker?
(10 Marks)
8 Write short notes on the following:
a. Testing of transformer oil.
b. Temperature raise test on induction motors.
c. Drying out of synchronous machine.
d. Selection of circuit breakers. (20 Marks)
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