Download GTU (Gujarat Technological University) BE/BTech (Bachelor of Engineering / Bachelor of Technology) 2019 Summer 8th Sem New 2180901 Testing And Commissioning Of Electrical Equipments Previous Question Paper
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ?VIII(NEW) EXAMINATION ? SUMMER 2019
Subject Code:2180901 Date:17/05/2019
Subject Name:Testing and Commissioning of Electrical Equipments
Time:10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
MARKS
Q.1 (a) List the factor affecting earth resistance. 03
(b) List the methods of slip measurement in induction motor. Briefly
explain slip measurement by rotor frequency.
04
(c) For below listed troubles in power transformer, state its causes and
remedies:
1) Internal short circuit 2) Overheating
3) Rapid deterioration of oil
07
Q.2 (a) State the purpose of the following tests:
Type tests, Routine tests, Special tests, Development tests
03
(b) Before installation of the machine what general checkups needs to
be performed?
04
(c) List various methods of neutral grounding. Explain in detail the
method of solid grounding with its merits and demerits.
07
OR
(c) List various methods for earth resistance measurement. Explain
fall of potential method for measurement of earth resistance.
07
Q.3 (a) What is polarization index? What is its significance? 03
(b) Explain the drying out procedure of power transformer with
necessary graph.
04
(c) State the purpose of high voltage testing of power transformer.
Describe test set up for impulse testing of power transformer.
07
OR
Q.3 (a) Explain the polarity of windings. 03
(b) What are the causes of low value of insulation resistance in the
power transformer? How insulation resistance can be brought to
required level?
04
(c) Draw DY1 & DY11 type transformer connections & state
feasibility of connecting them in parallel with reason.
07
Q.4 (a) Explain the cause of noise produced by the rotating machine. 03
(b) For the following troubles with slip ring induction motor, state its
possible causes:
1) Motor runs slow 2) Motor fails to start
04
(c) Explain the no load test and blocked rotor test of an induction
motor. What data such test provides?
07
OR
Q.4 (a) Enlist different tests to be performed on busbar. 03
(b) Explain any one test to be performed on three phase synchronous
machine to find out its synchronous impedance.
04
(c) What is degree of protection? How it is designated? What is IP
and IC code?
07
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1
Seat No.: ________ Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER ?VIII(NEW) EXAMINATION ? SUMMER 2019
Subject Code:2180901 Date:17/05/2019
Subject Name:Testing and Commissioning of Electrical Equipments
Time:10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full marks.
MARKS
Q.1 (a) List the factor affecting earth resistance. 03
(b) List the methods of slip measurement in induction motor. Briefly
explain slip measurement by rotor frequency.
04
(c) For below listed troubles in power transformer, state its causes and
remedies:
1) Internal short circuit 2) Overheating
3) Rapid deterioration of oil
07
Q.2 (a) State the purpose of the following tests:
Type tests, Routine tests, Special tests, Development tests
03
(b) Before installation of the machine what general checkups needs to
be performed?
04
(c) List various methods of neutral grounding. Explain in detail the
method of solid grounding with its merits and demerits.
07
OR
(c) List various methods for earth resistance measurement. Explain
fall of potential method for measurement of earth resistance.
07
Q.3 (a) What is polarization index? What is its significance? 03
(b) Explain the drying out procedure of power transformer with
necessary graph.
04
(c) State the purpose of high voltage testing of power transformer.
Describe test set up for impulse testing of power transformer.
07
OR
Q.3 (a) Explain the polarity of windings. 03
(b) What are the causes of low value of insulation resistance in the
power transformer? How insulation resistance can be brought to
required level?
04
(c) Draw DY1 & DY11 type transformer connections & state
feasibility of connecting them in parallel with reason.
07
Q.4 (a) Explain the cause of noise produced by the rotating machine. 03
(b) For the following troubles with slip ring induction motor, state its
possible causes:
1) Motor runs slow 2) Motor fails to start
04
(c) Explain the no load test and blocked rotor test of an induction
motor. What data such test provides?
07
OR
Q.4 (a) Enlist different tests to be performed on busbar. 03
(b) Explain any one test to be performed on three phase synchronous
machine to find out its synchronous impedance.
04
(c) What is degree of protection? How it is designated? What is IP
and IC code?
07
2
Q.5
(a)
Define the making and breaking rating of the circuit breaker.
03
(b) Explain mechanical endurance test on circuit breaker. 04
(c) Explain the working of ELCB? What are the different tests
performed on it?
07
OR
Q.5 (a) Discuss the need for gas insulated substation. 03
(b) Discuss different cooling system of rotating electrical machines in
brief.
04
(c) Explain Murray loop test for ground fault location in
underground cable.
07
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This post was last modified on 20 February 2020