ASSIGNMENT - rcti.cteguj.in · SWITCH GEAR & PROTECTION CHAPTER-1 ... Reset value c) Stability d) ... Obtain the equation produced in induction disc relay. Q4. What is mean by IDMT?

R. C. TECHNICAL INSTITUTE, AHMEDABAD ELECTRICAL ENGG. DEPARTMENT

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ASSIGNMENT SWITCH GEAR & PROTECTION

CHAPTER-1

ELEMENTS OF PROTECTION

[A] Explain following questions. (1 or 2 Marks Question)

Q1. Define Primary Protection.

Q2. Define Backup Protection.

Q3. Define fault.

Q4. Define Switchgear protection.

Q5. Define circuit breaker.

Q6. What is relay?

Q7. What are the different types of Backup protection?

Q8. Name the elements of protecting system.

[B] Explain following questions. (3 or 4 marks question)

Q1. Draw the block diagram of protective system & state function of each block.

Q2. Draw the single line diagram of power supply system & explain it.

Q3. Give the difference between backup protection system & primary protective system.

Q4. Give the difference between Normal condition & Abnormal Condition.


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[C] Explain following questions. (5 or 7 marks question)

Q1. What is backup Protection? Explain the necessity of backup protection. What are its

different types?

Q2. State reasons of occurrence of faults in power system.

Q3. State the essential characteristics of the protective relaying system.

Q4. State the Abnormalities occurring in power supply system & describe it.

Q5. What are the consequences of fault?


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PROTECTIVE RELAYS


Q1. Define the following terms:-

a) Pickup value

b) Reset value

c) Stability

d) Under reach

e) Dropout

f) Over reach

g) Rated burden

h) Error

i) Operating time

Q2. Explain the following terms:-

a) Auxiliary relay

b) IDMT relay

c) TMS

d) PSM

e) Energizing Quantity

f) Characteristic Quantity

g) Pickup Current

h) Flag

i) Continuous Rating

j) Blocking

Q3. Define the following terms related with relay:-

a) Change over Contacts

b) Break Contacts

c) Hand Resetting Contacts

d) Momentary or Fleeting Contacts

e) Making Capacity

f) Breaking Capacity

g) Current Carrying Capacity


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Q1. Define the following Relays:-

a) Directional Relay

b) Instantaneous Relay

c) Differential Relay

d) Gas Operated Relay

e) Static Relay

f) Current Relay

g) Plug in Relay

h) Electromagnetic Relay

i) Inverse Definite Minimum Time Lag Relay


Q1. Give the differences between the followings

a) Protective & Auxiliary relay

b) Current Transformer & Potential Transformer

Q2. The current setting of an over current relay is 125%. If the fault current is 2400A, find the

PSM of the relay, if the ratio of CT is 400/5.

Q3. Explain the working of thermal relay with the help of diagram.

Q4. Classify protective relays on the basis of operating principle.

Q5. What are the general requirements to be satisfied by the protective relays?

Q6. Why maintenance is required in protective relays.

Q7. Explain Microprocessor based inverse time over current relay with the help of diagram.


Q1. Explain the working of Electromagnetic Attraction type relay with the help of diagram.

Q2. Explain the construction, Working & Applications of balance beam impedance type relay.

Q3. Obtain the equation produced in induction disc relay.

Q4. What is mean by IDMT? Draw the characteristics of such relay & state its application.

Q5. Explain the working of bucchloz relay with the help of neat diagram.

Q6. Explain the construction & working of Permanent Magnet Moving Coil relay.


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Q7. Write down the advantages & disadvantages of Static relay.

Q8. Draw the block diagram of instantaneous Static over current relay & explain it.

Q9. Give the difference among directional, directional over current relay & reverse power relay.

Q10. What is Directional relay? Explain it with the help of neat diagram.

Q11. Explain the Construction & working of Directional Power relay or reverse power relay.

Q12. Explain the working of different parts of induction disc type relay, Draw its sketch.

Q13. What are the different types of tests need to be performed on relay.


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CIRCUIT INTERRUPTING DEVICES

[A] Explain following question (1 or 2 Marks Question)

Q1. Define the following terms with reference to the fuse:-

a) Prospective Current

b) Fusing factor

c) Current Rating

d) Arcing time

e) Cut off current

f) Pre arching time

Q2. Define the following terms with reference to circuit Breaker:-

a) Symmetrical Breaking Capacity

b) Breaking time

c) Making Capacity

d) Short time rating


a) Recovery Voltage

b) Active Recovery Voltage

c) Re Striking Voltage

d) Rate of Rise of recovery voltage

e) Total breaking time


a) Fuse

b) Circuit Breaker

c) Isolator

d) Earth switch

[B] Explain following question (3 or 4 marks question)

Q1. Explain the difference among Isolator, Switch & Circuit Breaker.

Q2. Give the difference between:-

a) Fuse & Circuit Breaker

b) Switch & Circuit Breaker

c) Isolator & Switch


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d) Isolator & Circuit breaker

Q3. State the basic elements of Circuit breaker & explain them.

Q4. Describe the construction & working of Drop out fuse.

Q5. State the advantages & disadvantages of HRC fuse.

Q6. Explain the use of Isolator, Circuit Breaker & Earthing Switch in power system.

Q7. Give the classification of Circuit breaker.

Q8. Explain Plain Explosion pot.

Q9. Explain the Arching Phenomenon. How arc is produced and maintained.

Q10. What are the methods for extinction of arc?


1. Explain the construction of HRC fuse & state its advantages & disadvantages.

2. Explain the terms recovery voltage & restriking voltage with reference to the circuit

breaker.

3. State the basic elements & working principle of CB & explain them.

4. Explain the arcing phenomenon. How the arc is produced & maintained. & also explain

the methods for arc extinction.

5. Draw the neat sketch of minimum oil content CB & explain its working only.

6. Compare bulk oil & minimum oil content CB on the basis of advantages, disadvantages

& application.

7. Draw the sketch of the air blast CB & explain its construction & working.

8. Explain working principle, construction, working & advantages of vaccum CB.

9. Explain the working of SF6 CB with diagram. State the merits & demerits of SF6 circuit

breaker.

10. Classify the oil CB. Differentiate bulk oil & minimum oil circuit breaker.

11. Explain the plain break oil CB with the help of diagram


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OVER VOLTAGE PROTECTION


1. Define the term over voltage.

2. What is surge absorber?

3. Define impulse ratio


1. What are the effects of over voltage?

2. State the type of lightning arrestor.

3. Write the short notes on the following.

a. Lightning arrestor

b. Insulation co ordination

c. Ferranti surge absorber


Q1.State the external and internal causes of over voltage. Explain its ill effect in the power

system.

Q2. Explain the construction and working of valve type arrestor.

Q3. Explain the construction & working of electromagnetic type arrestor.

Q4.Explain the construction and working of protector tube, also write its advantages and

disadvantages.

Q5.Write a short note on surge absorber.

Q6.Explain working principle, construction, working & advantages of Thyrite lightning arrestor.

Q7.Explain the principle of insulation co ordination & explain its use.


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ASSIGNMENT

Installation , Commissioning and Maintenance (Code:3360902)

UNIT – I Installation of Electrical Equipment


1) State points to be considered before unloading the equipment.

2) List two lifting devices for loading and unloading of heavy equipment.

3) What is the difference between the chain pulley block and powered chain

pulley block on the basis of operation?

4) State safety precautions to be taken while unloading heavy equipment.

5) List / Enlist tools ( instrument) necessary for Installation.

6) State points to be considered while installing transformer.

[B] Explain following questions. ( 3 or 4 marks question)

1) State the differences between the foundations for Static and Rotating Machines.

2) Give factors to be considered in designing the foundation of electrical machines.

3) State the ill effects of misalignment of shafts of the machines. 4) Explain installation of induction motor. 5) Explain installation of transformer. 6) Explain how the installation of switchgear is done. 7) Explain the procedure of Inspection of an Electrical machine prior to its

Installation. 10)Explain tools / Instruments required for Installation.

11)Explain the points to be taken into consideration while preparing the foundation for Electrical Equipment.


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[C] Explain following questions. (7 marks question)

1) Explain the standard procedure for installation of Transformer and write the

differences in foundation of transformer in compare to Induction motor.

2) State the main points for installation of electrical wiring.

3) Explain installation procedure of domestic appliances.


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UNIT – II Commissioning and Testing


1) Give name of mechanical tests to be performed on electrical equipment

after installation and before starting for the first time.

2) State two electrical tests to be performed on electrical equipment before

commissioning.

3) State the methods of checking phase sequence in three phase a.c. system.

4) Give causes of loosening of coils in transformer.

5) State the problems that may arise if the load is applied suddenly on

alternator.

6) Write causes of deterioration of insulating oil.

7) List the methods of purifying insulating oil.

8) List the methods of drying winding of electrical equipment.

9) Give name of instruments for measurement of insulation resistance.


1) Explain procedure for commissioning of 3 phase induction motor. 2) List commissioning tests on power transformers. 3) Explain procedure for commissioning of switchgear. 4) Give properties of transformer oil as per IS.

5) Explain sampling and testing of Transformer oil. 6) State the method of filtering the insulating oil and explain one method

in detail. 7) What is Polarization Index ? What is its significance ? How it is measured ?

8) What is DRYING? When drying is needed? Write down Drying out

procedure of Transformer winding. 9) Explain measurement of insulation resistance.

10) Explain safety rules and regulations to be observed during commissioning

of electrical equipments/machines.

11) State and explain Electrical Tests to be performed before commissioning the electrical equipments/machines.

12) Explain mechanical tests to be performed before commissioning the electrical equipment.


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1) Explain procedure for commissioning of 3 phase induction motor.

2) Explain procedure for commissioning of switchgear.

3) Make a list of standard tests performed on Insulating Oil and explain any

two from it.

4) Explain dielectric strength test for insulating oil.

5) Explain the importance of Insulation Resistance Measurement Test and list

out general Electrical and Mechanical test to be performed before

commissioning of electrical equipment.

6) Classify insulation on the basis of maximum working temperature and

explain in brief the methods of drying of insulation.


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Unit – III Maintenance of Electrical Equipment

[A] Explain following question (1 or 2 Marks Question)

1) Define preventive maintenance.

2) State two advantages of preventive maintenance.

3) State the difference between overhaul and scheduled maintenance.

4) State factors to be considered while preparing the maintenance schedule.

5) State the inspection carried out annually for the transformer of capacity less

than 1000 KVA.

[B] Explain following question (5 or 7 marks question)

1) Define Preventive maintenance and explain advantages of preventive maintenance.

2) Explain activities performed during preventive maintenance.

3) Compare preventive maintenance and breakdown maintenance. 4) Give maintenance schedule of transformer having capacity below 1000

KVA. 5) Give maintenance schedule of overhead transmission line. 6) Give the maintenance schedule of induction motor.

7) Give maintenance schedule of circuit breaker after the fault is cleared.

Give maintenance schedule of underground cables


1) Explain the importance of preventive maintenance and prepare maintenance

schedule of Overhead line.

2) List the advantage of preventive maintenance and prepare maintenance

schedule of circuit breaker and cable.

3) Explain the maintenance procedure for Domestic appliances.

.


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UNIT – IV Trouble Shooting [A] Explain following questions. (1 or 2 Marks Question)

1) List the devices used for the protection of electrical equipment.

2) State external causes of fault in electrical equipments.

3) Write names of any four instruments for trouble shooting of electrical

equipments.

4) State use of following devices.

i) Growler , ii) Dial gauge

5) Write four possible reasons for heavy noise from three phase induction

motor.

6) State possible causes when DC motor runs slowly.

7) Give possible causes when DC generator does not build up Voltage.

8) Single phase induction motor runs slowly , state possible causes.

9) Ceiling fan does not start when switched on but is runs when blades are

pushed in one direction , state the cause.

10)State the function of choke in fluorescent tube light.


1) Define Trouble shooting. Explain the method of preparing trouble shooting chart.

2) State causes of fault occurring in electrical appliances. 3) Write the mechanical , electrical and magnetic faults occurring in electrical

equipments. 4) Explain trouble shooting chart for D.C. motor.

5) Explain trouble shooting chart for transformer.

6) Explain trouble shooting chart for 3 phase squirrel cage induction motor.

7) State the reasons for the following troubles.

a) Single phase induction motor does not start. b) Sparking occurs at the brushes of d.c. motor.

c) Three phase induction motor does not gather the speed.

d) Motor takes much time to obtain full speed.

e) Motor vibrates after starting.

f) Synchronous motor falls out of synchronism.

8) Explain use of growler in trouble shooting. 9) Explain the mechanical troubles in electrical equipments.


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10) State the probable faults and their reasons for the following electrical equipments.

a) Domestic flour mill, b) Electric Iron, c) Mixer grinder,

d) Washing machine. e) Microwave oven.


1) Explain all the common faults in domestic appliances.

2) Explain the need of troubleshooting chart with their advantage and write the

procedure to preparing troubleshooting chart. 3) Prepare the troubleshooting chart for three phase squirrel cage Induction

Motor and Single phase Induction Motor. 4) Explain trouble shouting chart for transformer.


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UNIT – V Earthing [A] Explain following questions. (1 or 2 Marks Question)

1) What is the purpose of system earthing ?

2) Write names of different types of earth electrodes.

3) List the different types of earthing.

4) Give the values of maximum permissible earth resistance for domestic

installation and small substation.

5) List the methods of measuring earth resistance.


1) List methods of earthing and explain any one method.

2) Give advantage of neutral earthing of generator in power station.

3) Give comparison between equipment earthing and system grounding.

4) Explain the methods of reducing earth resistance. 5) List methods of measuring earth resistance and explain any two method. 6) Explain the method of earthing in sandy bed with advantage and

disadvantage. 7) Explain how earthing of industrial installation is made. 8) Explain earthing of domestic fitting & appliances.

9) Explain earthing of substation and generating station.

10)Explain the earthing of overhead line.


1) Explain necessity of earthing, Compare system earthing with Equipment

earthing and list type of earth electrode used for earthing.

2) Explain the Pipe earthing or Plate earthing and how to measure the earth

resistance. 3) Give advantage of neutral earthing of generator in power station.


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UNIT – VI Electrical accidents and safety


1) State four causes of accidents.

2) State factors contributing the severity of electric shock.

3) List safety devices for worker.

4) Sate fixed installation type fire extinguisher.

5) State portable type fire extinguisher.


1) State the causes of electrical accident and explain one cause in details.

2) State and explain factors controlling the severity of electric shock. 3) Explain the steps to be taken when a person comes in contact with live part. 4) List electrical safety devices. 5) State safety measures to be considered while doing electric work. 6) State the consequence of electrical accident. Write any four Indian

Electricity rules regarding electrical safety. 7) Explain “Permit-to-Work” system. 8) State the fire extinguishers and state their use in locations in different

situations. 9) State the safety rules to be followed while carrying out maintenance of

domestic electrical appliances.


1) Explain common causes and effects of electrical accidents

2) Explain the factors controlling severity of electric shock.

3) Write short note on permit to work.


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ELECTRIFICATION OF BUILDING COMPLEXES

(Code: 3360908)

Unit 1– Elements of Electrification

[A] Explain following questions. (1/2 Marks Question)

1 List only the name of the different types of electrical installations 2 List only the name of outdoor electrical installations 3 Draw the graphical symbol for underground cable and flexible cable. 4 Define: Electrical circuit, Earth leakage current 5 Explain the following terms: Utilization factor, Maintenance factor, Depreciation factor. 6 What should be the size of conductor for final lighting circuit.? 7 Define : Rising main. And give the main drawback of rising main supply system/ 8 Which types of tests to be perform for new wiring installation ? 9 Explain the term stroboscopic effect. 10 On which factor the utilization factor of lamp depend?

[B] Explain following questions. ( 3/4 marks question)

1 What are the different ways for diversifying the electrical installation? Explain them in

detail. 2 Write the procedure of testing of insulation resistance between wiring and earth by suitable

diagram. 3 Describe the method of testing of single switches. 4 Describe the method of testing of earth continuity. 5 Describe the procedure for measurement of earth resistance. 6 Explain the factors to be considered for economical illumination design. 7 List the requirement of illumination in residential building. 8 Draw the diagram of three phase four wire distribution by using busbar. 9 Draw the supply wiring diagram of building by tree system.


1 What are the different ways for looping in wiring system? Explain them in detail. 2 Classify the electrical wiring installation and explain them in detail. 3 Classify the outdoor wiring installation and explain in detail. 4 Three light points are controlled by switches which are placed at different locations. Draw

the (1) Schematic diagram (2) Wiring diagram in looping in system. 5 One light point are controlled by any of three switch placed at different locations. Draw

the schematic and wiring diagram using looping in system.


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6 Draw the neat sketch of three phase four wire distribution for single phase and three phase

loads having a common main fuse. 7 Draw the neat sketch of three phase four wire distribution for single and three phase loads

with separate distribution boards.


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Unit – II Electrification of Multistoried Buildings

[A] Explain following questions. (2 Marks Question)

1 What are the different types of wiring systems for electrical installations? 2 What are the advantages of insulated conduit as compared to steel conduit?

3 Write the full form of: TRS , CTS , DB , MDB , RCD , MCB ,DPIC, TPNIC , CPC,

XLPVC , HRC fuse. 4 What should be limitation of voltage drop in different parts of wiring system of a large

building? 5 Explain : Main raising distribution. 6 What is splitter unit? 7 How the cable connection is done from one house to another house for a given distance? 8 What is the limitation of load and light and fan points for individual sub circuit? 9 Which are the settings to be done for main board and sub distribution board for the

protection by RCD.? 10 State the features of distribution system. 11 What are the different types of distribution board?

[B] Explain following questions. (3/4 marks question)

1 Define : Sub circuit. Explain light and power circuit. 2 Which are the factors affecting the size of the conductor? 3 How estimation of material requirement is done for a given residential plan? 4 How estimation of labour cost is done for a given residential plan? 5 Draw the single line diagram of distribution system for 4 outgoing circuit. 6 Draw the single line diagram of a ring main feeding six distribution board. 7 Find the number of sub circuit for the given residential installation as per given load.

Light point=3

Fan point=2

Three point socket(5A) =2

Three point socket (15A) = 2

[C]

Explain following questions. (7 marks question)

1 Prepare a inspection report for MV installation of consumer. 2 What are the factors to be considered while estimating internal electrification for a given

plan? 3 Explain the estimating and costing procedure in steps for a given plan. 4 Draw the single line diagram of electrical distribution for house wiring by using MDB

and sub MDB. 5 Classify the different types of wiring for electrical installation. Explain in detail.


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6 For the given multistoried building the electrical installation are as follows :

(1) Total no. of point

(2) Total load

(3) Total no. of sub circuit.

Here ,

No. of tube light = 20

No of Fan = 18

3 pin socket (5A) = 18

3 pin socket (15A) = 03

7 The maximum current carrying capacity of cable is 50Amp and the length is 500m. The

supply voltage drop is maximum 5%. If the supply voltage is 400 D.C. and 400 A.C.

Then find the size of the cable. 8 The plan for residential flat is given in the figure. The position of electrical Fan, Light,

Distribution board and switch board are shown. Find the,

(1) No. of sub circuit

(2) Length of conduit

(3) Length of wire

(4) Total cost estimation for electrical installation.


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Unit – III Electrification of Complex and Public Buildings


1 Define Cut out. 2 What is diversity factor for air-conditioning installation and lift load? 3 List the different types of loads for recreation/assembly building. 4 How many sub circuits are provided for installation of assembly building? 5 List the different electrical installations in the multistoried buildings. 6 Write the full form of the EPABX and MOEFA. 7 Classify different types of commercial building according to their group.


1 Draw the wiring diagram of a distribution system for residential building with separate

light/fan and power circuit. 2 Draw the layout of three phase four wire distribution for single and three phase loads with

separate sub distribution boards. 3 Draw a schematic layout of a substation and low voltage switchgear. 4 Which are the factors to be considered during design of electrical installations in

commercial buildings? 5 Explain the basic requirement of building substation for commercial building. 6 Which are the factors to be considered while designing branch circuit for assembly

building? 7 List only the different types of electrical installation in hotels. 8 Which are the building services to be included for electrical installation in hotels? 9 What are the functions of electrical estimators?

10 Write the steps for estimating commercial building project.


1 Explain the special requirements for electrical installation in multistoried buildings.


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Unit – IV Distribution System for Multistoried Buildings


1 How many lightening arresters are installed for protection of pole mounted transformer? 2 How many earthing pits are provided for pole mounted transformer? 3 What is the function of three earthing pit for pole mounted transformer? 4 How many wires is used for single and three phase service connection? 5 Specify the size of copper conductor for service connection having load of 1 kW? 6 Describe the function of filler plates? 7 Write the configuration of panel board. 8 Describe the meaning of ‘High Leg’? 9 Give the reason: Secondary of CT wires should be kept as short as possible. 10 Which type of energy meter is used for load above 60 A? 11 Write the full form of AAC and ACSR. 12 List the methods of cable laying.


1 Define service line. Explain any one method of service connection. 2 How service connection is done for low roof building? 3 Explain the method of service connection by underground cable connection. 4 Draw the layout of substation and low voltage switch board. 5 List the components of 11kv/415 V pole mounted substation. 6 Draw the line diagram of indoor substation. 7 Which type of enclosure is used for panel board? 8 Explain any one configuration of panel board. 9 Explain the split bus protection for distribution panel.

10 List the method of panel board power supply and explain any one of it. 11 Write the meter classification and Explain factors affecting measurements. 12 Explain any one method of cable laying.


1 Explain the single phase digital energy meter. 2 Explain the method of cable lying in trench.


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R.C. Technical Institute

Assignment (Electrical Dept)

Subject: - Maintenance of Transformer and Circuit Breaker.

Subject Code: - 3360907

Chapter: - 1 Preventive Maintenance.

Que:- 1 Answer the following Questions (1 or 2 Marks)

1) Write any two advantages of maintenance schedule?

2) List the major activities to be done during Preventive Maintenance?

3) Write any two advantages of Preventive Maintenance?

4) Define corrective Breakdown Maintenance.

5) What is Preventive Maintenance?

6) List out various types of maintenances.

7) List the various factors to be considered while preparing maintenance schedule.

8) What are the different types of maintenance?

9) Write the advantages of Preventive Maintenance.

10) Write the disadvantages of Preventive Maintenance.

11) List the major activities to be done during Predictive Maintenance

12) What is main purpose of vibration analysis?

13) Which are the activities to be included during overhauling of electrical equipments?


1) List out function of Preventive Maintenance Department.

2) Explain activities performed during Breakdown Maintenance.

3) Write the advantages of Maintenance schedule.

4) Write the advantages and disadvantages of Preventive Maintenance.

5) What is predictive maintenance & list out advantages and disadvantages?

6) What are the predictive techniques?

Que:- 3 Answer the following Questions (7 Marks)

1) Explain Different factors to be considered while preparing maintenance schedule.

2) List the different activities performed during Preventive Maintenance.


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Chapter: - 2 Maintenance of Transformer


1) What is function of Pressure Relay?

2) Which are the factors affecting the life of Transformer?

3) What are the different types of winding used in the Transformer?

4) Write the full forms of;

BDV, PI, CTC.

5) What is Marshalling Kiosk?

6) What is Importance of flash point of Insulating Oil?

7) Define: Breakdown voltage of insulating Oil.

8) Write any two reasons for failure of Transformer Core?

9) Write two Techniques for reduction of noise in the Transformer?

10) Megger indicates ________ reading during shorting of its terminals.

11) Megger indicates ________ reading during its terminals are kept Open.

12) What is function of Gas Operated Relay?

13) Write three Characteristics of Transformer insulating Oil?

14) What should be minimum value of earth resistance in the Two-Winding Transformer?

15) Which are the accessories used in the Distribution Transformer.

16) What is function of conservator in the transformer?

17) On which parameter the operation of the over fluxing relay depends?

18) What are the possible check points during routine daily inspection of the power transformer?

19) What is effect of Oxygen on the insulating oil of the transformer?

20) Which are the factors affecting the life of transformer?

21) What are the different types of factors affecting winding of transformer?

22) How the regeneration of silicon gel of breather is done?

23) What are the possible check points during inspection of silicon gel breather and bushings?

24) What is effect of high/low viscosity in the transformer oil?

25) Why one minute megger reading always higher than the initial megger reading?

26) What are the reasons for rapid deteriotion of transformer insulating oil?

27) What is the information’s to be obtained from measuring earth resistance of the transformer

winding?


1) Explain the significance of Maintenance of a Transformer.

2) Explain Buchholz Relay with Neat Diagram.

3) List out important steps for maintenance of power Transformer during Annual inspection.

4) Explain Characteristics of Transformer Oil.

5) Explain cause of Troubles and failures of cores of Transformer.


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6) Explain the Transformer Oil filteration process by Streamline Purifier Plant.

7) Explain the effect of Following on the life of power Transformer;

a. Operating Temperature

b. Effect of Varnish

8) Which are the tests to be performed on Transformer Oil?

9) Distinguish major and minor repair work in the transformer.

10) Explain the following maintenance schedule (I) Attended (II) Unattended

11) State the importance step in the maintenance schedule of power transformer on

(i) Daily checks

(ii) Monthly checks

(iii) Yearly checks

12) State four reasons for failure of core of the power transformer.

13) Explain the effects of following on the life of transformer:

(i) Moisture

(ii) Varnish

(iii) Slackness of winding.

14) Explain the maintenance procedure of following in the power transformer:

(i) Buchholz relay

(ii) Breather

15) What are the different techniques for noise reduction in the transformer?

16) List the properties of the transformer oil with its limiting value?

17) Explain the following terms with regards to property of oil:

(i) Viscosity

(ii) Loss Tangent

18) What is importance of insulation resistance? Define polarization Index.


1) Explain factors affecting the life of Transformer.

2) Explain the maintenance schedule for up to 1000KVA Transformer at Every Year.

3) Explain Transformer Test.

1. Dielectric Strength Test

2. Crackle Test

3. Acidity Test

4. Sludge Test

5. Flash-Point Test

4) Explain Measurement of insulation resistance by Megger.

5) What are the possible reasons for failure of distribution Transformer?

6) Draw and explain the line Diagram of mobile Oil fileration plant.

7) What are the possible causes of Audible Noise in the Transformer?

8) Which are the tests to be performed on the transformer oil? Explain any two.


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Chapter: - 3 Commissioning and Recharging of

Transformer


1) What are the Pre-Commissioning checking of the power Transformer?

2) List out any four primary injection test of power Transformer.

3) Which are the commissioning tests to be performed on Buchholz Relay?

4) Define: - Absorption Coefficient.

5) Classify the routine test on a Power Transformer.

6) Which of the following Megger reading should be high, and why?

1. InR0

2. InR60

7) Which are the factors affecting the insulation of the Transformer winding?

8) What are the factors to be considered while measuring resistance by Kelvin’s Bridge method?

9) What is purpose of magnetizing current test of power Transformer?

10) Classify the routine test on a power Transformer.

11) Which are the commissioning tests to be performed on Buchholz relay?

12) Which is the common earthing of the power transformer?

13) What should be limiting values of ratio error during voltage ratio test of the transformer?

14) What should be possible reason if the Buchholz relay is operated during energizing of distribution

transformer first time?

15) What is general rule of value of insulation resistance per KV operating voltage in the

transformer?


1) Classify the different test on a Power Transformer.

2) Write the short note on Polarization Index.

3) Explain any one method for measurement of winding resistance.

4) How to measure transformer winding resistance by Kelvin’s Bridge?

5) Explain the Voltage ratio test for a Transformer.

6) How to check continuity test on a single phase transformer?

7) State the steps prior to commissioning of a power transformer.

8) Explain insulation resistance test on a power transformer.


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1) What is importance of magnetizing Current test? How this test is carried out?

2) What are the general check points for pre-Commissioning of the power Transformer?

3) Classify routine test, Type test and special test on a transformer?

4) Explain the procedure of energizing of the power transformer.

5) What are the Commissioning tests of the power Transformer?

6) Explain Grounding of the power Transformer.

7) Describe the various steps for checking on Load tap changer.

Chapter – 4 Maintenance of Circuit Breaker


1) What are the possible reasons for maintenance of the Circuit Breaker?

2) What is purpose of Millivolt test on a Circuit Breaker?

3) What is effect of nitrogen or air in the SF6 and TRV?

4) What is function of motion analyzer?

5) Define : Arcing time

6) How the inspection of Gaskets is done during the maintenance of the Circuit Breaker?

7) What are the check pints during maintenance of insulation in the SF6 Circuit Breaker?

8) Write the full form of: MOCB, ABCB, and MCCB.

9) How the pressure between the contacts of Circuit Breaker is measured.

10) Write any two safety practices before maintenance of Circuit Breaker.

11) Write two properties of SF6 gas.

12) What is post fault maintenance of SF6 Circuit Breaker?

13) Explain any one routine test to be performed on moulded case Circuit Breaker.

14) What are the safety practices to be taken in medium voltage Circuit Breaker?

15) Why the line and load terminals are disconnect during measurement of insulation resistance

between them?

16) Why the connection test is carried out on the moulded case circuit breaker?

17) What are the possible check points for operating mechanisms in the circuit breaker?

18) What is function of gas heaters in the SF6 circuit breaker?

19) What are the check points after faults in the vacuum circuit breaker?

20) Why the interruption of line charging current causes more detritions than interruption of heavy

fault current for the same rating of oil circuit breaker?


1) Explain routine test to be performed on moulded case Circuit Breaker

2) Write the general maintenance procedure steps in low voltage Circuit Breaker.


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3) Write the general maintenance procedure steps in Medium voltage Oil Circuit Breaker

4) Write the general maintenance procedure steps in low voltage Air Circuit Breaker

5) Write the maintenance procedure steps for the following parts of Oil circuit breaker:

a. Interpole Linkage

b. Interrupts

c. Filter

6) Explain the maintenance steps for the following components of Circuit Breaker:

a. Contacts

b. Opening mechanisms

c. Relay

7) Explain the maintenance of MCCB.

8) Explain the various steps in maintenance of circuit breaker.

9) Explain the maintenance steps for the following components of circuit breaker:

(i) Contacts

(ii) Opening mechanisms

(iii) Relay

10) What are the difficulties to be observed during internal inspections of high voltage circuit breaker

11) What are the effects of light duty on the performance of high voltage circuit breaker?

12) What are the effects of normal duty on the performance of high voltage circuit breaker?

13) What are the properties of SF6 Gas?

14) How the maintenance of arcing contacts is done in the oil circuit breaker?

15) What are the causes of failure of circuit breaker?

16) What are the safety precautions to be taken during maintenance of circuit breaker?

17) Draw the single line diagram of Centrifugal oil purifier.

18) Prepare a test report for the inspection of HT/LT parts during maintenance of the substation.


1) Explain different types of tests on High voltage AC Circuit Breaker

2) Explain maintenance of Oil Circuit Breaker

3) Explain maintenance of SF6 Circuit Breaker

4) Explain Handling faults of SF6 Gas.

5) What are the causes of failure of Circuit Breaker?

6) How the monitoring and handling of SF6 Gas is carried out in the SF6 Circuit Breaker.

7) Explain trouble shooting chart for the circuit breaker.

8) Explain the maintenance procedure of vacuum circuit breaker.

9) Write the general steps for external & internal inspection of high voltage circuit breaker.

10) Explain the maintenance procedure of the Moulded case circuit breaker.


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ASSIGNMENT - rcti.cteguj.in · SWITCH GEAR & PROTECTION CHAPTER-1 ... Reset value c) Stability d) ... Obtain the equation produced in induction disc relay. Q4. What is mean by IDMT?