SlideShare ist ein Scribd-Unternehmen logo
1 von 26
Downloaden Sie, um offline zu lesen
BY: Ashok khoja
 AT 132 KV GSS
 NEEM KA THANA
• GENERAL DISCUSSION ON SUB STATIONS
• SINGLE LINE DIAGRAM
• COMPONENTS USED
• ISOLATERS
• BUSBARS
• CIRCIUT BREAKERS AND ITS CLASSIFICATION
• POWER TRANSFORMERS AND ITS MAIN PARTS
• INSTRUMENT TRANSFORMERS
• CURRENT TRANSFORMERS
• BUCHOLZ RELAY
• EARTHING
• POWER LINE CARRIER COMMUNICATION
Substation:- A station is a subsidiary station of an
  electricity generation, transmission, & distribution system
  where voltage is transformed to high to low or the reverse
  using transformers.
A substation generally have switching, protection, & control
  equipment & one or more transformers.
Types:-
(a) Transmission substation
(b) Distribution substation
Transmission substation connects two or more
    transmission lines.
Distribution substation transfers power from transmission
    system to the distribution system of an area.
Ppt on  132 kv gss  by ashok khoja
COMPONENTS USED
 • ISOLATERS

 • CIRCIUT BREAKERS

 • INST. TRANSFORMERS

 • RELAYS
 Isolators are designed to open a ckt under n0 load. Its
  main purpose is to isolate portion of ckt from the
  other & is not intended to be opened while current is
  flowing in the line.
 There are two types of isolators:-
 off load isolators
 on load isolators
DEFINITION:- A bus bar is a conducting bar that
  carries heavy currents to supply several electric
  circuits.
When a no. of generators or feeders operating at the
  same voltage level to be directly connected electrically,
  busbar are used as the common electrical component.
  Bus bars are copper rod or thin walled tubes and
  operate at constant voltage.
TYPES OF BUSBARS:-
 Main busbar
 Auxiliary busbar
One busbar is main busbar & another is spare or auxilary
  busbar.
A circuit breaker is a piece of equipment which can:-
 break a ckt automatically under fault conditions.
 make a ckt either manually or by remote control
  under fault conditions.
PRINCIPLE:- A ckt breaker essentially consists of
  fixed & moving contacts, called electrodes under
  normal operating conditions, these contacts remain
  closed & will not open automatically until & unless the
  systems becomes faulty. When a fault occurs on any
  part of the system, the trip coils of the breaker get
  energised & the moving contacts are pulled apart by
  some mechanism. Thus opening the circuit.
CLASSIFICATION:-
 oil circuit breakers
 Sulphur Hexa Fluoride circuit breakers
 Air-Blast circuit breakers
 vaccum circuit breakers
 Under training SF6 type, vaccum ckt breaker & Air-
 Blast ckt breakers were used in the GSS.
Ppt on  132 kv gss  by ashok khoja
Transformer is an electrical machine which works on
  the principle of electromagnetic induction. It transfers
  electric power from one electric ckt to other with the
  help magnetic path(flux) on constant frequency but
  equal or different current voltages. For this purpose
  two sets of insulated windings are wounded on a close
  terminated steel core. The winding which is connected
  to the supply is called primary winding & that winding
  is connected to the load is called secondary winding.
MAIN PARTS OF POWER
  TRANSFORMERS:-
a) core
b) Winding(H.V winding, L.V winding, tertiary
   winding)
c) Tap changer
d) Tank
e) Conservator
f) Air cell
g) Buchholz relay
h) Dehydrating breather
i) Oil temperature indicator
j) Winding temperature indicator
Ppt on  132 kv gss  by ashok khoja
Instrument transformers are used for measurement
 and protective applications together with equipments
 such as meters & relays.
The lines in a station are operated at high voltages and
 carry currents of thousands of amperes. The
 measuring and protective devices are designed for low
 voltage generally 100v and currents about 5A, therefore
 they will not work satisfactory if mounted on the
 power lines. This difficulty can be overcome by using
 instrument transformers, which will step down the
 voltages and currents to the convenient level for the
 operation of measuring instruments & relays.
 C.T. is an instrument transformer used for protection &
    metering of high values of currents. C.T. is used for
    reducing a.c from higher to lower value for
    measurement/protection/control. There are two classes of
    C.T:
    protective C.T
    measuring C.T
   Protective C.Ts are used for over current protection, earth
    fault protection, differential protection& impedence
    protection, etc.
   Measuring C.Ts are used with ammeters, wattmeters, KV
    meters & KWH meters for reducing line.
Ppt on  132 kv gss  by ashok khoja
Potential transformers are instrument transformers. They
 have a large number of secondary turns and a fewer
 number of primary turns. They are used to increase the
 range of voltmeters in electrical substations and generating
 stations.
These are also called as voltage transformers used for line and
 circuit protections.
Ppt on  132 kv gss  by ashok khoja
Definition:- Buchholz relay is a gas actuated relay. It
 can only be fitted to the transformers equipped with
 conservator tanks as it is installed in b/w the
 conservator tank and the main tank i.e., the pipe
 connecting the two.
Principle:- Whenever a fault occurs inside the
 transformers, the oil of the tank gets overheated and
 gases are generated.
The heat generated by the high local current causes the
 transformer oil to decompose and produce gas which
 can be used to detect the faults.
Operation:- When a fault occurs, heat is produced
 due to current leakage, some of the oil in the
 transformer tank evaporates and some vapours
 collect in the top of the chamber while passing to
 conservator tank. When a predetermined amount
 of vapours accumulate in the top of the chamber,
 the oil level falls, and so closes the alarm circuit of
 the relay and rings the bell. Thereby the operator
 knows that there is some fault occurred in the
 transformer.
Ppt on  132 kv gss  by ashok khoja
Connection of an electric equipment to the earth
 with the help of connecting rod or wire of
 negligible resistance is known as earthling.
 Methods of earthling arrangements at 132
 kv GSS:
 pipe earthling
 plate earthling
Ppt on  132 kv gss  by ashok khoja
For exchange of datas and transfer message between
 grid substation, voice communication is necessary.
 for this purpose high frequency carrier current is
 transmitted on same transmission line on which
 power is transmitted.
Hence such communication is called “power line
 carrier communication’’.
Ppt on  132 kv gss  by ashok khoja
Ppt on  132 kv gss  by ashok khoja

Weitere ähnliche Inhalte

Was ist angesagt?

220 kv Sub-station Summer Training ppt
220 kv Sub-station Summer Training ppt220 kv Sub-station Summer Training ppt
220 kv Sub-station Summer Training pptShubham Patel
 
PPt on 220 kV substation
PPt on 220 kV substationPPt on 220 kV substation
PPt on 220 kV substationIshank Ranjan
 
132KV SUBSTATION UPPTCL
132KV SUBSTATION UPPTCL132KV SUBSTATION UPPTCL
132KV SUBSTATION UPPTCLAman Rajput
 
Industrial summer training on 220 kv substation ppt
Industrial summer training on 220 kv substation pptIndustrial summer training on 220 kv substation ppt
Industrial summer training on 220 kv substation pptAshutosh Srivastava
 
132 kv substation
132 kv substation132 kv substation
132 kv substationWipro
 
Sub station training ppt
Sub station training pptSub station training ppt
Sub station training pptsitesh95074
 
A training report on 132 KV GSS, BHADOTI, sawai madhopur
A training report on 132 KV GSS, BHADOTI, sawai madhopurA training report on 132 KV GSS, BHADOTI, sawai madhopur
A training report on 132 KV GSS, BHADOTI, sawai madhopurdilkhush009
 
SUB-STATION DESIGN AND PROTECTION (AN OVERVIEW)
SUB-STATION DESIGN AND PROTECTION  (AN OVERVIEW)SUB-STATION DESIGN AND PROTECTION  (AN OVERVIEW)
SUB-STATION DESIGN AND PROTECTION (AN OVERVIEW)Ameh Messiah Edache
 
Electrical substations: 132 KV
Electrical substations: 132 KV Electrical substations: 132 KV
Electrical substations: 132 KV Girish Gupta
 
Electric substation
Electric substation Electric substation
Electric substation ANNU KUMAR
 
Visit to 400 kV substation, Hadala
Visit to 400 kV substation, HadalaVisit to 400 kV substation, Hadala
Visit to 400 kV substation, HadalaNandan Desai
 
132kv Gss report of sitapura jaipur
132kv Gss report of sitapura jaipur132kv Gss report of sitapura jaipur
132kv Gss report of sitapura jaipurkishankky
 
132 33kv substation documentation
132 33kv substation documentation132 33kv substation documentation
132 33kv substation documentationRajashekar Gurrala
 

Was ist angesagt? (20)

220 kv Sub-station Summer Training ppt
220 kv Sub-station Summer Training ppt220 kv Sub-station Summer Training ppt
220 kv Sub-station Summer Training ppt
 
220 kv gss
220 kv gss220 kv gss
220 kv gss
 
PPt on 220 kV substation
PPt on 220 kV substationPPt on 220 kV substation
PPt on 220 kV substation
 
132 kv
132 kv132 kv
132 kv
 
132KV SUBSTATION UPPTCL
132KV SUBSTATION UPPTCL132KV SUBSTATION UPPTCL
132KV SUBSTATION UPPTCL
 
Industrial summer training on 220 kv substation ppt
Industrial summer training on 220 kv substation pptIndustrial summer training on 220 kv substation ppt
Industrial summer training on 220 kv substation ppt
 
132 kv substation
132 kv substation132 kv substation
132 kv substation
 
Sub station training ppt
Sub station training pptSub station training ppt
Sub station training ppt
 
5. Switchyard & Substation
5. Switchyard & Substation5. Switchyard & Substation
5. Switchyard & Substation
 
A training report on 132 KV GSS, BHADOTI, sawai madhopur
A training report on 132 KV GSS, BHADOTI, sawai madhopurA training report on 132 KV GSS, BHADOTI, sawai madhopur
A training report on 132 KV GSS, BHADOTI, sawai madhopur
 
PPT ON 220KV GSS
PPT ON 220KV GSSPPT ON 220KV GSS
PPT ON 220KV GSS
 
SUB-STATION DESIGN AND PROTECTION (AN OVERVIEW)
SUB-STATION DESIGN AND PROTECTION  (AN OVERVIEW)SUB-STATION DESIGN AND PROTECTION  (AN OVERVIEW)
SUB-STATION DESIGN AND PROTECTION (AN OVERVIEW)
 
Electrical substations: 132 KV
Electrical substations: 132 KV Electrical substations: 132 KV
Electrical substations: 132 KV
 
Electric substation
Electric substation Electric substation
Electric substation
 
Summer Training presentation on 132/33 KV sub-station Minto park, Allahabad
Summer Training presentation on 132/33 KV sub-station Minto park, AllahabadSummer Training presentation on 132/33 KV sub-station Minto park, Allahabad
Summer Training presentation on 132/33 KV sub-station Minto park, Allahabad
 
Visit to 400 kV substation, Hadala
Visit to 400 kV substation, HadalaVisit to 400 kV substation, Hadala
Visit to 400 kV substation, Hadala
 
132kv Gss report of sitapura jaipur
132kv Gss report of sitapura jaipur132kv Gss report of sitapura jaipur
132kv Gss report of sitapura jaipur
 
132 33kv substation documentation
132 33kv substation documentation132 33kv substation documentation
132 33kv substation documentation
 
220 kv gss dausa
220 kv gss dausa220 kv gss dausa
220 kv gss dausa
 
ppt
pptppt
ppt
 

Andere mochten auch

132 KV Grid Station Intern ship training report
132 KV Grid Station Intern ship training report132 KV Grid Station Intern ship training report
132 KV Grid Station Intern ship training reportMuntazir Mehdi
 
Sisener Substation Engineering
Sisener Substation EngineeringSisener Substation Engineering
Sisener Substation EngineeringGiuseppe di Siena
 
Evaluation Question
Evaluation QuestionEvaluation Question
Evaluation QuestionBroganOBrien
 
Staying Connected While on Vacation - Infographic
Staying Connected While on Vacation - InfographicStaying Connected While on Vacation - Infographic
Staying Connected While on Vacation - InfographicPertino
 
Pertino Overview for the IT Generalist
Pertino Overview for the IT GeneralistPertino Overview for the IT Generalist
Pertino Overview for the IT GeneralistPertino
 
How to Enable File and Print Sharing on Windows
How to Enable File and Print Sharing on WindowsHow to Enable File and Print Sharing on Windows
How to Enable File and Print Sharing on WindowsPertino
 
Comparing Your IT Networking Options
Comparing Your IT Networking OptionsComparing Your IT Networking Options
Comparing Your IT Networking OptionsPertino
 
How to Enable Screen Sharing on Mac
How to Enable Screen Sharing on MacHow to Enable Screen Sharing on Mac
How to Enable Screen Sharing on MacPertino
 
Fast Answers about Pertino
Fast Answers about PertinoFast Answers about Pertino
Fast Answers about PertinoPertino
 

Andere mochten auch (19)

132 KV GSS CHAMBAL JAIPUR
132 KV GSS CHAMBAL JAIPUR132 KV GSS CHAMBAL JAIPUR
132 KV GSS CHAMBAL JAIPUR
 
132 KV Grid Station Intern ship training report
132 KV Grid Station Intern ship training report132 KV Grid Station Intern ship training report
132 KV Grid Station Intern ship training report
 
Sisener Substation Engineering
Sisener Substation EngineeringSisener Substation Engineering
Sisener Substation Engineering
 
Evaluation Question
Evaluation QuestionEvaluation Question
Evaluation Question
 
Demokrasi
DemokrasiDemokrasi
Demokrasi
 
STRATIFIKASI
STRATIFIKASISTRATIFIKASI
STRATIFIKASI
 
Staying Connected While on Vacation - Infographic
Staying Connected While on Vacation - InfographicStaying Connected While on Vacation - Infographic
Staying Connected While on Vacation - Infographic
 
UFO infographic
UFO infographicUFO infographic
UFO infographic
 
Pertino Overview for the IT Generalist
Pertino Overview for the IT GeneralistPertino Overview for the IT Generalist
Pertino Overview for the IT Generalist
 
How to Enable File and Print Sharing on Windows
How to Enable File and Print Sharing on WindowsHow to Enable File and Print Sharing on Windows
How to Enable File and Print Sharing on Windows
 
Bab ii
Bab iiBab ii
Bab ii
 
My task presentation general
My task presentation generalMy task presentation general
My task presentation general
 
Bab i
Bab iBab i
Bab i
 
HADITS SHOHIH
HADITS SHOHIHHADITS SHOHIH
HADITS SHOHIH
 
Media
MediaMedia
Media
 
Comparing Your IT Networking Options
Comparing Your IT Networking OptionsComparing Your IT Networking Options
Comparing Your IT Networking Options
 
Wk1 disc2
Wk1 disc2Wk1 disc2
Wk1 disc2
 
How to Enable Screen Sharing on Mac
How to Enable Screen Sharing on MacHow to Enable Screen Sharing on Mac
How to Enable Screen Sharing on Mac
 
Fast Answers about Pertino
Fast Answers about PertinoFast Answers about Pertino
Fast Answers about Pertino
 

Ähnlich wie Ppt on 132 kv gss by ashok khoja

132 gss ppt
132 gss ppt132 gss ppt
132 gss ppthunk143
 
DISTRIBUTION SYSTEM OPERATION AND CONTROL
DISTRIBUTION SYSTEM OPERATION AND CONTROLDISTRIBUTION SYSTEM OPERATION AND CONTROL
DISTRIBUTION SYSTEM OPERATION AND CONTROLyohannes feleke
 
Presentation training
Presentation trainingPresentation training
Presentation trainingSrajan Raj
 
Substation_equipment_ (1).pptx
Substation_equipment_ (1).pptxSubstation_equipment_ (1).pptx
Substation_equipment_ (1).pptxSatish Pydimarla
 
Substation Training presentation
Substation Training presentationSubstation Training presentation
Substation Training presentationKamal Mittal
 
Sharavati receiving station
Sharavati  receiving stationSharavati  receiving station
Sharavati receiving stationH.C.Naveen Kumar
 
Report on 220kv substation at Jassure
Report on 220kv substation at JassureReport on 220kv substation at Jassure
Report on 220kv substation at JassureShuvam Pathania
 
Load Distribution
Load DistributionLoad Distribution
Load DistributionArpit Gupta
 
Ppt on 400 kv gss raiser Bikaner- Yatendra Parashar
Ppt on 400 kv gss raiser Bikaner- Yatendra ParasharPpt on 400 kv gss raiser Bikaner- Yatendra Parashar
Ppt on 400 kv gss raiser Bikaner- Yatendra ParasharYatendra Parashar
 
Uttar pradesh power corporation limited
Uttar pradesh power corporation limitedUttar pradesh power corporation limited
Uttar pradesh power corporation limitedVSRAGHU
 
Vocational Training Report ( Sealdah Power House)
Vocational Training Report ( Sealdah Power House)Vocational Training Report ( Sealdah Power House)
Vocational Training Report ( Sealdah Power House)shovandey07
 
PPT ON 33/11KV SUBSTATION
PPT ON 33/11KV SUBSTATIONPPT ON 33/11KV SUBSTATION
PPT ON 33/11KV SUBSTATIONRavi Phadtare
 
pptravi-191011011024 (1).pdf
pptravi-191011011024 (1).pdfpptravi-191011011024 (1).pdf
pptravi-191011011024 (1).pdfHariomgupta90
 
Madan mohan malaviya
Madan mohan malaviyaMadan mohan malaviya
Madan mohan malaviyaAnuj Bansal
 
Switchyard final
Switchyard finalSwitchyard final
Switchyard finalHAIDER ALI
 

Ähnlich wie Ppt on 132 kv gss by ashok khoja (20)

132 gss ppt
132 gss ppt132 gss ppt
132 gss ppt
 
Gss ppt by kanhaiya
Gss ppt  by kanhaiyaGss ppt  by kanhaiya
Gss ppt by kanhaiya
 
DISTRIBUTION SYSTEM OPERATION AND CONTROL
DISTRIBUTION SYSTEM OPERATION AND CONTROLDISTRIBUTION SYSTEM OPERATION AND CONTROL
DISTRIBUTION SYSTEM OPERATION AND CONTROL
 
rough.pptx
rough.pptxrough.pptx
rough.pptx
 
Presentation training
Presentation trainingPresentation training
Presentation training
 
Substation_equipment_ (1).pptx
Substation_equipment_ (1).pptxSubstation_equipment_ (1).pptx
Substation_equipment_ (1).pptx
 
Ashish.pptx
Ashish.pptxAshish.pptx
Ashish.pptx
 
Substation Training presentation
Substation Training presentationSubstation Training presentation
Substation Training presentation
 
ntpc
ntpcntpc
ntpc
 
Ashwani kumar
Ashwani kumarAshwani kumar
Ashwani kumar
 
Sharavati receiving station
Sharavati  receiving stationSharavati  receiving station
Sharavati receiving station
 
Report on 220kv substation at Jassure
Report on 220kv substation at JassureReport on 220kv substation at Jassure
Report on 220kv substation at Jassure
 
Load Distribution
Load DistributionLoad Distribution
Load Distribution
 
Ppt on 400 kv gss raiser Bikaner- Yatendra Parashar
Ppt on 400 kv gss raiser Bikaner- Yatendra ParasharPpt on 400 kv gss raiser Bikaner- Yatendra Parashar
Ppt on 400 kv gss raiser Bikaner- Yatendra Parashar
 
Uttar pradesh power corporation limited
Uttar pradesh power corporation limitedUttar pradesh power corporation limited
Uttar pradesh power corporation limited
 
Vocational Training Report ( Sealdah Power House)
Vocational Training Report ( Sealdah Power House)Vocational Training Report ( Sealdah Power House)
Vocational Training Report ( Sealdah Power House)
 
PPT ON 33/11KV SUBSTATION
PPT ON 33/11KV SUBSTATIONPPT ON 33/11KV SUBSTATION
PPT ON 33/11KV SUBSTATION
 
pptravi-191011011024 (1).pdf
pptravi-191011011024 (1).pdfpptravi-191011011024 (1).pdf
pptravi-191011011024 (1).pdf
 
Madan mohan malaviya
Madan mohan malaviyaMadan mohan malaviya
Madan mohan malaviya
 
Switchyard final
Switchyard finalSwitchyard final
Switchyard final
 

Ppt on 132 kv gss by ashok khoja

  • 1. BY: Ashok khoja AT 132 KV GSS NEEM KA THANA
  • 2. • GENERAL DISCUSSION ON SUB STATIONS • SINGLE LINE DIAGRAM • COMPONENTS USED • ISOLATERS • BUSBARS • CIRCIUT BREAKERS AND ITS CLASSIFICATION • POWER TRANSFORMERS AND ITS MAIN PARTS • INSTRUMENT TRANSFORMERS • CURRENT TRANSFORMERS • BUCHOLZ RELAY • EARTHING • POWER LINE CARRIER COMMUNICATION
  • 3. Substation:- A station is a subsidiary station of an electricity generation, transmission, & distribution system where voltage is transformed to high to low or the reverse using transformers. A substation generally have switching, protection, & control equipment & one or more transformers. Types:- (a) Transmission substation (b) Distribution substation Transmission substation connects two or more transmission lines. Distribution substation transfers power from transmission system to the distribution system of an area.
  • 5. COMPONENTS USED • ISOLATERS • CIRCIUT BREAKERS • INST. TRANSFORMERS • RELAYS
  • 6.  Isolators are designed to open a ckt under n0 load. Its main purpose is to isolate portion of ckt from the other & is not intended to be opened while current is flowing in the line.  There are two types of isolators:-  off load isolators  on load isolators
  • 7. DEFINITION:- A bus bar is a conducting bar that carries heavy currents to supply several electric circuits. When a no. of generators or feeders operating at the same voltage level to be directly connected electrically, busbar are used as the common electrical component. Bus bars are copper rod or thin walled tubes and operate at constant voltage. TYPES OF BUSBARS:-  Main busbar  Auxiliary busbar One busbar is main busbar & another is spare or auxilary busbar.
  • 8. A circuit breaker is a piece of equipment which can:-  break a ckt automatically under fault conditions.  make a ckt either manually or by remote control under fault conditions. PRINCIPLE:- A ckt breaker essentially consists of fixed & moving contacts, called electrodes under normal operating conditions, these contacts remain closed & will not open automatically until & unless the systems becomes faulty. When a fault occurs on any part of the system, the trip coils of the breaker get energised & the moving contacts are pulled apart by some mechanism. Thus opening the circuit.
  • 9. CLASSIFICATION:-  oil circuit breakers  Sulphur Hexa Fluoride circuit breakers  Air-Blast circuit breakers  vaccum circuit breakers Under training SF6 type, vaccum ckt breaker & Air- Blast ckt breakers were used in the GSS.
  • 11. Transformer is an electrical machine which works on the principle of electromagnetic induction. It transfers electric power from one electric ckt to other with the help magnetic path(flux) on constant frequency but equal or different current voltages. For this purpose two sets of insulated windings are wounded on a close terminated steel core. The winding which is connected to the supply is called primary winding & that winding is connected to the load is called secondary winding.
  • 12. MAIN PARTS OF POWER TRANSFORMERS:- a) core b) Winding(H.V winding, L.V winding, tertiary winding) c) Tap changer d) Tank e) Conservator f) Air cell g) Buchholz relay h) Dehydrating breather i) Oil temperature indicator j) Winding temperature indicator
  • 14. Instrument transformers are used for measurement and protective applications together with equipments such as meters & relays. The lines in a station are operated at high voltages and carry currents of thousands of amperes. The measuring and protective devices are designed for low voltage generally 100v and currents about 5A, therefore they will not work satisfactory if mounted on the power lines. This difficulty can be overcome by using instrument transformers, which will step down the voltages and currents to the convenient level for the operation of measuring instruments & relays.
  • 15.  C.T. is an instrument transformer used for protection & metering of high values of currents. C.T. is used for reducing a.c from higher to lower value for measurement/protection/control. There are two classes of C.T:  protective C.T  measuring C.T  Protective C.Ts are used for over current protection, earth fault protection, differential protection& impedence protection, etc.  Measuring C.Ts are used with ammeters, wattmeters, KV meters & KWH meters for reducing line.
  • 17. Potential transformers are instrument transformers. They have a large number of secondary turns and a fewer number of primary turns. They are used to increase the range of voltmeters in electrical substations and generating stations. These are also called as voltage transformers used for line and circuit protections.
  • 19. Definition:- Buchholz relay is a gas actuated relay. It can only be fitted to the transformers equipped with conservator tanks as it is installed in b/w the conservator tank and the main tank i.e., the pipe connecting the two. Principle:- Whenever a fault occurs inside the transformers, the oil of the tank gets overheated and gases are generated. The heat generated by the high local current causes the transformer oil to decompose and produce gas which can be used to detect the faults.
  • 20. Operation:- When a fault occurs, heat is produced due to current leakage, some of the oil in the transformer tank evaporates and some vapours collect in the top of the chamber while passing to conservator tank. When a predetermined amount of vapours accumulate in the top of the chamber, the oil level falls, and so closes the alarm circuit of the relay and rings the bell. Thereby the operator knows that there is some fault occurred in the transformer.
  • 22. Connection of an electric equipment to the earth with the help of connecting rod or wire of negligible resistance is known as earthling. Methods of earthling arrangements at 132 kv GSS:  pipe earthling  plate earthling
  • 24. For exchange of datas and transfer message between grid substation, voice communication is necessary. for this purpose high frequency carrier current is transmitted on same transmission line on which power is transmitted. Hence such communication is called “power line carrier communication’’.