The penetration is an element of a nuclear containment structure used for the passage of the electric cables through an aperture in the nuclear containment structure

1. A PRESENTATION
ON
GAS INSULATED
SUBSTATION

2. PRINCIPLE OF GIS
IT IS BASED ON THE PRINCIPLE OF
COMPLETE ENCLOSURE OF ALL
ENERGISED PARTS IN A METALLIC
ENCLOSURES WHICH SHIELDS FROM THE
EXTERNAL ENVIRONMENT.

3. ADVANTAGE OF GIS
 Compactness : The space occupied by the GIS installation is
only about 10% of Conventional switch yard.
 Protection from : Highly preferred in coastal areas where
Pollution effect due to salt deposition is very high.
 Superior Arc : The system has better Arc quenching
interruption capability because of higher dielectric
strength.
 Maintenance free : The equipments require minimum
maintenance once installed properly. The
cost on maintenance will be reduced
considerably.
 Increased safety : Owing to very high insulation level and since
the enclosures are at earth potential, there is
no possibility of Electric accident.

4. INSULATION IN GIS
Sulphur Hexa Fluoride (SF6) is used as an
Insulating medium between Enclosures
and Current carrying bus bars.

5. PROPERTIES OF SF6
 Dielectric Strength :The Dielectric strength of SF6 is
about 2.5 to 3 times higher than the corresponding
values of Air.
 Arc Quenching Capacity : The Thermal Properties and
Low ionisation temperature of SF6 exhibits outstanding
Characteristics for extinguishing electric arcs. The arc
quenching time using SF6 is about 100 times less than
that using air.
 Heat Transferability : The heat transferability is 2 to
2.5 times that of air at same pressure. Hence for equal
conductor size, the current carrying capacity is relatively
more.

6. PROPERTIES OF SF6
Low Arc time constant : Because of the
Electronegative property of SF6, the arc
time constant is very low and the rate of
rise of dielectric strength is very high.
Inert : Since the gas is inert the inside
compartments do not get oxidised or
deteriorated.

8. INSTALLATION OF GIS
CIVIL COMPLETION
EQUIPMENT ERECTION
GAS TREATMENT
TESTING
COMMISSIONING

9. CIVIL COMPLETION
EOT CRANE ERECTION & COMMISSIONING
LIGHTING & VENTILATION WORKS
COMPLETE PAINTNG INCLUDING EPOXY FLOOR
FINISH

10. CIVIL CHECKS
FIX THE REFERENCE LINE OF CB
FIX THE REFERENCE LINE OF BUS BAR
ERECTION & ALIGNMENT OF HALFEN BEAMS

11. ERECTION OF GIS EQUIPMENTS
INDOOR
OUTDOOR

12. INDOOR ERECTION
ERECTION OF CIRCUIT BREAKERS
ERECTION OF DISCONNECTORS
ERECTION OF ENCLOSURES & BUS BARS
ERECTION OF CURRENT TRANSFORMER
ERECTION OF VOLTAGE TRANSFORMER

13. TYPICAL CIRCUIT BREAKER
WITH OUT CLOSING RESISTOR
1. CIRCUIT BREAKER
2. HYDRAULIC OPERATING
MECHANISM
3. DISCONNECTOR
4. EARTH SWITCH
5. CURRENT TRANSFORMER
6. VOLTAGE TRANSFORMER
7. CABLE CONNECTION

14. TYPICAL CIRCUIT BREAKER
WITH CLOSING RESISTOR
1. CIRCUIT BREAKER WITH
CLOSING RESISTOR
2. HYDRAULIC OPERATING
MECHANISM
3. DISCONNECTOR
4. EARTH SWITCH
5. CURRENT TRANSFORMER
6. VOLTAGE TRANSFORMER
7. CABLE CONNECTION

15. TYPICAL ARRANGEMENT OF
DISCONNECTORS

16. TYPICAL ARRANGEMENT OF
CURRENT TRANSFORMER
1. MAIN CONDUCTOR
2. SECONDARY WINDING
3. SHUNT
4. INSULATING PART

17. TYPICAL ARRANGEMENT OF
VOLTAGE TRANSFORMER

18. TYPICAL CONNECTION
ARRANGEMENT OF GIS WITH
TRANSFORMER
1. CONNECTING CONTACT
2. SF6 / OIL BUSHING
3. REMOVABLE LINK
4. SERVICE UNIT

19. TYPICAL ARRANGEMENT OF SURGE
ARRESTOR & CABLE CONNECTION

20. TYPICAL ARRANGEMENT OF
INSULATING CONES

21. ERECTION OF CIRCUIT BREAKER
THE PACKING MATERIALS MEANT FOR
TRANSPORTATION INSIDE CB TO BE REMOVED
BEFORE ERECTION.
PRESENCE OF NITROGEN TO BE ENSURED.
ALIGNMENT TO BE DONE WITH THEODALITE.
TIGHTNESS OF FOUNDATION BOLT TO BE
DONE STRICTLY AS PER MANUFACTURER’S
RECOMMENDATION.

22. ERECTION OF CIRCUIT BREAKER
TILTING
TOOL

23. ERECTION OF DISCONNECTORS
 PRESENCE OF NITROGEN TO BE ENSURED ON ALL THE
PARTS OF DISCONNECTORS.
 O-RINGS SHOULD BE CHECKED THROUGHLY BEFORE
PLACING THEM IN POSITION.
 GREASE TO BE APPLED EVENLY IN THE O-RING.
 APPLY CONTACT GREASE IN CONTACT PORTION OF
BUS BAR.
 NEVER MIX THE CONTACT GREASE AND THE ONE USED
FOR O-RINGS.
 ENSURE THAT O-RINGS ARE NOT DAMAGED DURING
CONNECTION.

24. ERECTION OF DISCONNECTORS
CB SIDE
CONNECTION
BUS
BAR-I
BUS BAR-
II

25. PREPARATION & ERECTION OF
BUS BAR
BUS BARS SHALL BE THROUGHLY CLEANED
WITH ISOPROPANOL.
ANY PROTRUSION IN THE BUS BAR SHOULD BE
REMOVED WITH FINE EMERY PAPER.
THE SPRING CONTACTS SHOULD BE IN
POSITION DURING CONNECTION.
NO SCRATCHES IN THE BUS BAR IS ALLOWED.

26. PREPARATION & ERECTION OF
BUS BAR

27. ERECTION OF CT
 CHECK FOR ANY DAMAGE ON THE SECONDARY CORES
OF CT.
 PRESENCE OF NITROGEN TO BE ENSURED ON ALL THE
PARTS OF DISCONNECTORS.
 PERFORM THE FUNCTIONAL CHECKS.
 CHECK THE INTERNAL PART OF ENCLOSURES FOR
PROTRUSIONIF ANY.
 PERFORM THE ERECTION DEPENDING ON THE
ARRANGEMNT EITHER WITH ENCLOSURES OR
DIRECTLY WITH EQUIPMENT.

28. ERECTION OF CT IN GENERATOR BAY
CONNECTION
UNDER
PROGRESS
WITH CB

29. ERECTION OF VOLTAGE
TRANSFORMER
 CHECK VT FOR DAMAGE IF ANY WITH THE VIBRATION
INDICATOR PROVIDED.
 NEVER OPEN THE COVER AS POSITIVE PRESSURE OF
SF6 IS MAINTAINED INSIDE.
 PERFORM FUNCTIONAL CHECKS.
 PERFORM THE ERECTION.

30. OUTDOOR ERECTION
 PREPARE A PLATFORM FOR ASSEMBLY OF VARIOUS
EQUIPMENTS.
 PREPARE A MOBILE SHED (PREFERABLY WITH WOOD)
FOR CONNECTION.
 NEVER KEEP ANY EQUIPMENT UNDER OPEN POSITION.
ALWAYS COVER WITH POLYTHENE PAPER TO AVOID
ENTRY OF FOREIGN PARTICLE.

31. EQUIPMENTS TOBE ERECTED
OUTDOOR
LIGHTNING ARRESTORS
SF6 / AIR BUSHING
TRANSFORMER END CONNECTION

32. ERECTION OF LIGHTNING
ARRESTORS
ACTIVE PART SHALL BE THROUGHLY
CLEANED TO REMOVE FOREIGN MATTER.
POSITIONING OF Zno IN EACH STACK
SHALL BE CHECKED.
ENSURE PROPER PLACING OF ACTIVE
PART INSIDE ENCLOSURE.

33. ERECTION OF ACTIVE PART
LA ACTIVE
PART
ENCLOSURE
FOR ACTIVE
PART

34. ERECTION OF SF6/ AIR BUSHING
 THIS IS END PORTION OF GIS FOR EVACUATION OF
POWER.
 CHECK FOR PHYSICAL DAMAGE OF INSULATORS.
 PERFORM THE CONNECTION OF ENCLOSURE WITH
BUSHING.
 MAKE SUITABLE PLATFORM FOR ERECTION OF
BUSHING WITH INSIDE BAY.
 PREPARE THE ROLLER SUPPORT ON THE WALL BEFORE
ERECTION OF ENCLOSURE .

35. INSIDE VIEW OF BUSHING WITH
BUS BAR
DOUBLE SEAL
ARRANGEMENT
TEMPORARY SUPPORT
OF BUS BAR

36. ERECTION OF BUSHING

37. HYDRAULIC OPERATING
MECHANISM
 THE BREAKER OPERATION IS THROUGH HYDRAULIC
OPERATING MECHANISM.
 DURING FILLING OF OIL CARE SHOULD BE TAKEN TO
AVOID AIR TRAP INSIDE.
 NITROGEN ACCUMULATORS ARE PROVIDED TO FASTER
OPERATION OF CB DURING OPEN & CLOSE
OPERATIONS.

38. DRIVE ROD MECHANISM
THE DISCONNECTORS OF ALL THE PHASES
SHALL BE IN OPEN POSITION BEFORE
ASSEMBLY.
NUMBER OF ROTATIONS SHALL BE AS PER
MANUFACTURER’S RECOMMENDATION.
MECHANICAL INTERLOCK IF ANY IS TO BE
PROVIDED BETWEEN DISCONNECTOR AND
EARTH SWITCH.

39. CABLE TRAYS, CABLING
 THE CABLE TRAYS WORK CAN BE STARTED ONCE A
COMPLETE BAY IS ERECTED.
 CABLING WORK CAN BE STARTED ONCE PART OF
CABLE TRAY ERCTION IS OVER.

40. EARTHING
SINCE THE ENCLOSURE IS ALUMINIUM, IT
OFFERS CONTINUITY.
WHEREVER FLANGE JOINTS ARE THERE, THE
PAINTING SHALL BE PROPERLY REMOVED.
THE FLANGES OF SHALL BE SHORTED ACROSS
CT WITH EARTH FLATS.
VARISTORS SHALL BE PROVIDED IN THE CT
JOINT. THIS IS TO AVOID THE DAMAGE OF CT
OWING TO SWITCHING TRANSIENTS.

41. GAS TREATMENT
THE VACCUM PUMP SHALL BE USED TO CREATE
VACCUM INSIDE THE BAY WHICH IS READY.
CHECK WITH GAUGE THE EXTENT OF VACCUM.
MAINTAIN IT FOR 12 HOURS.
PURGE THE BAY WITH NITROGEN IF
MOISTURE IS IN EXCESS.
CONTINUE THE VACCUM PROCESS TILL THE
DESIRED LEVEL IS REACHED.

42. VACCUM PUMP & GAS
TREATMENT CART

43. GAS TREATMENT
 DILO CART SHALL BE MADE VACCUM BEFORE ACTUAL
FILLING STARTS.
 THE SF6 GAS FILLING SHALL BE GRADUAL.
 SF6 BEING A HEAVIER GAS WILL SETTLE DOWN AT
THE BOTTOM. ADEQUATE CARE SHALL BE TAKEN.
 NEVER KEEP THE HOSES OPEN WHEN SF6 GAS IS NOT
FILLED.
 SF6 SHALL BE FILLED IN EACH COMPARTMENTS AT
REQUIRED PRESSURE AS PER MANUFACTURER’S
RECOMMENDATION.

44. TESTING
HYDRAULIC CHECKING
LCC CONTROL CHECKING
CT TESTING
SF6 GAS CHECKING
OPERATION CHECKING OF DRIVE MECHANISM
TESTING OF PRESSURE SWITCH
CONTACT RESISTANCE CHECKING

45. HYDRAULIC CHECKING
ENSURE ENOUGH OIL IS TOPPED UP INSIDE
THE TANK.
ALLOW THE OIL TO FLOW TILL NO AIR
BUBBLES ARE TRAPPED INSIDE.
THE PRESSURE SWITCH FOR HYDRAULIC
MECHANISM AT EACH LEVELS SHALL BE
CHECKED AS PER MANUFACTURER’S
RECOMMENDATION.

46. TYPICAL PRESSURE SCALE

47. HV TESTING
ONCE ALL THE CONTROL CHECKING IS OVER
THEN THE EQUIPMENT IS READY FOR HV
TESTING.
THE ASSEMBLY OF HV TEST KIT ALONG WITH
CONTROL EQUIPMENTS SHALL BE DONE.

48. TYPICAL ARRANGEMENT OF HV
TESTING KIT

49. POINTS TO BE NOTED PRIOR TO
HV TESTING
SF6 GAS PRESSURE IS CHECKED IN ALL THE
COMPARTMENTS.
CT SECONDARY TERMINALS ARE SHORTED.
VOLTAGE TRANSFORMER IS DICONNECTED.
LIGHTNING ARRESTOR IS DICONNECTED.
CABLE CONNECTION IS DISCONNECTED.
SF6/AIR BUSHING IS THROUGHLY CLEANED.

50. DISMANTLING ARRANGEMENT OF
BUS BARS