In-Country Training On Operation, Maintenance, Protection & Control of 33/11 kV Substation Project Name: Design, Supply, Installation, Testing & Commissioning of 33/11 kV sub-stations with source end feeder bays.   Contract No: BREB/UREDS/W-01A-001/02/2016-2017 BREB/UREDS/W-01A-002/03/2016-2017 BREB/UREDS/W-01A-004/04/2016-2017

1. PRESENTATION
ON BREAKER

2. TRANING ON
 11 KV BREAKER WITH PANEL
 33 KV INDOOR BREAKER WITH PANEL
 33 KV OUTDOOR BREAKER
 RELAY SETTING TOOLS
 SHORT VISIT ON RMU

3. HOW BREAKER WORKS?
A mechanical device capable of making, carrying and breaking currents
under normal conditions as well as under specified abnormal
conditions such as those of short circuit.
Fault Occurs
Relay
• Senses &
Relay Contact
Closes
Circuit Breaker
• Trip Coil Energises
• Operating Mechanism Starts
• Contacts Separate
• Arcing between Contacts
• Arc Extinguishes
• Circuit Breaker Fully Opens Fault Cleared

4. BREAKER INTERUPTING

5. Interrupting media
– Oil
– Air Break
– Air Blast
– Vacuum
– SF6 Puffer
– SF6 Self Blast

6. Dielectric Property Of Various Media
10
Electrode spacing [mm]
20 30
300
250
200
150
100
50
0
-- SF6 (5 Bar)
Vacuum
Oil
-- SF6(1 Bar)
Air(1 Bar)
Disruptivelighteningimpulsevoltage[kV]

7. Dielectric Recovery Property Of Various Media
101
0
20
40
100 1000
SF6
10000
60
80
Vacuum
N2
H2
Time [micro-seconds]
Dielectricrecoveryvoltage[kV]

8. Interruption Principle
PUFFER TYPE:
 Involves compression of gas between a static piston and a moveable
cylinder during interruption action.
 Compressed gas is blown through nozzle in which arc is burning.
SELF EXTINGUISHING TYPE:
 Heat/ionization effect of arc causes gas pressure to increase in sealed arc
chambers.
 Over pressure causes turbulence in gas and forces it out as soon as nozzle
starts to open.
 This phenomena has strong effect on arc, making it thinner,
cooling, interrupting and providing rapid dielectric recovery

9. Puffer principle

10. Vacuum Interrupter
1 Stem / Terminal
2 Twist protection
3 Bellows
4 Interrupter lid
5 Shield
6 Ceramic insulator
7 Shield
8 Contacts
9 Terminal
10 Interrupter lid

11. Interruption Principles
SPIRAL CONTACTS
* To prevent overheating and contact
erosion, the arc is kept rotating
*The special geometry of the spiral
contacts generates a radial magnetic
field in all the areas of the arc column

12. Motor Switching with VCB
 ARC EXTINCTION AT CURRENT ZERO IS NOT POSSIBLE.
 (MIN +/-5A FOR ALL MANUFACTURERS)
 CURRENT CHOPPING IS IN EVITABLE FOR INDUCTIVE
LOADS
 I.E.SPECIFICALLY MOTORS WITH LOW LOAD
CURRENTS(e.g.NO LOAD)
 MOTOR HARMONICS GIVES RISE TO VIRTUAL CURRENT
CHOPPING
Better solution with SF6 CB

13. Capacitor Switching with VCB
 CAPACITOR SWITCHING AT LOWER CURRENT IS DIFFICULT WITH VCB
BECAUSE…..
 GAP BETWEEN MOVING CONTACT AND FIXED CONTACT IS VERY LESS
(8-10MM APPROX).CONTACT SPEED IS ALSO LOW (1M/S.APPROX)
 AT LOWER CAPACITTIVE CURRENTS, ARC EXTENGUISHES EARLY
WITH HIGH RESTRIKING VOLTAGE (VOLTAGE OF CAP IN ADDITION)
ACROSS CONTACTS WITH A GAP OF 2MM APPROX.
Result
 Multiple restrikes hinders smooth switching of capacitors
and capacitor as well as VCB contacts may damage
Better solution with SF6 CB

14. SF6 & VACUUM SWITCHING TECHNOLOGIES

SF6 CIRCUIT BREAKER VACUUM CIRCUIT BREAKER
 SF6 GAS PRESSURE MONITORING VACUUM CAN NOT BE MONITORED.
POSSIBLE.
 FALL IN PRESSURE CAN BE ANNUNCIATED. LOSS OF VACUUM WILL BE KNOWN WITH
 CB FAILURE.
 CAN INTERRUPT RATED CURRENT EVEN HAS TO BE TAKEN OUT FOR
 AFTER GAS PRESSURE FALLS DOWN TO REPLACEMENT OF POLES.
 ATMOSPHEREIC PRESSURE.
 GOOD ELECTRICAL ENDURANCE. GOOD ELECTRICAL ENDURANCE.
 INTERRUPTING CHAMBERS CAN BE INTERRUPTERS TO BE REPLACED (COST OF
 MAINTAINED. REPLACEMENT 40% OF CB ).
 SF6 BREAKER IS RUGGED. SENSETIVE TO ROUGH HANDLING.
 WELL SUITED TO MOTOR DUTY OPERATIONS RELATIVEY INFERIOR FOR MOTOR
 OVER VOLTAGE UNDER 2.5P.U. SWITCHING. SURGE PROTECTION ESSENTIA

15. WHAT IS IPXX

17. 11 KV BREAKER (HHV-12)
Contacts protected against
oxidation and contamination
 Vacuum interrupter embedded
in the resin poles
 Vacuum interrupter protected
against shocks, dust and
humidity
 Ensured operation under
different climatic conditions
 Limited switching energy
 High number of operations
 Operating mechanism with high
reliability

18. HHV-12 CUBICLE CROSS SECTIONAL DWG

19. EARTHING SWITCH

20. Outdoor Vacuum Circuit Breaker OFVP 36
 10000 operations at no load.
 10000 operations at rated current.
 Wide range of power supply
voltages of the electrical
accessories.
 Mechanical anti-pumping device to
prevent re-closing due to both
electrical and mechanical controls.
 Uses Hermetically sealed
interrupters.
 Cabinet mounted on Hot-Dip
Galvanised steel structure.
 Option to extend structure for
instrument transformers.

21. IMPROVE OUR BREAKER
 DOOR
INTERLOCK

22. ALWAYS THINK !!!!!!!!
 RIGHT POSITION

23. THANK YOU