EHV SWITCHGEAR

INTRODUCTION

CATEGORIES:

LV SWITCHGEAR

230 VOLT 415 VOLT

MV SWITCHGEAR

3.3 KV 6.6 KV 11-15 KV 33 KV

HV/ EHV SWITCHGEAR

66 KV 110 KV 132 KV 220 KV 400 KV AND ABOVE

SWITCHGEAR COMPONENTS

BREAKER MEASURING EQUIPMENTS CT PT / VT/ CVT ISOLATOR / DISCONNECTOR LIGHTNING ARRESTOR

Circuit Breaker Developmentthe sixtiesthe seventies & the eightiesthe eighties & the nineties

What is a circuit breaker?Device to open/close electric circuit

Ideal conductor in closed position

Ideal insulator in open position

Main Part of Circuit BreakerBreaking element(s)Breaking chamber, interrupter chamber, interrupter housing, etc.Contains interrupter, interrupting mediumSupport insulatorLine-to-ground insulatorContains insulated pull-rod, insulating mediumOperating mechanismStored energy, secondary wiring

Live Tank vs. Dead Tank Circuit BreakersDead TankLive Tank

BREAKER

TYPE: OCB FIRST INVENTION EARLY 50 USE OF OIL IN BULK QUANTITY BIG IN SIZE HAZARDOUS/EXPLOSION/FIRE-DAMAGE TO SURROUNDING EQUIPMENT MOCB BETTER DESIGN-REDUCE OIL QTY AND SIZE LESS HAZARDOUS ABCB USE OF COMPRESSED AIR NO FIRE HAZARD PROBLEMS IN MONSOON ADDITIONAL AUXILIARIES - COMPRESSORS PIPING ETC.

BREAKER (OCB)

GAS USE OF SF6 GAS NO FIRE HAZARD VERY COMPACT IN SIZE SIMPLE MECHANISM DUE TO LESS CONTACT TRAVEL VACUUM 100% VACUUM NOT POSSIBLE COULD DEVELOP UPTO 66/110 KV BREAKER EXPERIMENTS ARE GOING ON. COMMERCIAL PRODUCTION YET TO START

BREAKER

BREAKER (SF-6)

CURRENT TRANSFORMER (CT)

DESIGN :

LIVE TANK SECONDARY CORE AT PRIMARY TERMINAL SIMPLE IN DESIGN ANY OIL LEAKAGE MAY LEAD TO FAILURE

DEAD TANK SECONDARY AT BOTTOM PRIMARY LEAD TO BE EXTENDED UP TO BOTTOM LITTLE SPECIAL DESIGN

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