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SOLUTION FOR THE WEAK LINK HIGH VOLTAGE BOLTED COUPLERS AND ADAPTORS. HIGH VOLTAGE COUPLERS REGARDED AROUND THE WORLD AS THE WEAK LINK. WHY?. Couplers have been Failing in Service Failures were Unpredictable Cause of Failures Unknown. ASSOCIATED PROBLEMS. Decrease in Safety and Health
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SOLUTION FOR THE WEAK LINK HIGH VOLTAGE BOLTED COUPLERS AND ADAPTORS
HIGH VOLTAGE COUPLERS REGARDED AROUND THE WORLD AS THE WEAK LINK WHY? • Couplers have been Failing in Service • Failures were Unpredictable • Cause of Failures Unknown ASSOCIATED PROBLEMS • Decrease in Safety and Health • Decrease Production • Increase Operation Costs
ACARP REPORT ON THE FAILURE OF 11kV PLUGS AND ADAPTORS • Australian Mining • Industry Concerned • Invested Through ACARP
1 2 3 5 6 4 EXAMPLES OF FAILED COUPLERS IN SERVICE
SHORT CREATING DEAD SHORT
RESEARCHING COUPLERS GLOBELY Research showed that all the designs were very similar. These similarities were: • Insulators were all of a tower design • When closed, all suffered from air being trapped around the • insulator profile • The same design flaws were present in all types of couplers USA Canada Australia South Africa
ACARP PROJECT C5032 Research into the Failure of 11kV Plugs and Adaptors used in Underground Coal Mines Quote: Executive Summary: “A number of design weaknesses were identified that lead to the generation of partial discharges within the assembled plug and adaptor”
AIR AIR AND PARTIAL DISCHARGE • Large Volume Of Air Trapped Inside Coupler Enclosure • High Discharge Creates Corona • Corona Converts Air To Ozone • Ozone Is A Conductor • Phase To Phase Flashover PARTIAL DISCHARGE
Insulating Material Silicon Insert SOLUTIONS • Insulating Material Developed to Extinguish Tracking • Remove Air with Silicon Rubber Insert
EARTH PHASE EARTH PHASE EARTH PHASE EARTH PHASE SEGREGATION BY EARTH Mining Industry Standard
A Phase to Ground Fault was created with conductive paint Earth Star Placed Between Phases FIRST SOLUTION A Through Fault Test was then performed on this solution to see how it would perform in the field
PHASE 1 EARTH PHASE 2 PHASE 3 REASON FOR FAILURE
Equipotential Lines Good Earth Star Equipotential Lines Good Equipotential Lines Crushed Up Individually Screened Cable FINDING A SUCCESSFUL SOLUTION .
EXPELS ALL AIR BODY SEGREGATES PHASES SEPARATE INSULATORS SOLUTION New Design expels all air in face of coupler and phases are segregated by ground
EARTH ALL TYPE TESTS PERFORMED WERE WITHIN CABLE SPECIFICATIONS COUPLERS HOMOGENEOUS WITH CABLE
ACARP PROJECT C5032 Research into the Failure of 11kV Plugs and Adaptors used in Underground Coal Mines Quote : NEW DESIGN “Given the nature of the new design and the high voltage stress management issues that it addresses, it is expected that other manufacturers will follow this lead and produce their own variations of the design. “
ANALYZING THE DESIGN ADVANTAGES PEACE OF MIND Increased Safety Increased Reliability Increased Productivity Increased Security