SOLUTION FOR THE WEAK LINK SOLUTION FOR THE WEAK LINK HIGH VOLTAGE BOLTED COUPLERS AND ADAPTORS SOLUTION FOR THE WEAK LINK SOLUTION FOR THE WEAK LINK HIGH VOLTAGE BOLTED COUPLERS AND ADAPTORS

HIGH VOLTAGE COUPLERS REGARDED AROUND THE WORLD AS THE WEAK LINK Couplers have been Failing in Service Failures were Unpredictable Cause of Failures Unknown Decrease in Safety and Health Decrease Production Increase Operation Costs WHY? ASSOCIATED PROBLEMS

ACARP REPORT ON THE FAILURE OF 11kV PLUGS AND ADAPTORS OF 11kV PLUGS AND ADAPTORS ACARP REPORT ON THE FAILURE OF 11kV PLUGS AND ADAPTORS OF 11kV PLUGS AND ADAPTORS Australian Mining Australian Mining Industry Concerned Industry Concerned Invested Through ACARP Invested Through ACARP

EXAMPLES OF FAILED COUPLERS IN SERVICE

CREATING DEAD SHORT SHORT

Australia South AfricaUSACanada 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

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”

DESIGN FLAWS FOUND

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 AIR AND PARTIAL DISCHARGE AIR PARTIAL DISCHARGE

SOLUTIONSSOLUTIONS Remove Air with Silicon Rubber Insert Insulating Material Developed to Extinguish Tracking Insulating Material Developed to Extinguish TrackingSiliconInsert InsulatingMaterial

NO TRIPS OR ANY SIGNS OF FAULT

PHASE SEGREGATION BY EARTH PHASE Mining Industry Standard EARTH

A Phase to Ground Fault was created with conductive paint Earth Star Placed Between Phases A Through Fault Test was then performed on this solution to see how it would perform in the field FIRST SOLUTION

REASON FOR FAILURE PHASE 1 EARTH PHASE 2 PHASE 3

FINDING A SUCCESSFUL SOLUTION. Equipotential Lines Good Earth Star Equipotential Lines Crushed Up Individually Screened Cable Equipotential Lines Good

SOLUTIONSOLUTION New Design expels all air in face of coupler and phases are segregated by ground SEPARATEINSULATORS BODY SEGREGATES PHASES EXPELS ALL AIR

ALL TYPE TESTS PERFORMED WERE WITHIN CABLE SPECIFICATIONS ALL TYPE TESTS PERFORMED WERE WITHIN CABLE SPECIFICATIONS COUPLERS HOMOGENEOUS WITH CABLE EARTH

COMPARISONCOMPARISON

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. “

PEACE OF MIND ANALYZING THE DESIGN ADVANTAGES Increased Safety Increased Reliability Increased Reliability Increased Productivity Increased Productivity Increased Security Increased Security