Managing SF6 gas leaks in Circuit Breakers - Dilo

1 DILO 2nd Annual SF6 Gas management Seminar Tampa FL, November 2017. Zero Emissions. No Substitutes. Managing SF6 gas leaks in Circuit Breakers The true art of SF6 gas leak detection and leak seal November 15, 2017. Steve Wickman, PE electric utility independent consultant John Edmon TDS-Transmission & Distribution Services - Our story for you today SF6 what is it? Why SF6 in electric utility apparatus? Some history SF6 good stuff SF6 bad stuff SF6 leaks find them and fix them Steve s experiences with SF6 CBs January 2013 Page 2.

2 Is it? Sulfur Hexafluoride Sulfur hexafluoride (SF6). is an inorganic, colorless, odorless, non-flammable, extremely potent greenhouse gas, which is an excellent electrical insulator. SF6 has an octahedral geometry, consisting of six fluorine atoms attached to a central sulfur atom. January 2013 Page 3. Why SF6 in electric utility apparatus? Some history January 2013 Page 4. Why SF6 in electric utility apparatus? Some history January 2013 Page 5. In the early 1950s high-voltage CBs of bulk oil configurations were becoming the norm These OCBs had an exemplary record but the possibility of failure, and the risk of explosion and oil fires existed Systems grew & HV OCBs were located increasingly in urban areas and the consequences of OCB failure gained importance January 2013 Page 6.

3 In the early 1950s the New York Consolidated Edison Company (Con Edison) in particular started to push for an oil-less breaker design In response to this oil-less breaker need, the Westinghouse Electric Company initiated a program to develop the GCB using SF6 as the insulating dielectric & interrupting medium, transforming the breaker industry Thirty years later every manufacturer of H-V. Breakers adoped SF6 as the medium of choice January 2013 Page 7. Early Installations PP&L 230kV GCB at Brunner Island substation the first SF6 CB.

4 Placed in commercial service January 2013 Page 8. Early Installations ConEdison Hellgate substation May 1960 first two installed SF6 GCBs 138kV 10,000 MVA. ConEdison GCB failure February 1961, previous experience with oil CBs indicated that total or near total destruction occurred This SF6 CB failure was repaired & the CB restored in two days and subsequently ConEdison placed their first substantial order for 138kV SF6 CBs January 2013 Page 9. SF6. The good Higher dielectric strength than air or nitrogen Provides for compactness in the design of equipment The bad Found to be the most potent greenhouse gas known to date Emitted into the atmosphere it accumulates in an undegraded state for centuries January 2013 Page 10.

5 SF6. Bottom Allowing it to leak freely into the atmosphere is not a good thing US EPA Develop SF6 emissions reduction strategies Inventory of SF6 using eqiupment Estimate current emissions January 2013 Page 11. SF6 got leaks ? SF6 leaks find them and fix them January 2013 Page 12. SF6 Leak Detection January 2013 Page 13. SF6 Leak Detection January 2013 Page 14. SF6 Leak Detection January 2013 Page 15. SF6 Leak Survey & Sketch January 2013 Page 16. Leak Repair Technique on SF6. Apparatus External clamp January 2013 Page 17.

6 External clamp January 2013 Page 18. External clamp January 2013 Page 19. External clamp January 2013 Page 20. External clamp January 2013 Page 21. External clamp January 2013 Page 22. External clamp January 2013 Page 23. External clamp January 2013 Page 24. External clamp January 2013 Page 25. External clamp January 2013 Page 26. External clamp January 2013 Page 27. External clamp January 2013 Page 28. External clamp January 2013 Page 29. External clamp January 2013 Page 30. External clamp January 2013 Page 31.

7 Clamp repair concept drawing January 2013 Page 32. External clamp January 2013 Page 33. External clamp January 2013 Page 34. SF6 piping leaks in GCB control cabinet January 2013 Page 35. SF6 piping leaks typical measurements January 2013 Page 36. SF6 piping leaks January 2013 Page 37. SF6 piping leaks January 2013 Page 38. GIS leaks January 2013 Page 39. GIS leaks January 2013 Page 40. SF6 leaks -find them and fix them Initial leak detection can be performed with CB in service Detailed survey and measurements without disassembly of CB.

8 Clamp design and fabrication performed in a day or two and air freighted to the worksite Repairs completed in a day or two with minimal outage time and NO degassing of the CB on customer safety/work practice requirements January 2013 Page 41. SF6 leak a case study Steve s actual experience ~1980. Westinghouse SFA GCBs 765kV. January 2013 Page 42. SF6 leak a case study January 2013 Page 43. SF6 leak a case study January 2013 Page 44. SF6 leak a case study WWJD? January 2013 Page 45. SF6 leak a case study What Would Jesus Do?

9 What Would Jesus Drive? What Would Judas Do? We Want Jack Daniels January 2013 Page 46. SF6 leak a case study What Would John Do!!! January 2013 Page 47. SF6 leak a case study January 2013 Page 48. SF6 leak a case study January 2013 Page 49. SF6 leak a case study January 2013 Page 50. SF6 leak a case study January 2013 Page 51. SF6 leak a case study January 2013 Page 52. TRANSMISSION & DISTRIBUTION SERVICES, LLC. 28369 DAVIS PARKWAY, SUITE 401. WARRENVILLE, IL 60555. P F Steve Wickman John Edmon January 2013 Page 53.

10 John Edmon John Edmon 44 years in the Leak Sealing business starting out working for leak seal firms working in the petrochemical and electric power house industry. In 1988, upon the suggestion of an Electric Utility equipment specialists John worked with at a power plant on the west coast of the USA, he developed his technique for sealing low pressure leaks , initially in large power transformers. The techniques then flowed over to CBs initially oil CBs. As the SF6 dielectric medium became more prevalent in CBs in the industry, John started applying the same techniques to SF6 gas apparatus.