D—4

GRAPHICAL ILLUSTRATION OF FOREGOING TABLE

2. Reliability of Supply There were 163 faults, 61 of which caused no interruption to supply. The following analysis does not include prearranged shut-downs.

14

Year Ended 31st March, 1950. Year Ended Description., 31st March, 1949. Number. Duration. h. m. 1. 110 kV. lines : Defects 15 1 1 26 2. 110 kV. lines : External causes 17 15 3 25 3. 33 kV., 50 kV., or 66 kV. lines : Defects 17 10 55 32 4. 33 kV., 50 kV., or 66 kV. lines : External causes 5 5 3 26 5. 6-6 kV. or 11 kV. lines : Defects 5 2 4 20 6. 6-6 kV. or 11 kV. lines : External causes 1 1 1 08 7. Lightning 72 17 3 45 8. Storms : Nature of trouble not found 1 0 28 9. 110 kV. apparatus 2 4 2 56 10. 33 kV., 50 kV., or 66 kV. apparatus 6 5 5 15 11. 5 kV., 6-6 kV., 11 kV., or 22 kV. apparatus 8 13 19* 41 12. Generators or synchronous condensers 5 9 51 13. Relays 5 5 2 09 14. Control circuits and batteries 7 0 31 15. Operation: Mistakes io 12 2 09 16. Operation : Accidents 9 8 0 21 17. Faults and overloads on consumers' system 18. Other causes .. .; si 22 13 10 19. Cause unknown 20 30 3 05 Totals 223 163 132 38