11.2 X1 (50) (This problem is not in the book, see Ex.11.2, p. 651 for a similar problem) A distribution feeder has the following characteristics: loh = overhead circuit length: 4 miles lug = underground circuit length: 6 miles Number of cable terminations: 2 Length of recording of failure: 15 years Recorded number of faults in 15 years: ug, 2 faults per 15 years, per circuit mile oh: 5 faults per 15 years, per circuit mile cable termination fault rate: 0.4% per year per termination average repair times are 5h (for oh), 38h (for ug), and 6h per cable termination. Determine: a. the total annual fault rate of the feeder b. annual fault restoration time of the feeder in hours Answers: (a) 2fdr = 2.14 feeder faults per year, where afdr is the failure rate of the feeder 2oh = 1,33 aug = 0.8 Act = .008 (b) Average annual restoration time of the feeder PFDR = 209.96 hours 11.2 X2 (50) Solve problem 11.2 X1 for: a) Unavailability of the feeder b) Availability of the feeder 11.2 X1 (50) (This problem is not in the book, see Ex.11.2, p. 651 for a similar problem) A distribution feeder has the following characteristics: loh = overhead circuit length: 4 miles lug = underground circuit length: 6 miles Number of cable terminations: 2 Length of recording of failure: 15 years Recorded number of faults in 15 years: ug, 2 faults per 15 years, per circuit mile oh: 5 faults per 15 years, per circuit mile cable termination fault rate: 0.4% per year per termination average repair times are 5h (for oh), 38h (for ug), and 6h per cable termination. Determine: a. the total annual fault rate of the feeder b. annual fault restoration time of the feeder in hours Answers: (a) 2fdr = 2.14 feeder faults per year, where afdr is the failure rate of the feeder 2oh = 1,33 aug = 0.8 Act = .008 (b) Average annual restoration time of the feeder PFDR = 209.96 hours 11.2 X2 (50) Solve problem 11.2 X1 for: a) Unavailability of the feeder b) Availability of the feeder