A \(500-\mathrm{kV}\) three-phase transmission line has a \(2.2-\mathrm{kA}\) continuous current rating and a \(2.5-\mathrm{kA}\) maximum short-time overload rating, with a \(525-\mathrm{kV}\) maximum operating voltage. Maximum symmetrical fault current on the line is \(30 \mathrm{kA}\). Select a circuit breaker for this line from Table 7.10.

Table 7.10:-

Transcribed Image Text:

TABLE 7.10 Preferred ratings for outdoor circuit breakers (symmetrical current basis of rating) [10] (Application Guide for AC High-Voltage Rated Values Insulation Level Current Voltage Rated Withstand Identification Test Voltage Rated Rated Short- Nominal Circuit Breakers Rated on a Symmetrical Voltage Rated Max Nominal 3-Phase Voltage Rated Continuous Circuit Voltage Low Current at Range Fre- Impulse 60 Hz Current (at Rated Class MVA (KV. Factor Current Basis, ANSI (kV rms) Class rms) (K) quency (kV, rms) Crest) (KV. (Amperes, Max kV) rms) (kA, rms) C37.010 (New York: American National Coll Col 2 Col 3 Col 4 Col 5 Col 6 Col 7 Col 8 Standards Institute, 14.4 250 15.5 2.67 600 8.9 1972). 1972 IEEE) 14.4 500 15.5 1.29 1200 18 23 500 25.8 2.15 1200 11 34.5 1500 38 1.65 1200 22 46 1500 48.3 1.21 1200 17 69 2500 72.5 1.21 1200 19 115 121 1.0 1200 20 115 121 1.0 1600 40 115 121 1.0 2000 40 115 121 1.0 2000 63 115 121 1.0 3000 40 115 121 1.0 3000 63 138 145 1.0 1200 20 138 Not 145 1.0 1600 40 138 145 1.0 2000 40 138 145 1.0 2000 63 138 145 1.0 138 Applicable 145 1.0 138 145 1.0 138 145 1.0 161 169. 1.0 2000 80 3000 40 3000 63 3000 80 1200 16 161 169 1.0 1600 31.5 161 169 1.0 161 169 1.0 230 242 1.0 230 242 230 242 230 242 1.0 22 230 242 1.0 230 242 1.0 345 362 1.0 345 362 1.0 500 550 1.0 500 550 1.0 700 765 1,0 700 765 1.0 99999999999999 2000 40 2000 50 1600 31.5 1.0 2000 31.5 1.0 3000 31.5 2000 40 3000 40 3000 63 2000 40 3000 40 2000 40 3000 40 2000 40 3000 40