Page 257 - Offshore Electrical Engineering Manual

244 CHAPTER 6 Calculation of Load Flow, Fault Currents

Asymm. (%)
Interrupting Duty (@ Contact Parting Time) Degree of DC Fault Symm. Asymm. Current (kA) kA Peak 117.85 3.016 2.559 3.517 140.81 3.022 2.146 3.382 133.82 2.996 2.239 3.388 58.93 7.188 12.198 58.93 7.446 12.635 58.93 7.358 12.485

Short Circuit Duty Summary Report Generator Circuit Breaker 3-Phase Fault Currents: (Prefault Voltage = 102% of the Bus Nominal Voltage) Momentary Duty (@ 1/2 Cycle) Symm. Asymm. kA rms kA rms kA Peak 1.809 6.803 1.518 6.396 1.583 6.458 11.228 8.625 23.444 11.631 8.935 24.280 11.492 8.828 24.003

Generator Circuit Breaker Evaluation per IEEE C37.013

Symm. Asymm. kA rms kA rms 4.575 1.853 4.472 1.558 4.463 1.628 14.155 8.660 14.660 8.969 14.492 8.867

Source and Generator PF Gen-lagging PF Gen-leading PF Gen-no load Sys-lagging PF Sys-leading PF Sys-no load

Circuit Breaker Type 5 cy Sym CB

ID CB4