akjoseph_77 wrote:
I have to model a standby generator 200 KW and was given a fault current value from the manufacturer of around 7.6 kA. Can I just model a grid with this kA value and simulate the arc flash situation on emergency power? I am using ETAP.
Thanks!
For short circuit purposes, yes. Otherwise there are reasonable approximate values for the primary and secondary (X' and X'') that can be used for arc flash calculations where ETAP uses piecewise modelling to account for the long asymmetrical fault currents. This is always a tricky situation because the available fault current is usually about an order of magnitude less than utility fault current which greatly increases the overcurrent trip times and makes incident energy values much higher than during normal operation.