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rbulsara, light sensors only is a possibility but not often used because of the practical downside (a flash from a camera can set them off). Most setups I've seen use an instantaneous overcurrent trip unit with a blocking function from the light sensor, ie the unit doesn't trip when no flash is...

The arc detection relays still have a certain pickup and fault clearing time. Take this together with circuit breaker operating time to calculate incident energy. To model this in Powertools or ETAP just create a custom relay with constant operating and clearing time over a large range (say...

Note that the empirically derived equations of IEEE Std 1584 are only valid up to 15 kV, above that the so-called Lee equations are used. These are theoretical values and can easily lead to incredibe incident energy levels and boundary distances (especially with the 2 second clearing times you...

Bolted fault calculation in IEEE 1584 actually doesn't specify ANSI. Powertools for example uses its 'comprehensive' method which is just solving a complex impedance network (and you can't force Powertools to use ANSI or IEC results). I don't know ANSI too well, but I know IEC 909's...

Just found this browsing the 'cablegate' site of wikileaks, about the 2009 Brazil blackout: http://cablegate.wikileaks.org/cable/2009/12/09BRASILIA1383.html Maybe there's not much news for those who followed this closely and there's some small technical errors ('50 Hz of DC power'), but I...

Are you sure the model of your cable includes shunt capacity? I know SKM Powertools default MV cable models don't include them, though I can't speak for ETAP. If you cannot modify it yourself, maybe add a pi impedance with the (hand calculated) values.