bjenks
Electrical
- Jul 14, 2006
- 68
I have a question about using the Point to Point Short Circuit Current calculations for three situations and need to know how to address them when calculating the "f" factor
1) For Line-to-Neutral Faults most articles assume that the neutral conductor and the line conductor are the same size. Most of the time that is not true, so I am wonder how the "f" factor would change for a smaller size neutral. Is making the neutral the same saze as the phase conductor giving me a higher fault current calculation and thus why it is not considered?
2) Does anything change when you have a 3 phase delta high leg? especially for the high leg?
3) Can I use the Ia= Is x Mp formula from the Asymmetrical Factor table to get I asymmetrical where Is is derived from the point to point method?
I don't use any fancy software or spreadsheets and need to come up with a system that is accurate enought, but not complicated.
1) For Line-to-Neutral Faults most articles assume that the neutral conductor and the line conductor are the same size. Most of the time that is not true, so I am wonder how the "f" factor would change for a smaller size neutral. Is making the neutral the same saze as the phase conductor giving me a higher fault current calculation and thus why it is not considered?
2) Does anything change when you have a 3 phase delta high leg? especially for the high leg?
3) Can I use the Ia= Is x Mp formula from the Asymmetrical Factor table to get I asymmetrical where Is is derived from the point to point method?
I don't use any fancy software or spreadsheets and need to come up with a system that is accurate enought, but not complicated.