I was reading an interesting document made by S&C about the calculation of a transformer inrush current based on the impedance and the short-circuit available at the primary side of the transformer:
We usually use a 8 to 12x nominal value for 0.1s to estimate the inrush current, but I saw many transformer protection curves adjusted way below this level, but still allowing energization without any problem. I was wondering how we could have a better estimation of this inrush current instead of the usual 12x.
Do you know any other documents from official organization like IEEE or standards about this calculation?
We usually use a 8 to 12x nominal value for 0.1s to estimate the inrush current, but I saw many transformer protection curves adjusted way below this level, but still allowing energization without any problem. I was wondering how we could have a better estimation of this inrush current instead of the usual 12x.
Do you know any other documents from official organization like IEEE or standards about this calculation?