"- tripping of short-circuit protection (magnetic tripping device): if the current exceeds the threshold of this protection device, the breaking time is less than 10 milliseconds
For short-circuit currents exceeding 20 times the rated current, the time-current curves do not give a sufficiently precise representation. The breaking of high short circuit currents is characterized by the current limiting curves, in peak current and in
energy. The total breaking time can be estimated at 5 times the value of the ratio (I2t)/(Î)2. Verification of the discrimination between two circuit breakers"
What is the reason for estimating the total breaking time with a 5x multiplier of the ration between (I2t)/(Î)2
Does (Î) = the limited peak current (assuming current limiting of upstream protective devices) or is this meant to be peak current?
Is it possible to calculate that the first half cycle rise in current, will cause the MCB to trip by pushing the circuit breaker to a point of no return in respect to the opening of contacts (where it will not reclose).