How to calculate the breaking capacity(like 15ka,20ka) of
Circuit breaker (MCB,MCCB,ACB)

Answer Posted / hrusikesh dehury

we must know load of perticular equipment.
For Ex. Our load in MVA is 50 MVA
Our system voltage(MCB,MCCB,ACB) is 440V.

I(Bre)= 50/(1.73x0.440)=65.6 =Approx 65KA.

Our load in MVA is 20 MVA
Our system voltage(MCB,MCCB,ACB) is 440V.

I(Bre)= 20/(1.73x0.440)=26.2 =Approx 25KA.

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