Steven
Questions:1
Answers:42
Best Answers:12

The breaking capacity is normally specified by the manufacturer. To have this rating verified the breaker had to undergo a series of tests. There is also a post on the site which you can look at:

http://myelectrical.com/opinion/entryid/101/understanding-lv-circuit-breaker-fault-ratings

If you want to know which breaker rating to select, you need to calculate the anticipated fault level and then select the next highest rating. IEC 60909 gives guidance on how to go about calculating the anticipated fault level (and there are other methods/tutorials around if you search for them).

trex
Questions:2
Answers:6
Best Answers:0

we cant able to calculate breaking capacity of breaker due to is deponds of the breaker manufacturing as per iec rules ... it is the with stand capacity of the breaker ,, there is only the chance to calculate breaker withstand capacity by interms of transformer MVA rating....