Aspen Breaker Rating Module

[breadboard]

In the Aspen Breaker Rating module there is an example for breaker and a half configurations (Section 3.3.3 in the instructions) where it states for the breakers attached to one of the buses they consider the possibility that the breaker might have to interrupt the total bus current. I don't see other than the case for a 2 bay breaker and a half and one bus breaker fails why this would be the case. Does anyone know the logic why they would be using the total bus fault current? Seems to me that would make your breakers come out underrated.

 

[davidbeach]

The two breakers may not open at precisely the same time, or one may have been out of service. The remaining breaker has to interrupt the contribution from all other sourced into the station.

 

[breadboard]

Ok thanks, that seems to make sense. I was thinking from the view that everything is ideal and timed perfectly.