From the Bussman.com website:
http://www.bussmann.com/library/techspec/TechSpec12.pdf Up-Over-Down Method:
With series rated combinations, the up-over-down method is not able to be used to determine the protection of newer
style circuit breakers with blow-apart contacts (which exhibit dynamic impedance). For these applications, listed
equipment which has been labeled for use with tested combinations must be installed. Despite the inability to predict
protection for circuit breakers using the up-over-down method, the method is still (as it always has been) valid for
static components (components passive within first half-cycle). Some applications which can utilize the up-overdown
method include:
1. Bus-Bracing Requirements
2. Wire and Cable Protection
Poster's note: It appears that a portion of equipment withstand ratings can use this chart method.
