I prefer the 10Amp breakers on the postwar ZW for track power because they allow more operational flexibility, ie. more than one locomotive (conventional, LC, and/or Legacy) on a power district track a time with smoke and incandescent lit passenger cars.
In a more general sense of choosing a breaker's current rating, as long as the transformer's output current rating is not exceeded, any of the Instant breakers will trip immediately in the event of a derailment.
When TVS diodes are installed appropriately, I'm inclined to believe there's little benefit to choosing a smaller breaker for added train protection, if the selected instant breaker is rated approximately 20% less than the Postwar transformer's maximum output current. Thoughts?
