You say you bench tested at a higher (135Vac) voltage, but what about a lower voltage? Fuses open due to high current, not high voltage. For a given amount of power, one would expect higher current requirements when the voltage drops.
Is your UPS system regulating output voltage well?
A...
I've had some experience with Fireball 24Vdc strobes. It was discovered that the manufacturer actually makes two models - a "regular" model and a low-inrush model. We were having problems with inrush and had to switch to the low-inrush model.
On your model, is the fusing...
