Thanks, i recetly spent quite a decent number of hours investigating the overall cost and availability of AC vs DC fuses (on digikey , mouser etc etc) for this use on the 400VDC Boost PFC output rail.........overall........AC fuses were cheaper and significantly far more "in-stock" than DC fuses. As such, we want to get into using AC fuses if its do-able.
I must admit here that we are fusing a prototype 2kW offline SMPS. In particular we will fuse the 400VDC output bus of the Boost PFC stage.
AYK, this is DC....but AYK, fusing of this rail is not mandated by regulations......the only fuse required by regs in an offline PSU is the AC fuse in the mains AC input.
No other fuses are required.
...As such, why should we, in this prototype, use a more expensive DC fuse in the 400VDC rail, when even regs dont mandate a fuse in there at all?
My apologies , but i should have explained, this is a free-of-charge prototype for a group of engineers.....if they like it, they will pay me to do the thing properly and fully, for now, all they want is to see 180V at 2kW (into a dummy load) and they're happy.
The mosy likely event, is that they will look at the prototype, and even if it works, they will just get their Chinese partners to do it anyway....or take the PSU on themselves and do it themselves.......so i deffo dont want to spend a penny or cent more on this thing than i have to......there is no payment whatsoever to the demo'd working prototype stage.
If i mis-assemble something and it blows up, then if its more fused, less stuff will need replacing...thats the hope.