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|> > Look particularly at the "Maximum Output Fault Current" rating. |> > That's only 25 amps. Sure, this is a smaller inverter. But this |> > fault current is a mere 15.4 % more than the rated continuous VA |> > level. |> >
|> > So what happens if you do short circuit this thing on a 15 amp |> > branch circuit. Well, you won't have all that much of a fault |> > arc. But depending on where and how the fault happens, this |> > could actually be quite dangerous because it's not going to trip |> > a 15 amp breaker all that quick. |> >
|> > Is this common for inverters in the "natural energy market"? |> >
|> |> It will shut down pretty quick once the current exceeds its max |> electronic overload setting. These things are pretty cleaver. |> |> If you short the output it will probably just stop, sharpish. | | Are you sure about that? Where is that stated in the spec? If it feeds a | continuous 25A into a fault, that's a big problem (particularly since | that web page advertises a 30A overcurrent setting). | | A good design could easily incorporate a shutdown or foldback | regulation. But I didn't see that anywhere on the page.
If I put a transformer on a high available fault current AC system, such as a utility service drop, that is rated for my expected peak load, as calculated and planned, I can easily expect that under a secondary side short circuit fault condition that transformer can deliver a substantial amount of current, typically 20 to 30 times the maximum rating, for the typical 5% to 3% impedances I see. Even though the transformer could deliver such current, if there was no overcurrent protection and that fault persisted, you can expect the transformer to burn out soon (if not the wiring). I'm not expecting a transformer to be _rated_ for continuous duty at the same current level it could deliver very briefly in a fault. So if I connect an inverter to a set of batteries that can deliver a very high fault current, I would like to see the inverter be able to BRIEFLY deliver a very high current peak, even though if it were called upon to deliver that current continuously, and such a high current were not interrupted, I could expect the inverter to burn up.
I would want that high current briefly just to start motors. This is a common power system design aspect. I do know generators tend to have some problem with this as that requires substantial brief mechanical mover energy to provide.
One possible solution might be to supplement the inverter with large flywheel type system (motor/generator in the same windings) that can provide that "quick kick" when needed. But is this economical?
Another possibility is a separate inverter for each circuit. But I do suspect this is quite non-economical (for that cost you could have a big huge 100 kVA inverter that could deliver fault current to smaller branch circuit OCP).