SoundGuy wrote:
otrfun wrote:
Are there any confirmed failures caused by using a PSW inverter or inverter generator with a PI EMS?
Page 3 of the Progressive Industries EMS-HW30C / EMS-HW50C owner's manual says to NEVER plug their EMS into an inverter. As far as a generator is concerned - yes, there's that Yamaha EF2000iS warranty disclaimer from Progressive that ought to be sufficient proof that this is also a real concern.
Since modified sine wave has been identified by Progressive as the death knell for any of their EMS units it stands to reason that modified sine wave produced by any source, be it a generator or an inverter, is to be avoided when using one of their EMS units. However, assuming the inverter in question produces pure sine wave one would think it wouldn't be any different than an inverter generator producing pure sine wave BUT there is a caveat - not all inverter designs are the same. Some are designed with a 60/60 centre bonded neutral output, in which case one can't add a neutral / ground bond, so it's not just a simple matter of trying it to see if it works, you first have to know the specifics of the particular inverter you want to use with your EMS.
Yeah, I saw that warning, too. That why I called PI like everyone else to get a clarification. I just happened to get the owner on the line. He was covering for his tech for lunch. He admitted the inverter warning was probably applicable to MSW inverters, but wasn't absolutely sure. He told me "not to worry', to go ahead and try my PSW inverter and inverter generator to see what would happen. If it toasted he promised me an overnight replacement--lol! No drama ensued---worked fine.
Pretty surprising to hear the Yamaha EF2000iS' output degrades that badly. There is a pretty significant difference between a modified sine wave and pure sine wave. Even my wife was surprised at how "nasty" a MSW looks on a scope.
In any case, I've seen more deviation in some commercial power waveforms then I've observed in my PSW inverter or Champion inverter generator when under no/full load. The only time there's any issue is when the Champion ramps up to start an inductive load. The waveform does distort to a somewhat sawtooth shape for about 250ms.
I realize not everyone has access to a scope to verify waveform quality. But, if I was playin' the odds game, I'd venture to say the vast, vast majority of PSW inverters and inverter generators would pose no issue to the PI EMS.
