How Big a Gen to Run a Converter? Some Info.
EDIT: some of my earlier posts in this thread have the wrong idea. As more info came in later, things got less confusing--sort of! :) --------------------- Another look at this topic. It is n...
Forum Discussion
BFL13 wrote:
I tried to be careful in my wording, but may have slipped here and there. I meant to say that "industry" includes PF in the "efficiency" NOT that PF and efficiency are the same.
I don't know how they can tell if they do, how much of the difference between power in and power out is due to PF and how much is due to heat loss, conversion loss, or whatever. I thought that power difference was how they calculate PF, so I find it all very confusing!
Bottom line IMO is that the gen needs to supply enough VA as "power input" to run the converter at its "max power output"
The various spec sheets from the various Brands are less than helpful about just what it does take to run their converters. At least we can help ourselves by starting with the easily calculated "power out"
Then you can pull an "efficiency" number out of your hat, and get the "power in" figure to compare with the generator's specified continuous VA. You don't know how much "margin" the gen gives you, and that would vary with altitude etc too, so yes, go big.
typically power efficiency is power in/ power out. So in that sense the published data is reasonable. and input power is not V*A in this case it V*A*PF.
But what it really boils down to is that in your sticks and bricks house PF is normally not an issue. The power source can delivery all the current you need, essencially an infinite voltage source.
However, for us with Generators, PF IS a BIG issue when determining what can really be run off a generator. IMHO mfg need to spec the VA rating on consuming devices and generator mfg need to drop the "Watts" rating and spec VA more conspiciously. Honda does spec the generators in VA terms, but only in the detail in the manual. the adds talk about "Watts" and don't educate users on what VA is and how it affects generator use.
Granted many generator users are driving close to resistive loads, most power tools, even an AC has a PF close enough to 1 to not be an issue. But microwaves and converters are terrible.
And I wish more converter mfg would do PF correction like one mfg does on the higher output devices.
End of soapbox!
