How Big a Gen to Run a Converter? Some Info.

Note-I found out the " converter industry" uses the word "efficiency" to include the PF factor, so we don't have to think of efficiency and PF as two different things to apply to this problem.

I was skeptical of this, but before shooting my mouth off I did a couple of measurements with a WFCO 9855, convincing me the claim is not correct. AC readings are from a kill-a-watt, DC watts calculated as volts*amps:

9855 in normal mode-
DC volts 13.66, DC amps 39, DC watts 533
AC volts 119.4, AC amps 7.45, AC watts 636, AC volt-amps 896, pf 0.7
Crunching the numbers, efficiency in terms of watts is 83.8%, in terms of VA it's 59.5%. So if the "industry" statement were true, the efficiency is 59.5%.

Same test in boost mode:
DC volts 14.55, DC amps 41.2, DC watts 599
AC volts 119.2, AC amps 8.3, AC watts 706, AC volt-amps 992, pf 0.7
Crunching the numbers, efficiency in terms of watts is 84.8%, in terms of VA it's 60.4%. So according to the "industry" statement, the efficiency is 60.4%.

Using 60% as a round number, an eu2000i can power a 67 amp converter at 14.4 volts output, and an eu1000i can power 37.5 amps. I've made similar measurements on a PD9160 in the past with similar results.

The distortion power factor of the PF uncorrected converter varies with the AC input voltage and waveform. Logically, the PF is higher at lower AC voltages because the peak-to-rms current ratio improves. The mangled sine wave from a Microquiet generator results in a better PF than the fairly good sine wave from a Honda inverter generator or shore power. Here are some actual PF measurements with the 9855 heavily loaded:

124 volt sine wave: 0.68
104 volt sine wave: 0.80
120 volt RMS microquiet: 0.81

So talking about how much a particular generator can drive a converter without specifying the AC voltage and waveform is just as vague as specifying the correct charging voltage without specifying the temperature.