Originally Posted by
danielthechskid
A couple thoughts, PCs aren't nearly as sensitive to bad power as many think, the first thing most non or passive power factor corrected switched mode power supplies do with the power is run it through a bridge rectifier and into a large filter capacitor, or in the case of 115/230 switchable PC power supplies, when set to 115 it is 2 capacitors in series, 1 is charged by the positive peak of the wave, the other is charged by the negative peak. Active PFC is a different animal. Some active PFC controller ICs are just picky and won't even run on a modified sine inverter.
What is more important for SMPS is a proper wave peak voltage as that determines what the capacitors get charged up to, see what timebuilder posted. A non PFC unit only draws current when the instantaneous input voltage is higher than the DC rail voltage, hence why the current is drawn in pulses. The peak voltage of a pure sine is 1.414x the RMS so the SMPS expects the DC rail to be at 160-170 or 320-340v
These current pulses on a cheap generator with too high of a winding resistance cause the sine wave to become flat topped, thus reducing the peak voltage.
Also flame rectification microamp sensing furnaces require that the neutral and ground be bonded. My POS True Blue 90 runs just fine on my cheap Chinese 2 stroke ~1kw generator (the same one that is sold all over the place under various names and labeled from ~800-1200 watts).