Rectifier voltage drop under load
358Vac pk No load x 0.707 = 253Vac rms if it is a sine.
3000W at 240V @ 12.6A @ ~20 Ohms linear load



  The engine on the generator is capable of sustaining a continuous 3kw load.  


This is where people make false assumptions.  This only applies to linear loads and a bridge cap is a short circuit of about 0.1 to 1 Ohm not 20 Ohms.

It all comes down to impedance ratio of load/source.  For a linear PFC it needs to be a high R Load/Source ratio.  Batteries and caps are very low impedance with pulsed current.


  Solution : Active PFC.