3000W Chinese Gensets Info.

professor95 wrote:

toprudder wrote:

I will be pulling my camper next weekend and will be pulling it by where I work, so I may hook it up to a power analyzer to take a look at it. You've got my curiosity up. :)

.... and mine too. I hope you are able to run the test and will share your findings. The only power analyzer I have is a 60 watt incandescent light bulb or two wet fingers.

OK, was able to stop by work on the way back from a trip, and hooked up the camper to a power analyzer. I turned off all breakers except for the converter. Since I had run the generator most of the morning, and then had the camper connected to the tow vehicle on the way back, the camper battery (a single G24) should have been fully charged. In order to load the converter more, I turned on all the lights in the camper.

The power analyzer system includes a solid state power source. Think of a powerful sine-wave inverter, but this one is powered by 208v three phase. There is also instrumentation to measure voltage and current waveforms and harmonics. We use this system to test products for compliance to (mostly) European requirements.

Here are the voltage/current waveforms:


As I suspected earlier, the current waveform is terrible. Current only flows when the voltage is near the peak. Also notice the amount of peak current, over 20 amps!

Here is the harmonic summary:

The European limits were used, but tested at 120v (European power is 230v, between phase and neutral). The WFCO converter failed the limits miserably.

The software for the analyzer also checks the voltage waveform to make sure it meets the requirements for the test standard. In this case, it failed. This is the first time I have ever tested anything that the voltage waveform requirement failed. I can only guess that the current waveform from the converter was so bad that it was distorting the voltage waveform from the power source.

Professor, given the output impedance of a generator, I'm not surprised you saw the chopped-off waveform that you did.

Now I wish I had a different brand (Iota or Progressive Dynamics) to test.