Chinese inverter + charging same time?

[df00z]

I have one of those chinese UPower split phase 18000w pure sine wave inverters. It'll do 3000w all day. I notice as you load it, the 60hz noise gets louder from the transformer vibrating.

If I load it and run a separate 100a charger though, I am noticing an irregular pulsing of transformer noise. I haven't plugged an oscilloscope on it while it is doing it. Is it because of harmonic interference? Likely the charger is just a switching dc power supply running at 100-300khz. Can it cause harm?

 

[df00z]

The waveform actually looks better while it is plugged in and under load, the sin wave is more rounded. My bat is at like 50%. The load is resistive, a 400w heating panel turning on and off maintaining temp. The inverter's output voltage is higher when on bat charger, so maybe it's just doing more work so more vibration

I have one of those chinese UPower split phase 18000w pure sine wave inverters. It'll do 3000w all day. I notice as you load it, the 60hz noise gets louder from the transformer vibrating.

If I load it and run a separate 100a charger though, I am noticing an irregular pulsing of transformer noise. I haven't plugged an oscilloscope on it while it is doing it. Is it because of harmonic interference? Likely the charger is just a switching dc power supply running at 100-300khz. Can it cause harm?

. It's probably all reasonable for what it costed and probably is fine?

 

[solar8484]

That UPower is a rebranded PowerJack which is notorious for vastly overrated power capacity. The noisy waveform is due to poor filtering and regulation. Overloading is a likely cause of the humming and flat top waveform under load. PowerJack typically overrates power capacity by ~4x but UPower took it to another level. The 18000W inverter can likely only safely handle ~2500W continuous.