Grounding question in regards to battery powered inverters.

[HANKMARS]

I desire to earth ground my 12V inverter in hopes of cleaning up its output waveform. Inverter is regarded as "pure sine wave" category, if I am remembering the terminology correctly. I realize "pure sine wave" is more of a category than a specification. It does have a pretty good looking output but tends to wander in performance due to reasons unknown to me. It seems logical that grounding could help stabilize output plus keep voltage from drifting to harmful potential. The inverter is rated at 1KW. My grounding plan is bare bones. Maybe a 12 gauge wire from ground hole in standard outlet, to 3 foot steel form pin driven 2 to 3 feet into Earth. What are my chances of improved performance?

 

[kellys_eye]

What are my chances of improved performance?

Depends. Is the output fully floating or referenced to ground (earth)?

Are you measuring under ideal load conditions? The spec for waveform distortion will be optimised for a specific load (I suspect).

Does the output vary under constant load? (not good - points to simple poor regulation in design).

What does the manual state re earthing? They are usually very 'vociferous' over such matters.

 

[HANKMARS]

Inverter output is fully floating. Waveforms 1A and 2A are what I was concerned about but after changing scope ground to inverter neutral, the waveform looks much more reasonable. Peak to peak of inverter seems a little thow. All shots take at 50V per division.

 

[kellys_eye]

Looks pretty clean to me - as for 'wandering' can you measure this? There is always a response time to changes in load so perhaps it's in the ballpark according to spec? Do you have the capability to test for transient response and/or comparing the output volts to spec according to load?

Either way, whether or not you earth the output depends on what you're plugging into and whether that has a neutral referenced ground (here in the UK the neutral is tied to ground). If you are worried for transients then fit a line filter with transient suppressors.