earth leakage protection in 240 volt AC inverters

[jonovid]

I got given a box of old electronics.  in the box was two cheap input 12volt DC to 240 volt AC output inverters.
the 300watt  type used for camping or outdoors.  not tested then yet.
I am getting second opinion before running one. 
what personnel protection do we have?  is it floating 240 volt AC. 
before I start poking around inside one.
what is the case here 

[james_s]

They're very simple. They consist of a boost converter that generates ~340VDC which feeds an H-bridge that turns it into an AC square wave with dead time, aka "modified sine wave". The battery powering them is itself a floating source so obviously the output of the inverter will be a floating source unless you earth it.

Just plug it in and connect a lightbulb or something to the output to see if it works, they're probably fine. Usually when they do fail the problem is some bad mosfets.