Dave, from the point the a/c leaves the inverter every thing is the same as an on the grid house.What would you do to isolate a circuit in a regular house?.
Mike
Mike, circuit isolation in a normal system consists of a homerun back to the point of origin, i.e., the circuitbreaker panel.service entrance. This includes the ground. Circuits should never rely upon the EMT/box combination to provide the safety ground. Corrosion can interrupt the ground. I assume that you are not using EMT and are wired with Romex or equivalent.
The big question that I have is the power quality from the inverter. Some are incredibly dirty when it comes to switching noise and harmonic content. What type and brand are you using?
Local isolation can be done in several ways. You can use isolation transformers which are really good IF they are adequate in current capability. I have a Topaz 2.5KVA that feeds my electronics on a dedicated 20A circuit. The Topaz is over spec in this application which is fine by me.
Another way is to use local power regeneration like the PS Audio units. I have used them in the past and found them pretty darned good.
My BUSS Series does an excellent job in providing local clean power, too (insert shameless plug here). What you should not rely upon are the small "power conditioners". These are pitifully inadequate in operation.
Something that works pretty well for digital front ends and sources are small 3A isolation transformers. They effectively keep digital nasties from being fed back down the power cable into the lines. They usually have 'E' core transformers with limited bandwidths and provide excellent lineborne isolation.
What else? My brain hurts right now.
RMAF is kicking my butt already and I'm just in preparations.
Dave