[RE-wrenches] Outback AC coupling Sunpower?

[Ray Walters]

Hi All;

I know AC coupled systems have been covered before, but I have a new 
issue:  positive grounding.  A customer with an existing 8kw Sunpower 
system wants to add backup.   He was put off by the high cost the Sunny 
Island, so I was steering him towards a single Outback VFX coupled to 
just one of his 3 inverters.  The issue is how will the VFX work with 
positive grounded inverters.  I'm assuming that since the two inverters 
will only be connected by AC, that the positive vs negative grounding of 
their separate DC systems will not matter.  Any experience with this 
particular scenario: Sunpower system AC coupled to an Outback?
Also, would I even need a GVFX, since the inverter would only be used 
during outages  (which might allow a generator to be used later as 
well)  A VFX should still AC couple to the GT inverter during an outage, 
right?

Thanks as always,

-- 
R.Ray Walters
CTO, Solarray, Inc
Nabcep Certified PV Installer,
Licensed Master Electrician
Solar Design Engineer
303 505-8760