Conxt SW Inverter does not like Sunnyboy.

pcrover said:

When I connect the Conext SW inverter to the AC line a relay inside the unit starts chattering. Nothing will make it stop until I turn off the Sunnyboy then the SW inverter stops chattering. While chattering it does not give any fault codes or other indication that there is a problem, just a chattering relay.

Has anyone seen this type of problem?

Yes, this is what happens when the AC coupled power has nowhere to go (my situation when i experienced it) and possibly other states.  And, because there are many bugs in the AC Coupling firmware, the SW does not always attempt to frequency shift or perform a RSD.  The latter happens when the modbus address "1039=AC Coupling" setting is switched off or ignored (i am working with Schneider trying to get this fixed!).

Your Sunnyboy should be feeding the SW "AC Out" connections.
The AC Coupled Smart Charge feature is supposed to direct the power to first charge the batteries and when fully charged, pass the power thru to the grid.
If the batteries are charged and the SW is not connected to a grid (or grid down), the the SW is supposed to frequency shift so the Sunnyboy slows or stops AC production.  Failing that, the RSD is supposed to stop AC production.

But the numerous bugs in the current firmware don't handle all these scenarios and can cause catastrophic failure (Schneider won't elaborate what eventually happens, i suspect that means house fire).

The Conext SW line clearly fails the UL 1741 and UL 1741SB certification requirements.