Grid tie behind the XW Pro?

[Turbonova]

Hello all, new here... Last year I installed a Solaredge Se10000 HD grid tie inverter with about 7kW of PV. That system lands in the main service panel on a 40a breaker. It works great. I've recently decided to add a separate system to take even more load off of the grid, and to use for power outages. Naturally I settled on the XW Pro. My utility won't let me sell back with the XW pro as it's NOT on the approved inverter list.... which is fine. I have no desire to sell with it, just self consumption. The XW has 2 mppt 60 150 charge controllers connected to about 6kW of PV. The XW's output feeds a sub panel I have installed. I have the XW setup for grid support and no selling. This way I run my sub panel off of the XW until the batteries reach about 51v. I've seen diagrams that show the grid tie inverter landing on the sub panel which would be on the XW inverter output. Makes sense for AC coupling, which I am not doing. In my setup, the grid tie lands on the main panel, which feeds AC in on the XW. I guess my question is, in the event of a grid failure, there's no chance that the XW can "form a grid" on it's AC in (which is where it sells power out to grid from what I understand), and turn the grid tie inverter back on, causing grid back feeding? It doesn't seem like it could to me, but I'd like to know if anyone else has a similar setup and can verify that. Any insight is appreciated. I can give more details if needed, thanks!

 

[BentleyJ]

In the present configuration the XW Pro cannot form a micro-grid because everything UPSTREAM of the XW AC Input gets cut off by the internal transfer relay in the XW which complies with anti-islanding rules.

XW has an option to use an external transfer switch instead of the internal one. If you installed a compatible transfer switch at the main panel between the meter and the main breaker. The system would disconnect from the grid at the main panel instead of at the subpanel and then inverter power could be delivered up stream from the inverter to the main panel without back-feeding the grid in an outage.

 

[Turbonova]

Okay, that's what i was thinking occurred. I'm guessing the XW won't allow any AC1 out action (selling) occur until it sees good AC input signal for 300 seconds? I was just concerned as I've not seen where people have set the inverter up this way with an additional PV inverter thats not AC coupled. I can't imagine I'm the only one that has it set up like this though either. I'm sure that's the first of many questions ill have. I'm still fine tuning all the settings to get it to behave how I'd like. Thanks for the help!