Install to the output side of the EMS. Done right no need to check. Actually, I wired it right into the transfer switch.
The way I did it, and Escape does, is to isolate the convenience outlet feeds (2 of them unless you add another) to a separate small breaker box fed by a 30A feed through the transfer switch, where you also feed the inverter to. It will always feed through the AC pedestal unless the inverter is turned on, then automatically uses that for the feed.
2017 Escape 5.0 TA
2015 Ford F150 Lariat 3.5L EcoBoost
2009 Escape 19 (previous)
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