I have no idea why SquareD doesn't include this cheap part with their subpanel boxes, but it is a...
May 17, 2020
I have no idea why SquareD doesn't include this cheap part with their subpanel boxes, but it is an essential component, required by code. I discovered this when I tried to install a combined GFCI/AFI circuit breaker and it wouldn't work. I suspected it was because the neutral and ground wires were attached to the same bar and that turned out to be the case.
The part itself is simple to install. Two screw holes match up with threaded holes on the subpanel. There are four places where you can install it. I chose the lower right position because it's easy to access and there's no chance the ground wires would come in contact with the load wire above.