I recently learned about a new species of breaker panel known as the "plug-on-neutral" design. All the major load center manufacturers seem to be making these now. The idea is to provide a neutral bar at a fixed distance on each side of the bus bars, so specially-designed AFCI or GFCI breakers can plug directly onto the bus bar and the neutral bar without requiring a pigtail connection. Here's a picture from a catalog:
The extra-long breakers in the middle are the AFCI ones which snap directly onto the neutral bar. Very clever!
But I'm confused about how this panel could be configured as a subpanel. In the picture the two neutral bars are clearly connected (somehow, where is the bonding strap?) and they are connecting both neutrals and grounds to both. In a subpanel, the neutrals and grounds must be separated.
Does this mean one of those bars must be separated from the neutral somehow, in which case the fancy plug-on breakers would be limited to one side of the panel? Or can they both be isolated and a separate ground bar installed (how?)
It seems like it would be a waste if only one side could take advantage of the plug-on AFCI/GFCI, since almost every room requires one or the other now.