Punching 2" hole into breaker panel

[don_resqcapt19]

One falls under "wire bending space at terminals" the other does not.

Under the NEC, yes, but I believe UL 67 use the same wire bending space table for all conductor bends in the panel.

 

[kwired]

Expansion fittings are the most common method used to comply with 300.5(J).

Earth settlement or frost - expansion fitting protects the raceway and whatever it connects to, conductors still need room to move - large conductors like 4/0 and larger just don't cooperate, especially in cold conditions and they put strain on terminations regardless - that has been my observation.

The best thing I have seen to protect from frost heave or settling is to either place conduit all the way to bottom of trench if in undisturbed soil, fill with something that naturally will compact easily like sand or gravel, find a way to compact what it below your raceway so it can't settle, and to make sure the burial depth is below the typical maximum frost depth for the area.