Sorry about not giving more info. This is a Square D service entrance box (meter on left half) with 2 - 200 amp main circuit breakers in the right half. This is how it came from Square D. That's why I question why Square D can do this with a listed item. The insulation isn't broken on any of the 90 degree bends, I looked very carefully.
It's not just Square D... I've seen the same in Cutler Hammer, Siemens, Allen Bradley, Furnas panels and MCC's out where I work..... UL governs safety of equipment, NEC governs safety of it's installation
They can do this because they test it like that, and it passes. They can do a lot of other things that are illegal per NEC, too, for the same reason- smaller conductors, for instance. NEC is rather conservative, as we all know.
So, don't look at it as exceeding the bend radius for cable, look at it as insulated cylindrical busbar!
Well put, Steve. Remember the NEC has to be a very conservative catch all for many unseen installation parameters, that may or may not happen. The manufactures of these panels can test these units under controlled conditions. Then they specify the conditions, that these panels are used under, by listing them that way.