240.22

That is the location of the overcurrent device. Grounded conductors are protected by the O/C device in the ungrounded conductors. (hence 250.122 and the grounding conductor) but that is still in conflict with 240.4

Never looked for this before because I always knew you didn't want to fuse a neutral because of the danger of single circuits not having a ground path but here are the code sections prohibiting overcurrrent protection of a grounded conductor:
230.90(B) and 240.22 and exceptions when the overcurrent device opens all the ungrounded conductors simultaneously with the grounded one and for certain motor overload protection installations.

Thanks for the info....