Re: NEC 110.34B - Definition of "effectively separated&
This is a ?context? Section. Read it along with 110.31(B)(1), 110.31 (C)(1) and 110.31(D). Read its exception along with 110.31(B)(2) and 110.31(C)(2).
Remember, the NEC always assumes (correctly or not) that application of a Section is consistent with the rest of the Code.
In this case, the main rule of 110.34(B) assumes the installation ?over 600 Volt space? is consistent with 110.31(B)(1), (C)(1) or (D), so the combined ?mixed-space? is potentially accessible to unqualified persons. The Exception emphasizes that the main rule only applies to unqualified persons.
If this were the case, unqualified persons must be ?separated? from access to the ?over 600 Volt? space by ??by a suitable partition, fence, or screen;? or, if necessary, they may enter under appropriate administrative rules. (The NEC doesn?t say that last part but NFPA 70E does.) With the ??suitable partition, fence, or screen? in place, ?workspace? required by 110.34(A) must also be maintained.