Ken,
There is a ton of work @ <240 that requires PPE greater than 2. Some people use Table 130.7(C)(9)(a) Hazard/Risk Category Classifications for their PPE selection in lieu of performing a detailed calculation. The two portions of the table that related to panelboards at 240 and below, require you to refer to Notes 1 and 3.
There are lots of 240V installations that have short circuit currents in excess of 25kA and fault clearing time greater than 2 cycles.
If the short circuit currents is in excess of 25kA or the fault clearing time is greater than 2 cycles or you don't check either of those two items, then you cannot use that table and must perform the detailed calculation.
Notes:
1. Maximum of 25 kA short circuit current available, 0.03 second (2 cycle) fault clearing time.
3. For < 10 kA short circuit current available, the hazard/risk category required may be reduced by one number.
