A variation of this week's question was asked many years ago but study methods continue to evolve. IEEE 1584 - 2002 provides a table for suggested working distance to be used for the incident energy calculations. The distances are:

18 inches - Low Voltage MCCs and Panels
24 inches - Low Voltage Switchgear
36 inches - 5 kV and 15 kV Switchgear

Here is this week's question

Do you use the working distances from IEEE 1584:
Yes
No
Depends on the situation
Something else

Feel free to give us your thoughts about the working distance.