ARSD 20:44:22:24. Working space about electrical equipment operating at 600 volts, nominal, or less

In new structures, additional working spaces for switchboards, panelboards, and motor control centers operating at 600 volts, nominal, or less, to ground shall extend two feet from the front of the dedicated space and two feet from the top of the working spaces specified in the National Electrical Code. This applies only to items not a part of the electrical installation.