This requirement covers a variety of industrial control panel applications. Basically, it covers control panels operating from a voltage of 600 volts or less. It also applies to industrial control panel enclosures and panels intended for flame safety supervision of combustible fuel type equipment, elevator control, crane or hoist control, service equipment use, marine use, air conditioning and refrigeration equipment, and for control of industrial machinery including metalworking machine tools, power press controls and plastic injection molding machinery.