These requirements cover metal-sheathed heating elements intended for use in appliances and equipment that comply with the requirements for such appliances and equipment. These requirements cover sheathed heating elements rated 600 volts or less. These requirements do not cover heating elements for use in equipment for use in hazardous locations as defined in the National Electrical Code, NFPA 70. Wherever the terms heating element and element are used in these requirements, they are intended to mean a sheathed heating element as defined in 2.4.