In Episode 24 of “EC&M Tech Talk,” Randy Barnett, a journeyman electrician, inspector, author, trainer, and electrical safety expert, reviews many of the requirements in the National Electrical Code, the NFPA 79, Standard for Industrial Machinery, and NFPA 70B, Standard for Electrical Equipment Maintenance.
Beginning with an example of common terminology used in the field, Randy explains the importance of using the correct terminology found in the NEC. For example, disconnect switch is not defined in the NEC. The disconnect switch often referred to mounted on the wall is a safety switch. A safety switch is just one example of a device that provides a disconnecting means for specific equipment and circuits. In the Index of the NEC, seventy different applications of disconnecting means can be found.
Among the important requirements discussed are for durable and legible markings on the disconnecting means, both open and closed lockable positions, and the general requirement for disconnecting means to be within sight from the equipment it disconnects from its source of power. Specified application examples include air conditioning/refrigerating equipment, room air conditioners, and motors.