Meaning
Safety standards for industrial machinery provide the criteria for electrical components and wiring practices to prevent fire or shock hazards. The nfpa 79 safety listing indicates that a piece of equipment complies with the National Fire Protection Association electrical standard for industrial machinery. Manufacturers use this designation to satisfy local building codes and insurance requirements during factory commissioning.
Industrial Scope
Compliance covers all electrical and electronic elements of a machine operating from a point of connection to the supply. Hand tools or portable equipment do not fall under this standard. The nfpa 79 safety listing applies to machine tools and assembly robots.
Wiring Integrity
Conductors must be sized correctly for the load and protected by appropriate overcurrent devices. Color coding and labeling are required for all internal wires to facilitate safe maintenance. Enclosures must provide protection against dust and liquids common in factory environments.
Emergency stop circuits must meet specific redundancy and reliability levels.
Certification Path
Third party testing laboratories audit the design and construction of the machine to grant the listing. This process involves a line by line review of the schematics and physical testing of the insulation. Failing to secure the nfpa 79 safety listing before the machine arrives at the site can prevent the power from being turned on by local inspectors.
Retrofitting a non compliant machine in the field is significantly more expensive than building to the standard from the start.
