Cabling caution: Are you following the rules in and around machinery?
Rosemont, IL —Because of safety and liability issues, more time is being devoted to selecting and installing wire and cable used in and around industrial machinery to ensure performance reliability, noted
National Manufacturing Week
in late September.
National Fire Protection Association
79 (NFPA 79) Electrical Standard for Industrial Machinery was revised in 2007. Are you aware of the new requirements? Key points about this and other applicable standards follow.
NFPA 79 2007 Edition
says a single conductor or multi-conductor appliance wiring material (AWM) shall not be permitted, unless the completed assembly has been listed prior for such use.
|Maureen Broe, senior marketing communications, Lapp USA, used a piece of Lapp UL listed cable at National Manufacturing Week 2007 to point out some of what is and isn’t permissible for wiring in and around industrial machinery. Image by Mark T. Hoske, Control Engineering .|
According to NFPA, that standard “shall apply to the electrical/electronic equipment, apparatus, or systems of industrial machines operating from a nominal voltage of 600 volts or less, and commencing at the point of connection of the supply to the electrical equipment of the machine.” It doesn’t include “additional requirements for machines intended for use in hazardous (classified) locations,” NFPA adds.
Machine Tool Wire (MTW) is among permissible options for wire and cable, according to Lapp; communication cables, tray cables, and exposed runs are among areas covered in U.S. National Electric Code (NEC) 336, 392, 501, and 800. Cordage for machinery, for instance, falls under NEC 400. NFPA 79 machinery area is covered by
Underwriters Laboratories (UL) MTW / AWM
, according to Lapp information (which includes a list of conformant Lapp cables). Specific application areas include stationary control cables, continuous flex areas, such as robotics, stationary variable frequency drive cables, and motor supply power and bus cable.
Lapp’s Industry Machinery White Paper provides a detailed technical explanation of cabling requirements
Lapp Group cable and connector products include Lapp Olflex, Unitronic, and Etherline bus and Ethernet cables, Silvyn cable track and accessories, Epic Rectangular, Circular, and Pin & Sleeve Connectors, Skintop strain relief cable glands, Fleximark Cable Marking Systems, remote access ports, and custom harness assemblies.
Also read from Control Engineering :
Crush-resistant flexible cable
— Mark T. Hoske , editor in chief
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