Use of AWM type cables and conductors
Regarding the permission of AWM type cables and conductors the new NFPA 79 - 2012 edition provides both machine builders and engineers a list of new opportunities. According to the old 2007 edition the use of AWM type single conductor or multi-conductor was not permitted (Exception: When part of a “Listed Assembly“).
Under the terms of NFPA 79 - 2012 edition (chapter 12.9), AWM type cables and conductors shall be permitted as follows:
- Where part of a “Listed Assembly“
- AWM identified for use with approved equipment and used in accordance to the manufacturer‘s instructions
- Construction meets all requirements of section 12.2-12.6 incl. modifications with regards to stranding, flame-resistance, insulation thickness and markings
Caution regarding exceptions
Realized revisions are not a general approval for appliance wiring material (AWM). The use is still based on exceptions. The obligation to produce proof has to be written down in the machine‘s technical documentation by the responsible machine builder.
UL listed products
With regards to the use of listed cable and conductors there have been no changes within NFPA 79 - 2012 edition. Listed products can still be used for exports.
Some US-states still refer to elderly versions of NFPA 79 as the legal basis. To set an example: NEC 2011 refers to NFPA 79 - 2007 edition. To handle that problem efficiently, the best way is to learn what edition is valid for the machine‘s target destination in advance.
US Department of Labor (OHSA.)
OSHA: Occupational Saferty and Health Administration
OSHA: Overview of all NRTLs accredited by OSHA
Some accredited third-party certification bodies able to approve machines for usage in the USA (testing centers, National Recognized Testing Laboratories)
Intertek ETL SEMKO
UL Underwriters Laboratories
US standards and their publishers (supply source) :
NEC National Electrical Code
NFPA 79 Electrical Standard of Industrial Machinery