NEMA Releases Revision of Magnet Wire Standard

December 29, 2005

The National Electrical Manufacturers Association (NEMA) published MW 1000-2003, Revision 1, 2005 - Magnet Wire.

Significant changes in Revision 1 include:

1. The addition of bare wire dimensions, minimum insulation builds and performance requirements for half-wire sizes 4.5. - 29.5 AWG.
2. New MW 37-C and MW 38-C specifications for round and rectangular copper magnet wire, class 220 polyester (amide)(imide) overcoated with polyamideimide.
3. Expansion of specifications MW 15-C, MW 35-C and MW 73-C to include quad build dimensions and requirements.
4. The addition of MW 130-C and MW 131-C specifications for class 130 polyurethane and polyurethane/ polyamide overcoated self-bonding magnet wire, and MW 135-C and MW 136-C specifications for class 155 versions of these materials.

Divided into four major sections, the standard presents all NEMA standards for magnet wire in a single binder.

• Part 1 provides general requirements common to all types of magnet wire, including ordering information, general material requirements, general test conditions, definitions and manufacturing data in support of thermal rating, as well as dimensions with metric equivalents for all bare, minimum insulation increase and overall dimensions.
• Part 2 consists of product specification requirements (other than dimensions) for magnet wire with different types of coatings or coverings.
• Part 3 contains the test procedures to be followed and corresponding tables of specific test values to be attained in determining compliance with the requirements given in Part 2.
• Appendix B consists of definitions, requirements and recommended test procedures for reusable magnet wire packaging, standardized dimensions for spools and reels and formatting for the labeling of magnet wire products.

Source: National Electrical Manufacturers Association (NEMA).