Circular Mil is a system for specifying wire size by conductor area. The number is obtained by multiplying the individual average wire diameter (in inches) by 1,000, squaring the result and multiplying it by the number of wires. MCM is an older industry term denoting 1,000 circular mils ("M" = 1000 in Roman numerals, "CM" = circular mils). However, Underwriters' Laboratories (UL) and the National Electrical Code (NEC) changed their codes to the metric prefix KCMIL ("K" = metric equivalent of 1,000, "CM" = circular mils). In response to UL and the NEC, American Insulated Wire Corp. (AIW), Pawtucket, R.I., is incorporating the change of MCM to KCMIL on its products.

The first product family to be converted by American is building wire, which is used in power distribution applications. According to Marty Cooper, AIW's marketing director, although UL and NEC reference KCMIL, end-users and distributors alike still request products by the old MCM designation. To assist in the transition, American's new building wire labels will include both markings. In addition to KCMIL/MCM, the company's building wire label will include a UPA bar code for building wire products that are packaged in reels so the distributor can use the bar code for identification when drop shipped or for when the entire reel is bought as a single unit. The new labeling also will include two bar codes to meet the NAED and NEMA guidelines. One of the codes, used for inventory purposes, will include a vendor identification bar code and the other will provide a general description.

Want to use this article? Click here for options!
© 2007 Penton Media, Inc.