Explosionproof-motor designs face compliance deadline

摘要

Electric-motor manufacturers seeking Underwriters Laboratories' (UL) "explosionproof" certification face a Dec 11, 2010 deadline that could change the way they design and build their products. On that date, UL will require that motors fully comply with the UL 674 standard before being labeled explosionproof. The UL standard breaks explosion proof motors (EPM) into classes, divisions, and groups defined by the environments and locations in which they can be used. EPM designers must look for leak paths where vapors could enter or leave the motor and initiate an explosion. EPM manufacturers generally use materials that pass UL's testing on a stand-alone basis because it speeds the UL-approval process for the overall EPM assembly.