Actually, you don’t have to meet raceway mechanical continuity requirements when using open-bottom equipment. This is because a new Exception added to Sec. 300.12 in the 2008 Code cycle provides this relief, as when raceways are stubbed into open bottom large equipment such as switchboards, motor control centers, and pad-mounted transformers. The 2005 NEC had no specific provision to permit this type of installation. Be careful here: the raceway, including the end fitting, cannot rise more than 3 in. above the bottom of the enclosure. Inspectors will ticket you if this maximum rise is exceeded.