This standard describes the installation and maintenance procedures for low-voltage motor control centers (MCCs) rated 600 VAC or less with a horizontal bus rating of 2,500 amperes or less. MCCs may be assembled with factory-installed dry-type transformers and panelboards. The testing and maintenance of such dry-type transformers is addressed in NEC 409, Standard for Installing and Maintaining Dry-Type Transformers (ANSI). The testing and maintenance of such panelboards is addressed in NECA 407, Standard for Installing and Maintaining Panelboards (ANSI).