A. The switchgear lineup shall be free-standing, dead-front type, metal-clad mediumvoltage distribution switchgear. The switchgear shall be Arc-Resistant Type 2B per ANSI/IEEE C37.20.7. The lineup shall contain the necessary number of monitoring, control modules and distribution modules (sections), including optional accessories. The switchgear shall be a NEMA rated cabinet construction, for indoor applications. B. Arc Resistant Type 2B definition: Arc-resistant accessibility is designated for equipment where isolation is required for the instrument compartment and arcing does not cause holes in the freely accessible front, sides, and rear of the enclosure or in the walls isolating the low-voltage control or instrument compartment(s). Smoke ingress in the compartment under evaluation is acceptable. Partial or total distortion of internal compartment walls, without signs of burning from a direct arc strike (i.e., a hole) or openings in the walls (i.e., torn seams) are acceptable. The application of suffix “B” to accessibility type 2 requirements additionally qualifies the equipment for installation of instrument and control devices on the door or cover of the compartment tested without retesting the switchgear for the condition where the door or cover is present with devices mounted on it...
