When cable trays pass through walls or floors, seal openings using fire-rated penetration sealing materials. Do not modify or damage the tray coating or structure during use. Route Planning and Layout Principles Coordinate with Building Structure: Cable tray routing should align with architectural design, avoiding unnecessary. Scope: Firestopping for busway, cable trays, cables, and trunking passing through walls in enclosed electrical installations. This practice is mandated by NEC 300. 21, which requires that electrical installations be made so that. When fire-rated cable tray requirements appear in a project specification, confusion usually comes from mixing together product standards, installation rules, and fire-test standards as if they were the same thing. The mostly combustible cable sheaths and.
