The XT5HU330AMFF0C0XXX: The description field reads XT5H 400 MCP 300 3P UL. Breaking that down: XT5H is the series (high-performance molded case protector), 400 is the frame size in amperes, MCP stands for motor circuit protector (meaning it has adjustable magnetic trip settings for motor starting inrush), 300 is the continuous current rating in amperes, 3P is three-pole, and UL confirms the listing to UL 489 or UL 1066. This is not a standard molded case circuit breaker for general distribution — it is a motor circuit protector designed for coordinated motor branch circuit protection per NEC Article 430.
Deployment context
This protector mounts in a panel or switchboard via the XT5H fixed or plug-in base. The 400 A frame size means it occupies the full-width mounting footprint of the XT5 family — plan for busbar or cable connections rated for the 300 A continuous load. In a motor control center, it typically feeds a contactor and overload relay downstream, providing short-circuit protection while the overload handles running overcurrent.