ACW400PFMU4003 400A 3P 480V Circuit Breaker | AmpState

ACW400PFMU4003 is a 400 A, 3-pole, 480 V circuit breaker built for everyday electrical protection in panelboards, load centers, and distribution systems. In field service, its robust design and direct part-number compatibility make it a reliable choice for maintenance teams, panel builders, and spare inventories where fast, correct part replacement matters.

Why it matters to your operation: fewer downtime moments caused by incorrect replacements, streamlined stocking, and predictable performance when you need to interrupt fault currents and protect wiring and devices downstream.

Key specifications

• Amperage: 400 A
• Poles: 3
• Voltage: 480 V
• Part Number: ACW400PFMU4003
• Manufacturer: Brand Not Specified
• Applications: Circuit protection in panelboards, load centers, and electrical distribution

Designed for professionals who count on reliability

This breaker is a smart pick for teams that maintain or assemble electrical panels where a direct part-number match matters. Keep a ready-to-install component in your service kit or spare stock and accelerate maintenance or retrofit projects without guesswork.

Usage scenarios

• New panel installations where the catalog lists ACW400PFMU4003 as the matching device
• Retrofitting or upgrading existing distribution boards that require a 400 A, 3‑pole, 480 V breaker
• Routine maintenance replacements in industrial or commercial facilities with standard 480 V distribution systems

Need help matching a part number or confirming compatibility? Message us and we’ll help you confirm the fit.

Available now from AmpState — ensure your panel protects critical loads with a precise, dependable circuit-breaker solution.