Square D 9421LR1 400A 600V Circuit Breaker, NEMA 3R, NEMA 1 | AmpState

Built for dependable panel protection, the Square D 9421LR1 is a genuine 400A, 600V circuit breaker designed to integrate seamlessly with panelboards, load centers, and electrical distribution systems. This part is ideal for replacement projects and stocking spares, ensuring your BOM stays aligned with the original installation and minimizing downtime.

• Exact BOM-aligned replacement — The 9421LR1 preserves original equipment specifications, helping you maintain consistency and reduce procurement guesswork when you’re repairing or upgrading a distribution system.
• Indoor and outdoor versatility — NEMA 3R rating for outdoor environments and NEMA 1 suitability for indoor panel applications provide flexible protection across different job sites.
• High-current, reliable protection — 400 A at up to 600 V gives robust protection for demanding electrical distribution scenarios without compromising performance or safety.
• Genuine Square D compatibility — A trusted part from the Square D family, designed to fit alongside existing Square D / Schneider Electric components and ecosystems.
• Supportive sourcing — Available from AmpState with expert guidance to verify fit and compatibility for your specific panel or distribution setup.

Ideal use cases include replacement installations in panelboards and load centers where the original part number matters, stocking spares to cut downtime during maintenance, and retrofitting systems that require a 400 A, 600 V protection device. By choosing the 9421LR1, you’re prioritizing reliable protection, streamlined maintenance, and a seamless fit with your existing electrical distribution network.

Need help confirming compatibility? Message AmpState with your panel model and labeling details, and we’ll help you verify that the 9421LR1 is the right fit for your system.