Square D QOU3401021 40A 3P Circuit Breaker | AmpState

Meet a trusted workhorse for electrical protection—the Square D QOU3401021 40A 3P Circuit Breaker. Built for everyday electrical work, this unit provides reliable circuit protection in panelboards, load centers, and electrical distribution systems. With a 40-amp trip rating and three poles, it is tailored for 3-phase configurations where consistent protection matters.

Whether you're a maintenance technician, a panel builder, or maintaining spare inventory, this direct part-number match delivers peace of mind when time and accuracy matter. The QOU3401021 is specifically designed to slot into compatible Square D panels and distribution setups without guesswork.

Key features and benefits

• 40 A, 3-pole circuit breaker ideal for 3-phase circuits in commercial or industrial panelboards and load centers.
• Direct part-number match ensures compatibility with Square D systems, reducing selection errors on job sites.
• Reliable protection helps guard wiring and equipment from overloads and short circuits, supporting safer electrical distribution.
• Compact integration fits standard Square D enclosures, enabling clean, organized panel layouts.
• Availability from AmpState to support maintenance schedules, emergency stock, and project pipelines.

Who is this for

This breaker is a smart choice for service teams, panel builders, and anywhere you maintain stocked parts for Square D installations. If you’re assembling or upgrading 3-phase distributions, this 40A 3P unit keeps spare panels ready and reduces downtime on site.

Practical guidance

• Confirm compatibility with your panelboard or load center by referencing the part number QOU3401021 and Square D branding.
• Keep a few units in reserve for quick replacements during routine maintenance or fault isolation in 3-phase systems.
• When in doubt about fit, AmpState offers support to verify compatibility and fitment before purchase.

Ready to secure reliable protection with a direct part-number match? Add the Square D QOU3401021 40A 3P Circuit Breaker from AmpState to your toolbox, and keep your electrical distribution running smoothly.