Square D QO350 - 50A, 3-Pole, Miniature Circuit Breaker (MCB)

Engineered for dependable overcurrent protection in demanding electrical environments, the Square D QO350 50A 3-Pole Miniature Circuit Breaker (MCB) delivers reliable tri-phase protection in a compact, easy-to-install package. Designed for panelboards, switchboards, and control panels, this MCB provides safe, consistent interruption when faults arise, helping keep critical systems up and running.

• Current rating: 50A
• Poles: 3-Pole
• Breaker type: Miniature Circuit Breaker (MCB)
• Family: Square D QO series

Why the 3-Pole design matters

For three-phase systems, a 3-Pole MCB like the QO350 provides synchronized protection across all phases. That means when an overload or short circuit occurs, all affected lines can be interrupted together, reducing the risk of unbalanced loads and equipment damage. This makes it especially suitable for motor control centers (MCCs), three-phase panelboards, and industrial or commercial distribution networks where reliable, coordinated protection is non-negotiable.

Ideal applications and scenarios

• Industrial panelboards that feed motors and conveyors where three-phase protection is essential
• Commercial switchboards requiring robust overcurrent protection in a compact form factor
• OEM equipment enclosures and control panels needing a dependable 50A, 3-pole protection solution

What sets this MCB apart from generic breakers

• Trusted reliability from the Square D QO line, known for consistent performance in distribution panels
• Compact, versatile configuration that fits a wide range of enclosures and simplifies panel design
• Clear compatibility with three-phase systems to ensure proper protection coordination and system uptime

Practical tips for installation and use

• Confirm your enclosure is compatible with the QO family to ensure a seamless fit and secure mounting
• Verify wiring terminals and torque specifications recommended for QO MCBs to maintain reliable connections
• Pair the QO350 with appropriate protective coordination to balance protection needs across feeders and branch circuits

For engineers and technicians designing or upgrading electrical distribution, the Square D QO350 delivers precise, dependable 50A three-pole protection, helping you safeguard equipment, minimize downtime, and maintain safe, compliant operation in panelboards, switchboards, and motor control centers.