Square D QO Main Breaker, Bolt-On, 120/240VAC

Square D QO Main Breaker, Bolt-On, 120/240VAC

The Square D QO Main Breaker is a thermal magnetic circuit breaker engineered to provide overcurrent protection and switching for QO and Homeline load centers. Rated for 120/240 V AC operation and designed for bolt-on mounting, this breaker features an over-center, trip-free toggle mechanism with quick-make, quick-break action for dependable performance on ac and dc systems. It is UL Listed and CSA certified, making it a trusted choice as a main breaker for residential and light commercial electrical panels where consistent, code-compliant circuit protection is required.

Key Features

• Trip-Free Toggle Mechanism: Over-center, quick-make, quick-break toggle design delivers positive, reliable switching action independent of handle position, helping prevent nuisance operation.
• Bolt-On Mounting: Secure bolt-on connection for firm, vibration-resistant attachment to compatible QO and Homeline load centers.
• Rated Operational Voltage: 120/240 V AC rating supports standard residential and light commercial branch circuit and main service configurations.
• Wire Range Compatibility: Accepts AWG 4...AWG 2/0 aluminum/copper conductors with a tightening torque of 6-6 N.m, 4-65 mm² (AWG 12...AWG 2/0), simplifying field termination.
• Overcurrent Protection: Thermal magnetic trip elements protect ac and dc systems from overload and short-circuit conditions, functioning as the main breaker for the load center.
• Mercury-Free Construction: Manufactured without mercury for safer handling, installation, and disposal.
• Accessory Compatible: Designed to work with a range of Square D QO accessories, including handle locks, alarm switches, and auxiliary trip devices, for expanded panel functionality.

Certifications & Compliance

• UL Listed
• CSA Certified
• RoHS EU Compliant with Exemptions

Technical Specifications

• Warranty: 18 months
• Poles Description: 2P
• Range Of Product: QO
• Mercury Free: Yes
• Packaging: 1 ea

Typical Applications

• Residential and Light Commercial Load Centers
• QO and Homeline Load Center Systems
• Main Service Disconnect Applications
• Overcurrent Protection for AC and DC Systems
• Panelboard and Load Center Renovation or New Construction
• Electrical Service Upgrades and Panel Replacements

Why Square D?

Square D engineers the QO Main Breaker with a proven trip-free toggle mechanism and secure bolt-on mounting for dependable, code-compliant overcurrent protection. Backed by an 18-month warranty and certified UL Listed and CSA, this breaker is built for electricians and contractors who need reliable, consistent performance from the main breaker in QO and Homeline load centers, whether for new construction or panel upgrades.