Square D QOB145 - 45 A, 120 V, 1-Pole Bolt-On Circuit Breaker | AmpState

Introducing the Square D QOB145, a rugged 45A, 120V, 1-pole bolt-on molded case circuit breaker designed to defend your panelboards and load centers from overcurrent and short-circuit events. Built for dependable, long-term service in residential, commercial, and light industrial environments, this breaker delivers a secure, solid connection right at the source of power.

Key advantages that matter in real-world installations

• Secure bolt-on mounting provides a rigid, vibration-resistant bus connection, minimizing the risk of loose terminations in demanding electrical panels.
• Thermal-magnetic trip unit offers stable, repeatable protection: the thermal element responds to sustained overloads, while the magnetic element reacts instantly to short circuits for fast isolation.
• 1-pole, 45A, 120V configuration is tailored for single‑phase branch circuits needing robust protection against overcurrent in a compact form factor.
• Molded case construction delivers durability and reliable performance in panelboards and load centers subjected to vibration or busy service environments.
• OEM-compatible design is engineered to work with matching Square D OEM load centers and panelboards, ensuring a proper fit and dependable electrical performance.

Where and how you’ll use the QOB145

This breaker is ideal for protecting a dedicated 120V branch circuit in residential panels as well as light commercial or light industrial setups. Use it to guard circuits feeding high-demand outlets, lighting runs, or small equipment that requires solid protection against both overloads and short circuits. Its bolt-on style makes it a preferred choice in panels where a robust, vibration-resistant connection is critical for ongoing reliability.

Why choose the Square D QOB145 over generic alternatives

• The combination of bolt-on mounting and a thermal-magnetic trip unit delivers a dependable, repeatable protection scheme that’s consistent with standard electrical infrastructure.
• Compatibility with OEM load centers and panelboards helps you avoid awkward adapters or mismatched components, reducing installation challenges and future maintenance risk.

Practical notes for installation and care

• Ensure power is fully controlled and panel access follows your site’s safety procedures before mounting.
• Mount the breaker using the designated bolt-on fasteners, then secure connections to the bus to maintain a solid electrical path.
• Periodically inspect the terminations and surrounding wiring for signs of wear, discoloration, or loosening, and replace if any concerns arise.

Technical snapshot

• Manufacturer: Square D
• Part Number: QOB145
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 45A
• Voltage Rating: 120V
• Number of Poles: 1
• Mounting Style: Bolt-on
• Applications: Branch circuit overcurrent and short-circuit protection