Square D QOU345 - 45 A, 240 V, 3-Pole Bolt-On Circuit Breaker | AmpState

Square D QOU345 is a 45A, 240V, 3-pole bolt-on molded case circuit breaker engineered for dependable branch circuit protection in panelboards and load centers. With a rugged bolt-on mounting, a precise thermal-magnetic trip unit, and seamless OEM compatibility, this breaker is built to perform in demanding residential, commercial, and light industrial environments.

Why this breaker stands out

• Secure bolt-on mounting delivers a rigid, vibration-resistant bus connection that stays tight in active electrical spaces, reducing the risk of loose contacts over time.
• Thermal-magnetic trip unit provides stable, repeatable protection across a range of fault conditions, combining precise overload sensing with rapid short-circuit interruption.
• 3-pole design for 3-phase systems ensures reliable protection for multi-wire circuits common in commercial and light industrial panels.
• OEM-compatible design means straightforward replacement or upgrades within matching Square D panelboards and load centers, preserving factory-listed safety and performance.
• Versatile application suited for residential service subpanels, commercial distribution boards, and light industrial equipment enclosures—where dependable overcurrent and short-circuit protection matters most.

What problems it solves

When a circuit experiences overloads or short circuits, the QOU345 quickly interrupts power to prevent damage to wiring, equipment, and occupants. The thermal-magnetic mechanism minimizes nuisance trips from minor surges or temporary faults, while the robust bolt-on mount reduces vibration-induced connection wear—extending panel reliability in busy installations.

Specifications at a glance

• Manufacturer: Square D
• Part Number: QOU345
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 45A
• Voltage Rating: 240V
• Number of Poles: 3
• Mounting Style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Ideal use scenarios

Consider the Square D QOU345 for:

• Upgrading or replacing breakers in OEM panelboards and load centers that require a 3-pole, 45A, 240V bolt-on solution
• Protection of multi-phase feeders in light commercial electrical rooms
• Dedicated circuit protection for mid-size equipment or motor loads within residential-adjacent commercial spaces

Installation and compatibility tips

Pair this breaker with matching OEM Square D panelboards and load centers to maintain listed safety performance. When installing, ensure the bus connection pattern and panel ratings align with a 3-pole, 45A, 240V configuration. Follow standard electrical practices for bolt-on devices, including proper torque and secure mounting, to maximize reliability and safety.

Available from AmpState, this QOU345 adds a dependable, code-compliant solution for protecting distribution circuits where fast fault interruption and durable mounting matter most.