Square D QOB350 - 50 A, 240 V, 3-Pole Bolt-On Circuit Breaker | AmpState

The Square D QOB350 is a 50A, 240V, 3-pole bolt-on molded case circuit breaker designed to shield your electrical system from overcurrent and short-circuit events. Built for dependable branch circuit protection in panelboards and load centers, it delivers a secure, vibration-resistant connection and consistent protection performance in demanding environments.

• Secure bolt-on mounting ensures a rigid, vibration-resistant bus connection that stays put in busy electrical rooms or equipment cabinets.
• Thermal-magnetic trip unit provides stable, repeatable protection across varying temperatures and load conditions, reducing nuisance trips while still guarding against overloads and short circuits.
• 3-pole design for three-phase systems ideal for commercial and light industrial panels, supporting balanced protection for multi-wire circuits.
• Molded case, bolt-on style engineered for reliability in panelboards and load centers that require a secure, field-serviceable protection device.
• OEM-compatible specifically designed to work with matching Square D panelboards and load centers, ensuring clean wiring integration and dependable operation.
• Versatile application suitable for residential, commercial, and light industrial environments where steady, predictable overcurrent protection is essential.

Technical snapshot

• Manufacturer: Square D
• Part number: QOB350
• Type: Thermal-magnetic molded case circuit breaker
• Amperage rating: 50A
• Voltage rating: 240V
• Poles: 3
• Mounting style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Who should consider the Square D QOB350? This breaker is ideal for installers upgrading or fabricating panelboards and load centers that serve three-phase equipment, such as HVAC drives, pumps, commercial lighting systems, and other motor loads commonly found in small to mid-size facilities. If you’re outfitting a panel that demands a rugged, vibration-resistant connection and precise trip behavior, the QOB350 provides a dependable solution.

Practical tips for best results

• Pair with compatible OEM panels to ensure seamless mounting and electrical continuity.
• Use in environments where panelboard vibration or equipment movement is a factor to maximize long-term connection reliability.
• Plan for straightforward field replacement by selecting a bolt-on unit with a compatible trip curve for stable protection across temperature variations.