Square D QOB330 - 30 A, 240 V, 3-Pole Bolt-On Circuit Breaker | AmpState

Meet the Square D QOB330—a 30 A, 240 V, 3-pole bolt-on molded case circuit breaker engineered for dependable branch circuit protection in panelboards and load centers. Its secure bolt-on mounting creates a rigid, vibration-resistant bus connection that stays tight under demanding conditions, helping you avoid nuisance trips and intermittent fault signals.

Key features that matter in the real world

• Bolt-on mounting provides a solid, vibration-resistant bus connection for long-term reliability in both residential-adjacent and commercial installations.
• Thermal-magnetic trip unit delivers stable, repeatable protection: fast magnetic response to short circuits and a responsive thermal element for overloads, reducing equipment damage and downtime.
• 3-pole design supports 3-phase systems, enabling balanced protection across all conductors in 240 V circuits.
• OEM compatibility with matching Square D load centers and panelboards ensures straightforward installation and dependable performance with your existing infrastructure.
• 30 A rating makes it ideal for protecting branch circuits feeding motors, lighting, and other essential loads in light-commercial and residential settings.

Why this breaker fits your panel and your schedule

The QOB330 is purpose-built for panelboard and loadcenter environments where a secure, bolt-on solution is required. If your installation demands a breaker that stays put through vibration, temperature swings, and regular maintenance cycles, this Square D unit delivers. Its thermal-magnetic protection minimizes arc faults and short-circuit damage, helping you keep critical systems—like lighting, HVAC, and small motors—safer and more dependable.

Technical specifications at a glance

• Manufacturer: Square D
• Part Number: QOB330
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 30 A
• Voltage Rating: 240 V
• Number of Poles: 3
• Mounting Style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Ideal applications and practical use cases

• New installations or replacements in panelboards/load centers that require a secure bolt-on breaker.
• Residential-friendly commercial spaces with 3-phase service or mixed-load panels.
• Light industrial environments where vibration resistance and robust connections matter for reliability.
• Motor loads, lighting circuits, and other branch circuits that demand consistent protection against overcurrent and short circuits.
• Upgrades or retrofits in OEM Square D environments to maintain compatibility and performance parity with existing gear.

How it compares in practical terms

Compared with plug-in alternatives, the Square D QOB330’s bolt-on design emphasizes stability and bus integrity in installations subject to vibration, equipment movement, or long-term wear. Its thermal-magnetic trip mechanism provides dual protection—fast magnetic trips for sudden faults and adaptive thermal trips for sustained overloads— helping prevent damage before it cascades into costly downtime.

In short, the QOB330 is a purpose-built solution for reliable, code-compliant protection in panelboards and load centers where secure mounting, precise protection, and OEM compatibility matter most. If you’re equipping 240 V, 3-pole circuits in residential, commercial, or light industrial settings, this breaker from Square D offers a dependable, straightforward path to safer, more resilient electrical systems.