Square D | QOB3151021 | Circuit Breaker | 3-Pole | 240V | Bolt-On

Engineered for reliability in commercial and industrial electrical panels, the QOB3151021 is a three-pole, 240-volt bolt-on circuit breaker designed for maintenance, retrofit, and replacement scenarios where exact specifications matter. This Square D component keeps your electrical protection consistent with the rest of the system, helping you maintain safe, uninterrupted power delivery.

What makes this breaker stand out

• Three-Pole, 240V Configuration: Suitable for three-phase circuits, delivering balanced protection across all phases in a single, integrated unit.
• Bolt-On Mounting: Secure, robust installation that stays firmly seated even in vibration-prone environments, reducing the risk of loose connections over time.
• Part Number Precision (QOB3151021): The exact reference you need for compatibility and seamless replacement within compatible Square D panels.
• Maintenance, Retrofit, and Replacement Ready: Ideal whenever you’re upgrading, repairing, or standardizing protection in existing electrical infrastructure.
• Voltage Rating: 240V, matching standard three-phase service expectations in many commercial and industrial applications.

Ideal use cases

• Retrofits in three-phase panel boards where a bolt-on 3-pole 240V breaker is required.
• Maintenance upgrades to restore or improve protective coordination in aging electrical systems.
• Replacement of failed or out-of-spec breakers with a genuine Square D part that aligns with your panel’s ratings.
• New installations in systems designed around the QOB bolt-on format for durable, serviceable protection.

How it benefits your project

Choosing the QOB3151021 means you’re aligning with a trusted, OEM-rated solution that emphasizes secure mounting, clear fitment, and predictable performance. The bolt-on design minimizes the risk of arcing or loosening under load, while the three-pole layout ensures synchronized tripping across all three phases. When you’re updating a panel, this breaker helps you preserve protection coordination and simplifies future servicing thanks to its clear part-number identity and compatible bolt-on footprint.

Compatibility and practical notes

Before ordering, confirm that your panel accepts a 3-pole, 240V bolt-on breaker with the same form factor. The part number QOB3151021 is the most reliable reference for compatibility, ensuring you don’t mismatch with non-bolt-on or different-pole configurations. If you’re planning a retrofit or replacement, review your existing panel’s specifications and ensure the trip characteristics and ratings match your system requirements.

Installation and safety considerations

Install with the power fully de-energized and follow your panel manufacturer’s installation instructions. Bolt-on breakers require proper alignment with the bus and mounting point to maintain a solid electrical connection. If you’re unsure about the fitment or the panel’s ratings, consult documentation for your specific Square D enclosure or reach out to a qualified electrician to verify compatibility.

When you need a dependable, OEM-grade solution for three-phase protection at 240V, the Square D QOB3151021 delivers a concrete, serviceable choice for retrofit, maintenance, or replacement projects.