Square D QHB330 - 300 A, 3-Pole Bolt-On Circuit Breaker | AmpState

Square D QHB330 is a rugged 300A, 3-pole bolt-on molded case circuit breaker designed to deliver dependable branch circuit overcurrent and short-circuit protection for panelboards and load centers. Built to endure demanding environments, this unit pairs Square D’s proven reliability with a straightforward bolt-on installation that promotes a rigid, vibration-resistant bus connection.

• Secure bolt-on mounting provides a rigid, vibration-resistant bus connection, helping maintain consistent protection even in environments with equipment or mechanical vibration.
• Thermal-magnetic trip unit delivers stable, repeatable protection by combining thermal overload sensing with magnetic instantaneous trip for fast response to short circuits.
• Three-pole, 300A protection ideal for three-phase feeders and large branch circuits, enabling reliable power distribution in commercial and light industrial panels.
• OEM compatibility designed to be used with matching Square D OEM loadcenters and panelboards, ensuring proper fit, coordination, and electrical performance.
• Versatile applications suitable for residential, commercial, and light industrial installations requiring robust protection and straightforward maintenance.

Use this circuit breaker to safeguard feeders and critical equipment from overloads and short circuits, reducing the risk of costly downtime and equipment damage. Its bolt-on design simplifies retrofits and upgrades within existing Square D panels, making it a practical choice for service upgrades, panel refurbishments, or new installations that demand reliable protection with minimal complexity.

Key specifications

• Manufacturer: Square D
• Part Number: QHB330
• Type: Thermal-magnetic molded case circuit breaker
• Amperage Rating: 300A
• Number of Poles: 3
• Mounting Style: Bolt-on
• Application: Branch circuit overcurrent and short-circuit protection

Practical installation and use tips

• Pair this QHB330 with compatible Square D panelboards to ensure optimal alignment and protection coordination across your electrical distribution system.
• Before installation, verify panelamp compatibility and confirm that the service environment matches the device’s ratings for continuous operation.
• For long-term reliability, inspect mounting hardware and bus connections during routine maintenance and replace the unit if wear or arcing signs appear.

In summary, the Square D QHB330 offers a high-capacity, three-pole bolt-on solution that combines secure mounting, precise thermal-magnetic protection, and OEM-aligned compatibility. It’s a purpose-built choice for professionals who demand durable, field-ready protection for both new builds and panel upgrades.