Westinghouse | NB2900S | Circuit Breaker | 900A | 2-Pole | 600V | Bolt-On

Meet the Westinghouse NB2900S Circuit Breaker—a rugged, high-current protective device designed for demanding electrical environments. This 2-pole unit handles up to 900A at 600V and features a bolt-on mounting for a secure, durable connection in retrofit, maintenance, and replacement projects where exact specifications matter. Built to endure vibration and demanding service conditions, the NB2900S helps keep critical power distribution protected and operating smoothly.

Key specifications

• Amperage: 900A
• Poles: 2-Pole
• Voltage: 600V
• Mounting: Bolt-On
• Compatibility reference: Part number NB2900S is the best reference for compatibility

Why this NB2900S stands out

The NB2900S combines a robust bolt-on design with high-current capability, making it a reliable choice for service entrances, industrial panels, and heavy-duty distribution networks. The bolt-on mounting provides a solid mechanical connection that resists loosening from vibration or thermal cycling, reducing the risk of intermittent outages. With a 600V rating and 900A capacity, this breaker is suited to protect large feeders and main circuits where dependable, fast interruption is critical during fault conditions or overloads.

Ideal use cases

• Retrofit projects in industrial facilities upgrading to higher-current protection while maintaining panel compatibility
• Replacement installations where exact NB2900S specifications are required
• Primary or main-disconnect applications in large electrical panels and service enclosures
• Maintenance outages that call for a like-for-like, secure, bolt-on protective device

Installation, compatibility, and care

To ensure a correct fit, always align the unit with the panel’s mounting pattern and confirm the ratings match your system’s requirements. Confirm fit and ratings before ordering. The part number NB2900S is the best reference for compatibility, helping you avoid mismatches in mounting, electrical characteristics, and enclosure fit. When installing, ensure proper torque on mounting hardware and verify conductor sizing and terminations meet your system’s 900A protection needs. This approach minimizes downtime and maximizes protection reliability.

Practical insights and tips

• Document the exact panel model and existing protection settings before replacing any breaker to streamline compatibility checks.
• Use the bolt-on design in panels that require a rigid, vibration-resistant connection to withstand industrial operating conditions.
• Plan for a maintenance window that allows verification of electrical integrity after installation, including insulation resistance and contact cleanliness.
• Consider pairing with appropriate overcurrent protection coordination to ensure selective tripping and minimized disruption during faults.