Siemens | JD3B300 | Circuit Breaker | 300A | 3-Pole | 240V | 65kA

Meet the Siemens JD3B300 circuit breaker—a robust, three-pole protection solution designed for demanding three-phase systems. With a 300 A rating, 240 V operation, and a 65 kA breaking capacity, it’s engineered to safeguard feeders, motors, and transformers in industrial and commercial panels. Perfect for maintenance, retrofit, or replacement projects where exact specifications matter, the JD3B300 ensures continuity and protection without guesswork.

Key specifications

• Amperage: 300 A
• Poles: 3-Pole
• Voltage: 240 V
• Short-Circuit Breaking Capacity: 65 kA
• Part Number: JD3B300
• Brand: Siemens

Why this breaker matters

In three-phase power systems, precise overcurrent protection is crucial. The JD3B300’s 65 kA breaking capacity supports higher fault currents common in industrial environments, reducing the risk of equipment damage and unexpected downtime. Its 240 V rating makes it compatible with standard commercial and light industrial distribution, delivering predictable, reliable trip behavior when faults occur.

Fit, compatibility, and installation tips

Always confirm fit and ratings before ordering. The part number JD3B300 is your most reliable reference for compatibility with Siemens panels and existing protection schemes. When replacing like-for-like, ensure the panel’s bus configuration and protective coordination align with a 3-pole, 300 A, 240 V device to maintain correct fault current paths and code-compliant protection.

Use cases and ideal environments

• Three-phase motor circuits driving conveyors, pumps, and compressors
• Power distribution panels in manufacturing facilities and warehouses
• UPS and critical load sections in data centers requiring dependable short-circuit protection

What sets it apart

Siemens JD3B300 is purpose-built to integrate seamlessly with Siemens panels and standard 3-phase distributions. Its 65 kA breaking capacity delivers strong fault resilience, while the 300 A, 3-pole, 240 V configuration provides a precise, matched protection profile for typical industrial and commercial installations. This isn’t a generic part—it’s a deliberate match for systems that demand reliable, predictable protection in everyday operation and during fault events.