Siemens FXD63B250 Molded Case Circuit Breaker

Description

Siemens FXD63B250 Molded Case Circuit Breaker

Product Dimensions：

The Siemens FXD63B250 is a heavy-duty, Sentron series Molded Case Circuit Breaker (MCCB). It is engineered to provide reliable overcurrent, short-circuit, and thermal protection for industrial and commercial electrical distribution systems.

Product Detailed Description

The FXD63B250 belongs to the Siemens FD Frame family of circuit breakers. It features a non-interchangeable thermal-magnetic trip unit, providing both long-time (thermal) delay protection for overloads and instantaneous (magnetic) protection for high-fault short circuits.

As an “FXD” type breaker, it offers a higher interrupting rating compared to standard ED or CED frames, making it suitable for locations closer to the power source where potential fault currents are elevated.

Technical Parameters

Product Advantages

• High Interrupting Capacity: Capable of safely clearing fault currents up to 65 kA at 240V, protecting downstream infrastructure from catastrophic thermal and mechanical damage.
• Proven Reliability: The Sentron series thermal-magnetic mechanism is a time-tested industry standard, offering dependable operation without complex electronic calibration.
• Compact FD Frame Design: Delivers a substantial 250A capacity within a relatively compact footprint, optimizing panel board space.
• Flexible Application: Rated for both AC and DC systems, allowing it to be standardized across different types of power distribution networks.

Important Considerations & Precautions

• Lug Selection: This breaker is typically supplied without terminal lugs unless specified. Ensure you select the correct mechanical or compression lugs compatible with your specific wire gauge (AWG/kcmil) and material (Al/Cu).
• Thermal Environment: Because it uses a thermal trip element, ambient temperature affects performance. If installed in an enclosure exceeding 40°C, the breaker must be derated according to Siemens calibration curves.
• Non-Interchangeable Trip: The 250A trip unit is fixed. If your system load requirements change significantly in the future, the entire breaker unit must be replaced (unlike frames with interchangeable trip units).
• Mounting Orientation: Can be mounted vertically or horizontally without affecting the trip characteristics, but proper ventilation clearance must be maintained.

Product Applications

The FXD63B250 is widely utilized as a main or large branch feeder breaker in heavy commercial and industrial settings:

• Electrical Panelboards: Serving as the main incoming breaker or a heavy branch breaker for sub-panels.
• Motor Control Centers (MCCs): Providing upstream branch circuit protection for large motor starters and variable frequency drives (VFDs).
• Industrial Machinery: Serving as the main service disconnect inside large machine control enclosures.
• Commercial Buildings: Protecting HVAC chillers, large pumps, and lighting distribution circuits in hospitals, high-rises, and data centers.

Shipping Port: Xiamen, China

Payment: Bank of Chicago, Bank of Singapore

Express cooperation: fedex, DHL, UPS and your express account

Service: Professional Sales provides 24 hours /7 days online service

Please make an inquiry for more models：