Littelfuse L50S Series Very Fast-Acting Semiconductor Fuse, 500V

Littelfuse L50S Series Very Fast-Acting Semiconductor Fuse, 500V

The Littelfuse L50S Series High-Speed Semiconductor Fuse delivers supplementary protection for SCRs, diodes, thyristors, triacs, transistors, and other solid-state devices used in variable speed drives, power rectifiers, UPS systems, and DC power supplies. Engineered with Littelfuse-developed metallurgical, polymer, and materials technology, the L50S Series is rated 500VAC / 450VDC and is available in ampere ratings from 50A to 200A to match a wide range of solid-state protection needs. Each fuse in the series features a Very Fast-Acting (FF) opening characteristic for extremely current-limiting, no-time-delay interruption, and carries UL Recognition for supplementary protection in UL listed equipment.

Key Features

• Ampere Rating Range: Available from 50A to 200A to size protection for varying semiconductor load requirements.
• Voltage Rating: 500VAC / 450VDC for use across AC and DC solid-state equipment circuits.
• Very Fast-Acting (FF) Opening: No time-delay, current-limiting operation protects sensitive semiconductor devices from damaging fault currents.
• High Interrupting Capability: Interrupting ratings up to 20000A@450VDC deliver reliable interruption of overcurrents to meet demanding system requirements.
• Extremely Current Limiting: Low I2t and peak let-through currents meet the requirements of most semiconductor devices.
• UL Recognized: High-speed fuses may be used to provide supplementary protection in UL listed equipment.
• Purpose-Built Design: Designed specifically for supplementary protection of solid-state semiconductor devices rather than general branch-circuit use.

Certifications & Compliance

• UL Recognized

Technical Specifications

• Refer to manufacturer documentation for complete technical specifications.

Typical Applications

• Variable Speed Drives requiring fast semiconductor protection
• Power Rectifiers and DC Power Supplies
• UPS Systems and Standby Power Equipment
• Protection of SCRs, Diodes, Thyristors, Triacs, and Transistors
• Solid-State and Electronic Power Equipment

Why Littelfuse?

Littelfuse engineers apply advanced metallurgical, polymer, and materials research along with mathematical modeling and computerized statistical analysis to every fuse in the L50S Series. The result is consistent quality, accuracy, and predictable performance backed by UL Recognition, making the L50S Series a dependable choice for protecting critical semiconductor devices such as SCRs, diodes, thyristors, and triacs across variable speed drives, rectifiers, and UPS systems.