Littelfuse L70S Series Very Fast-Acting Semiconductor Fuse, 700VAC/650VDC

Littelfuse L70S Series Very Fast-Acting Semiconductor Fuse, 700VAC/650VDC

The Littelfuse L70S Series Very Fast-Acting Semiconductor Fuse delivers extremely fast-acting, current-limiting protection for solid-state semiconductor devices, available in ampere ratings from 70A to 300A. Rated 700VAC and 650VDC, this Very Fast-Acting (FF) fuse is engineered for supplementary protection of SCRs, diodes, thyristors, triacs, transistors, and similar solid-state devices used in variable speed drives, power rectifiers, UPS systems, DC power supplies, and other power electronic equipment. Littelfuse-developed metallurgical, polymer, and materials technology delivers accuracy, consistent quality, and predictable performance, and the L70S Series is UL Recognized for use in UL listed equipment.

Key Features

• Ampere Rating Range: Available from 70A to 300A, allowing precise overcurrent protection selection for a range of high-power semiconductor circuits.
• Dual Voltage Rating: Rated 700VAC and 650VDC, supporting both AC and DC semiconductor protection applications.
• Very Fast-Acting (FF) Opening: Extremely fast-acting, current-limiting design with no time delay for sensitive solid-state devices.
• Interrupting Rating: Rated 20000A@650VDC (AC: 200 kAIC / DC: 20 kAIC) for reliable interruption of present and future overcurrents.
• Extremely Current-Limiting: Low I2t and peak let-through currents meet most semiconductor manufacturer requirements.
• L70S Series Engineering: Built using Littelfuse-developed metallurgical, polymer, and materials research plus mathematical modeling and computerized statistical analysis for consistent, predictable performance.
• UL Recognized: May be used to provide supplementary protection in UL listed equipment.

Certifications & Compliance

• UL Recognized

Technical Specifications

• Refer to manufacturer documentation for complete technical specifications.

Typical Applications

• Variable Speed Drives
• Power Rectifiers
• UPS Systems and DC Power Supplies
• Protection of SCRs, Diodes, Thyristors, Triacs, and Transistors
• Solid-State Device Protection Circuits
• Electronic Equipment Requiring Fast-Acting, Current-Limiting Fuses

Why Littelfuse?

Littelfuse engineers apply advanced metallurgical, polymer, and materials research along with mathematical modeling and computerized statistical analysis to every L70S Series fuse, delivering accuracy, consistent quality, and reliability. With extremely current-limiting performance and UL Recognized status across the 70A to 300A range, the L70S Series provides dependable, code-compliant overcurrent protection for demanding semiconductor and power electronics applications.