Fast-Acting 5 x 20 mm Fuse carries both 420 Vac and Vdc ratings.

Press Release Summary:

Offered in cartridge or axial-leaded versions with current ratings to 16 A, 487 Series ensures optimal coordination between PSU and electrical circuit breaker panel during short-circuit and over-current faults to protect telecom and datacenter equipment. Air circuit breaker trips before fuse opens when circuit is exposed to short-circuit condition. Installed in PSU, fuse opens faster than circuit breaker, removes problematic PSU from branch circuit, and keeps branch circuit live without cutoff.

Original Press Release:

Littelfuse Introduces First Fast-Acting Fuse in Its 5x20mm Fuse Family with Both 420V AC and DC Ratings

Protects high-voltage DC power grid in datacenters, telecom, and intelligent commercial buildings

CHICAGO — Littelfuse, Inc., the global leader in circuit protection, has introduced the 487 Series Fuse, the first fast-acting fuse from its 5x20mm fuse family with both 420V AC and 420V DC  ratings. In contrast with existing fuse solutions that cannot meet high-voltage and short-circuit test requirements, the 487 Series protects telecom power supply units and datacenter server power applications where a high-voltage DC interrupting rating is required. This compact ceramic body fuse is designed to ensure the best coordination between a power supply unit (PSU) and an electrical circuit breaker panel during short-circuit and over-current faults. The air circuit breaker trips before the fuse opens when the circuit is exposed to a short-circuit condition. When installed in a PSU, the 487 Series fuse opens faster than the circuit breaker in an electrical panel, removes the problematic PSU from the branch circuit, and keeps the branch circuit live without cutoff.

The 487 Series’ 420VAC characteristics make it well suited for high-energy applications like 3-phase power supplies, inverters, and ballasts. Its 420VDC characteristics make it an optimal choice for a high-voltage DC power grid in datacenters, telecom, and intelligent commercial buildings.

“The new 487 Series Fuse offers an added reliability assurance for telecom power supplies because the fuse opens quickly and safely,” said Roger Huang, product manager for the 487 Series product line. “Its compact 5x20mm footprint saves space on the printed circuit board, which is especially important in high-power applications.”

The 487 Series Fuse offers these key benefits:

Lower interrupting rating ( I2t) and faster tripping; this ensures the short-circuit and over-current fault in the PSU is protected because the 487 Series fuse in the electrical panel opens rather than the circuit breaker, which would cause an power outage in the entire branch circuit.

Current ratings as high as 16A in a 5x20mm footprint, which saves space on the printed circuit board.

420V AC rating makes the 487 Series suitable for high-power 3-phase applications, inverters, and ballasts.

420V DC rating makes the 487 Series an optimal choice for high-voltage DC applications in datacenter power distribution, telecom, and intelligent commercial building applications.


The 487 Series Fuse is available in quantities of 1,000 (bulk packaging) in either cartridge or axial-leaded versions. Sample requests can be placed through authorized Littelfuse distributors worldwide. For a listing of Littelfuse distributors, please visit

For More Information

Additional information is available on the 487 Series product page and datasheet. If you have technical questions, please contact: Roger Huang, Product Manager,

About Littelfuse

Founded in 1927, Littelfuse is the world leader in circuit protection with growing global platforms in power control and sensing. The company serves global customers in the electronics, automotive and industrial markets with technologies including fuses, semiconductors, polymers, ceramics, relays and sensors. Littelfuse has over 8,000 employees in more than 35 locations throughout the Americas, Europe and Asia. For more information, please visit the Littelfuse website:

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