Littelfuse, Inc. (Chicago, IL) 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. Features include:

• High-energy applications like 3-phase power supplies, inverters, and ballasts.
• Lower interrupting rating ( I2t) and faster tripping; this ensures the short-circuit and over-current fault in the PSU is protected.
• Current ratings as high as 16A in a 5x20mm footprint, which saves space on the printed circuit board.
• 420V AC rating which makes the 487 Series suitable for high-power 3-phase applications, inverters, and ballasts.
• 420V DC rating which makes the 487 Series an optimal choice for high-voltage DC applications in datacenter power distribution, telecom, and intelligent commercial building applications.

For more information on the 487 Series Fuse, visit