Littelfuse L50S125 Semiconductor Fuse 125A 500V

Product Description

The LITTELFUSE L50S125 is a semiconductor protection fuse rated at 125 amps and 500 volts, designed to provide fast-acting overcurrent protection for solid-state power components. Semiconductor fuses are engineered with extremely low I2t values and rapid clearing times, limiting fault current before it can damage SCRs, IGBTs, diodes, and similar devices. This fuse is installed by licensed electricians and power electronics technicians working on industrial drives, power conversion equipment, and motor control centers where standard fuses are too slow to protect sensitive semiconductor junctions.

The L50S125 is suited for industrial and commercial electrical applications where semiconductor devices require dedicated overcurrent protection. Typical installation scenarios include variable frequency drives (VFDs), rectifier assemblies, DC bus circuits, and power conditioning equipment. The 500-volt rating makes it appropriate for standard 480-volt AC distribution systems common in commercial and light industrial facilities.

Key Features

• 125-amp continuous current rating for semiconductor circuit protection
• 500-volt AC rating compatible with 480-volt industrial distribution systems
• Fast-acting current-limiting design minimizes I2t let-through to protect downstream semiconductor devices
• Purpose-built for solid-state power electronics including VFDs, rectifiers, and inverters

Compatibility

Designed as an OEM-style replacement semiconductor fuse for industrial power electronics equipment requiring a 125-amp, 500-volt current-limiting fuse of the L50S series form factor.

Installation Notes

Installation must be performed by a qualified electrician in accordance with the National Electrical Code (NEC) and applicable local codes. De-energize and lock out the circuit at the upstream disconnect before removing or installing any fuse. Verify that the replacement fuse matches the original current rating, voltage rating, and physical form factor before installation. Do not substitute a general-purpose or time-delay fuse where a semiconductor-type fuse is specified, as doing so will not provide adequate protection for solid-state components.

Technical Specifications

• Current Rating: 125 amps
• Voltage Rating: 500 volts
• Fuse Type: Semiconductor (current-limiting, fast-acting)
• UPC: 07945885125

Standard Information

• Brand: LITTELFUSE
• Manufacturer Part Number: L50S125