Littelfuse FLNR040.TXID Class RK5 40A 250V Time Delay Fuse

Product Description

The LITTELFUSE FLNR040.TXID is a Class RK5 time-delay, indicating fuse rated for 40 amps at 250 volts. It is a current-limiting fuse with high interrupting capacity, designed to protect electrical circuits from overcurrent conditions while providing a visible indication when the fuse has operated. The time-delay characteristic allows the fuse to ride through brief, harmless current surges without nuisance tripping, making it well suited for circuits where transient loading is a normal part of operation. Licensed electricians install this fuse in industrial, commercial, and residential distribution equipment.

This fuse is appropriate for use in service entrance switches, switchboard main and feeder switches, motor control center mains and motor branch circuits, individually fused combination motor controllers, and distribution panelboards. It is also suitable for control circuits, street lighting, high-intensity discharge lighting, and computer power circuits where high inrush currents are not present. The aluminum construction contributes to its durability in panel and switchboard environments.

Key Features

• Class RK5 current-limiting design with high interrupting capacity
• Time-delay action tolerates normal transient surges without nuisance tripping
• Visual indicating feature signals fuse operation for faster troubleshooting
• Rated 40 amps at 250 volts for broad panelboard and switchboard applications
• Aluminum construction for reliable performance in distribution equipment
• UL Listed for use in service entrance, motor control, and distribution applications

Compatibility

Suitable for service entrance switches, switchboard main and feeder switches, motor control center mains and motor branch circuits, individual fused combination motor controllers, and distribution panelboards as stated by the manufacturer.

Installation Notes

Installation must be performed by a qualified, licensed electrician in accordance with the National Electrical Code (NEC) and all applicable local codes. Always de-energize and lockout/tagout the circuit before removing or installing fuses. Verify that the replacement fuse matches the required amperage, voltage rating, and fuse class before installation. Do not install a fuse with a higher amperage rating than the circuit is designed to carry.