Overview
The Littelfuse FLSR40ID is a Class RK5, time-delay indicator fuse rated for 40 amps at 600 volts AC. This dual-element cartridge fuse combines fast short-circuit protection with time-delay overload capability, making it ideal for motor circuits and general-purpose applications. The integrated indicator feature provides visual confirmation of blown fuses, eliminating guesswork during maintenance and reducing production downtime.
Key Features
- Dual-Element Design: Fast-acting element for short-circuit protection combined with time-delay element for handling motor inrush currents
- Visual Indication: Blown fuse indicator allows quick visual inspection without continuity testing
- Class RK5 Rating: 200,000 amps RMS AC interrupting capacity at 600V
- Time-Delay (Slow-Blow): Tolerates temporary overloads common in motor and inductive circuits
- Cartridge Style: Compact ferrule/cartridge construction fits standard fuse holders
- UL and CSA Certified: Meets UL Standard 248-12 and CSA requirements for industrial and commercial use
Technical Specifications
- Ampere Rating: 40A
- Voltage Rating: 600V AC / 300V DC
- Fuse Class: RK5 (General Purpose)
- Type: Dual-Element Time-Delay (Slow-Blow)
- Interrupting Rating: 200 kA RMS AC @ 600V; 20 kA DC @ 300V
- Construction: Cartridge (Ferrule)
- Indication: Yes (Blown Fuse Indicator)
- Series: FLSR_ID (Powr-Gard)
- Approvals: UL E81895, CSA LR29862, Federal Spec WF-1814
Typical Applications
- Motor branch circuits and motor control centers
- Service entrance and switchboard mains
- Distribution panelboards and feeder circuits
- Industrial control panels
- General-purpose circuits with inductive loads
- Equipment requiring coordinated short-circuit and overload protection
Compatibility & Replacements
Compatible With
- Standard cartridge fuse holders rated for Class RK5 fuses
- Any circuit designed for 40A, 600V time-delay protection
- Motor circuits with dual-element time-delay requirements
- Industrial control systems and electrical distribution equipment
Replaces / Drop-In Replacement For
- Littelfuse FLSR-40 (non-indicating version)
- Other 40A, 600V Class RK5 dual-element time-delay indicator fuses
Works With
- Class RK5 fuse blocks and holders
- Electrical distribution systems rated for 600V AC service
- Motor control centers (MCC) and branch circuit panels
- Industrial switchgear and panelboards
