Overview
The Littelfuse FLSR100 is a Class RK5 dual-element time-delay fuse rated at 100 amperes, 600VAC/300VDC. The FLSR100 features knife-blade-style construction and is designed for superior dual-element time-delay protection across industrial and commercial electrical circuits.
Key Features
- Time-Delay (Slow-Blow) Design: Provides time-delay protection, allowing inrush currents to settle before fuse operation
- Dual-Element Construction: FLSR series are the most widely used class of RK5 fuses for overcurrent protection
- High Interrupting Rating: 200,000 amp symmetrical interrupting capacity at 600VAC
- Motor Circuit Protection: Excellent protection for circuits containing motors
- Rejection-Style Terminal: Knife-blade design prevents misapplication in rejected-type fuseholders
- UL and CSA Certified: cUL certification and CSA compliance
Technical Specifications
| Ampere Rating | 100 A |
| Voltage Rating | 600 VAC, 300 VDC |
| Fuse Class | Class RK5 |
| Speed | Time Delay (Dual Element) |
| Terminal Style | Knife Blade (Rejection) |
| Interrupting Rating | 200 kA at 600 VAC, 20 kA at 300 VDC |
| Dimensions | 1.311″ Diameter × 7.874″ Length |
| Weight | 0.68 oz |
| Certifications | UL, CSA, CE |
| Series | FLSR |
| Alternative Part Numbers | FLSR100A, FLSR100.V, FLSR 100 Amp |
Typical Applications
- Motor starter circuits and branch protection
- Industrial machinery feeder circuits
- HVAC systems and compressor loads
- General industrial control circuits with high inrush currents
- Low-voltage DC backup power systems (up to 300VDC)
Compatibility & Replacements
Compatible With
- Class RK5-rated fuseholders and disconnect switches
- Industrial control panels rated for 600VAC service
- Motor starters and motor feeder circuits
- Electrical distribution equipment with rejection-style terminals
Replaces / Drop-In Replacement For
- FLSR100A
- FLSR100.V
- FLSR 100 Amp (all variants within Class RK5, 600VAC, 100A specification)
Works With
- UL Class RK5-compliant equipment and fuseholders
- Motor protection and thermal overload systems
- Industrial control and automation equipment
- Electrical distribution and panel equipment certified for 600VAC service
