Overview
The Littelfuse KLNR50 is a Class RK-1 fast-acting current limiting fuse engineered for reliable overcurrent protection in industrial and commercial electrical systems. KLNR series RK1 fast-acting fuses feature a single-element silver link design that enables fast-acting overload and short-circuit protection. With a 200,000 A.I.R. (Ampere Interrupting Rating), this fuse reliably interrupts all overcurrents up to 200,000 amperes.
Key Features
- Extremely current-limiting design often permits use of readily available, less costly equipment
- Fast-acting protection for surge-sensitive components such as variable speed drives and rectifiers
- 200,000 A.I.R. rating minimizes need for short circuit calculations
- Single-element silver link construction for fast response to overcurrent events
- UL listed Class RK-1 certified for reliable equipment protection
Technical Specifications
- Series: KLNR (fast-acting)
- Fuse Class: RK-1
- Current Rating: 50A
- Interrupting Rating (A.I.R.): 200,000 amperes
- Fuse Type: Current Limiting
- Element Design: Single-element silver link
- Response: Fast-acting
- UL Standard: UL Class RK1
Typical Applications
- Input and output fuses for variable frequency drives (VFDs)
- Protection for rectifier circuits and power conversion equipment
- Semiconductor component protection in industrial control panels
- Motor control centers and distribution equipment requiring current-limiting fuses
- Equipment where short-circuit current limiting is required without oversizing
Compatibility & Replacements
Compatible With
- UL Class RK-1 rated electrical equipment and panelboards
- Motor control centers and load centers rated for Class RK-1 fuses
- Surge-sensitive industrial equipment including drives and power supplies
- Standard Class RK-1 fuse holders and clips
Replaces / Drop-In Replacement For
- Other KLNR50 Class RK-1 fuses from competing manufacturers meeting UL specifications
- Verify compatibility with your system integrator or equipment manufacturer before ordering to ensure application appropriateness
Works With
- UL Class RK-1 rated electrical distribution systems
- Standard electrical panelboards and switchgear
- Variable frequency drives and soft starters
- Industrial power systems with short-circuit requirements up to 200 kA








