Overview
The Littelfuse NLN100 is a general-purpose, one-time fast-blow cartridge fuse rated 100A at 250VAC/250VDC. Part of Littelfuse’s POWR-GARD® NLN series, this Class K5 fuse delivers a 50,000A interrupting rating, making it suitable for residential, commercial, and light industrial applications where short-circuit currents remain below 50kA. The NLN100 provides economical protection for circuits with minimal motor loads and is a direct upgrade from legacy Class H designs.
Key Features
- 50,000A interrupting rating (Class K5) — higher protection margin than Class H (10,000A)
- Fast-blow, single-element design for immediate fault response
- Knife-blade terminal for standard fuse holders
- One-time use with non-indicating body
- Suitable for residential, commercial, and smaller industrial circuits
- Economical solution for general-purpose applications without significant motor loads
Technical Specifications
- Current Rating: 100 Amperes
- Voltage Rating: 250VAC / 250VDC
- Interrupting Rating: 50,000A AC RMS (Class K5)
- Class Designation: K5 (UL-listed)
- Type: Fast-blow, one-time (non-indicating)
- Fuse Shape: Cartridge (tubular)
- Body Dimensions: 1-1/16 inch diameter × 5-7/8 inch length
- Terminal Type: Knife blade (for standard fuse holders)
- Speed Rating: Fast Blow
- Frequency: 50/60 Hz
- Series: POWR-GARD® NLN
- UL Listed: Yes
Typical Applications
The NLN100 protects:
- General-purpose residential and commercial branch circuits
- Feeder circuits in facilities with short-circuit currents below 50kA
- Non-motor loads and resistive heating circuits
- Equipment where lowest initial cost is prioritized and motor protection is not required
- Retrofit installations replacing legacy Class H fuses
Compatibility & Replacements
Compatible With
- Standard cartridge fuse holders rated 250VAC
- Electrical panels and disconnect switches designed for knife-blade cartridge fuses
- General-purpose residential, commercial, and light industrial branch and feeder circuits
- Systems rated up to 250VAC with fuse-based overcurrent protection
Replaces / Drop-In Replacement For
- All Class H 100A fuses (10,000A interrupting rating) — NLN provides superior 50,000A capacity in the same cartridge form
- Legacy Class H general-purpose fuses in existing installations
- Other generic 100A/250VAC one-time cartridge fuses with compatible dimensions
Works With
- Littelfuse POWR-GARD® and POWR-PRO® fuse families
- Standard 250VAC distribution equipment and circuit breaker panels
- Residential and commercial electrical codes (NEC, IEC compliance)
- For higher short-circuit applications or time-delay needs, consider Littelfuse FLNR (Class RK5, 200kA) or RK1 series fuses



