Authorized Littelfuse Distributor
Littelfuse NLN400 - NLN series fuses provide low cost protection for general-purpose feeder and branch circuits when available short circuit currents are less than 50,000 amperes. They replace all Class H fuses which have only a 10,000 ampere interrupting rating. They are suitable for use in many residential and smaller commercial and industrial applications. NLKP series fuses are Canadian “Code” fuses specifically designed to meet Canadian Electrical Code Type P fuse requirements for residential use. They have a 10,000 ampere interrupting rating. However, to obtain the added benefits of time-delay, current-limitation, and higher interrupting rating, consider the use of POWR-PRO™ IDSR Indicator™ fuses for circuits between 250 and 600 volts. The user gets all the benefits of time-delay RK5 fuses plus the added benefits of a n indicating fuse that tells when it has opened. Complete information on these fuses may be found in the POWR-PRO™ section of this catalog. For circuits up to 250 volts, see FLNR fuses in this section of the catalog.

Littelfuse NLN400 NLN series fuses provide low cost protection for general-purpose feeder and branch…

Alternate Item Number: 0NLN400.X

UPC: 079458360936


Documents & Media
BrochureTechnical BulletinTechnical DrawingSpecification Sheet

Contact for Pricing

Call +1 (262) 252-1600 (toll-free 877-268-3700) or email [email protected] for pricing and availability.

Overview

The Littelfuse NLN400 fuse (SKU: NLN400) delivers cost-effective overcurrent protection for general-purpose feeder and branch circuits in residential, small commercial, and light industrial applications. Rated for 250/600 VAC, this one-time fuse provides a 50,000-ampere interrupting rating (IR), replacing outdated Class H fuses limited to 10,000A IR. The NLN400 is engineered for circuits where available short-circuit currents are below 50,000 amperes, offering superior safety and reliability at a lower cost than specialized fuses. The NLN series is ideal for general-purpose protection in environments requiring dependable, low-cost solutions without the need for time-delay or current-limiting features. For applications demanding time-delay operation, current limitation, or higher interrupting ratings (250–600V), Littelfuse recommends the POWR-PRO™ IDSR Indicator™ series. For circuits up to 250V requiring Class RK5 protection, the FLNR series is the appropriate choice. The NLN400 is part of Littelfuse’s POWR-GARD® Class K5 fuse family, which includes ampere ratings from 1A to 600A. These fuses are designed for use in panelboards, switchgear, and other distribution equipment where reliable fault protection is critical. The NLN series is a direct replacement for Class H fuses, offering enhanced performance without the need for costly upgrades. Technical resources, including time-current (TC) curves and CAD drawings, are available at littelfuse.com/nln for detailed engineering reference.
  • 250/600 VAC rated for versatile application compatibility
  • 400A current rating for general-purpose feeder/branch circuits
  • 50,000A interrupting rating (IR) for superior fault protection
  • One-time operation design for cost-effective reliability
  • 250 VAC rating with NEMA Type P configuration

Specifications

Application
General Purpose
Brand Name
Littelfuse
Series
NLN
Special Features
Economical/low interrupt
Standard
Standard 248-9 UL Listed/CSA
Sub Brand
POWR-GARD NLN Series
Type
Class K5
Voltage Rating
250 VAC
Fuse Block 600VAC 600VDC Class CC 30A 1/4in Quick Connect / Solder 90 angle screw Knob Panel Mount

GPM-SRR90

Fuse Block 600VAC 600VDC Class CC 30A 1/4in Quick Connect / Solder 90 angle screw Knob Panel Mount
Fuse Block 600VAC 600VDC Class CC 30A 3-Pole Pressure Plate with Reinforced Clip

30323R

Fuse Block 600VAC 600VDC Class CC 30A 3-Pole Pressure Plate with Reinforced Clip
Fuse Holder UltraSafe™ 800VAC 1000VDC UL Fuse size 14x51 1-Pole Visual Indicator Microswitch Pressure Plate IP20

C331156

Fuse Holder UltraSafe™ 800VAC 1000VDC UL Fuse size 14x51 1-Pole Visual Indicator Microswitch Pressure Plate IP20
Fuse Holder Modulostar® Size 10x38 IEC 690VAC 690VDC 3-Pole IP20

E1062696

Fuse Holder Modulostar® Size 10x38 IEC 690VAC 690VDC 3-Pole IP20
POWR-JAW clamps improve the contact between fuse and clip. The unnecessary heat from poor contact due to the loss of spring force in the clips can cause nuisance fuse opening and premature aging of surrounding components. High temperature phenolic resin knob designed for the most severe environments 7 sizes to provide effective coverage. Simple design makes installation easy.

LCC5

POWR-JAW clamps improve the contact between fuse and clip. The unnecessary heat from poor contact due to the loss of spring force in the clips can cause nuisance fuse opening and premature aging of surrounding components. High temperature phenolic resin knob designed for the most severe environments 7 sizes to provide effective coverage. Simple design makes installation easy.
9F61 Size B Clips 1.6in

9F61BWW460

9F61 Size B Clips 1.6in

Frequently Asked Questions

What is the cost of the MROplus program?

The MROplus program is absolutely FREE for customers.

What is the MROplus program and its benefits?

The MROplus program helps customers lower costs, increase plant safety, decrease downtime, and reduce inventory by analyzing fuse inventories and recommending optimal circuit protection.

How can I get my fuse inventory analyzed by MROplus?

Complete a request form with your current fuse inventory and contact your local Littelfuse Sales Representative, 1-800-TEC-FUSE, or [email protected].

How does MROplus help reduce electrical hazards?

It helps upgrade circuit protection to current-limiting types, reducing Hazard Risk Categories (HRC) and allowing workers to wear less Personal Protective Equipment (PPE).

What reports are included in the MROplus Program?

The program includes a Total Cost Savings Report, Consolidated Part Number Report, SKU Reduction Report, and Fuse Performance Summaries.

How do indicating fuses improve productivity?

Indicating fuses provide fast, visible identification of blown fuses, eliminating guesswork and saving time and money on replacements.

Frequently Asked Questions about Littelfuse

What certifications and standards do Littelfuse products comply with?

Littelfuse products are certified to multiple international standards, including UL (Underwriters Laboratories), CSA (Canadian Standards Association), CCC (China Compulsory Certification), and EAC (Eurasian Conformity). Customers can verify specific product certifications by consulting individual product datasheets on Littelfuse.com, which provide comprehensive details about standards compliance for each component.

What industries and applications are Littelfuse products used for?

Littelfuse products are critical for electrical protection and safety across multiple industrial sectors, including manufacturing, automation, power distribution, and electrical control systems. Their comprehensive product portfolio serves industries that require robust electrical protection, including motor and pump applications, solar installations, programmable logic controllers (PLCs), electrical switch panels, and critical infrastructure environments. Key product lines protect against overcurrent, voltage transients, ground faults, and temperature-related electrical risks, ensuring equipment safety and operational reliability.

What technical support does Littelfuse offer?

Littelfuse offers comprehensive technical support through multiple channels. Their Technical Hotline (800-TEC-FUSE) provides direct access to engineers who can help identify issues and recommend solutions. Additionally, Littelfuse offers extensive online Technical Resources at Littelfuse.com, including datasheets, product manuals, whitepapers, application guides, and online design tools. Their experienced product and application engineers also provide step-by-step support from design to installation.

What are the main product lines offered by Littelfuse?

Littelfuse offers comprehensive industrial protection and control product lines, including fuses, fuse holders, protection relays, temperature sensors, and electrical safety components. Their key product categories span surge protective devices, custom OEM products, electrical switch panels, medium voltage fuses, ground-fault protection relays, motor and pump protection devices, and temperature sensors. These products are designed to minimize electrical safety hazards, limit equipment damage, improve productivity, and safeguard personnel from electrical faults.

What are the key features of Littelfuse products?

Littelfuse products feature exceptional circuit protection technologies with key characteristics including UL/IEC safety standard compliance, low internal resistance, and advanced protective capabilities across multiple product lines. Their components provide critical protection for industrial systems, offering features like overcurrent protection, voltage transient suppression, and resettable protection devices with ultra-low resistance and compact designs. Key product lines include fuses, metal oxide varistors (MOVs), TVS diodes, PolySwitch devices, and specialized electronic protection components that enhance system reliability and safety.

What environmental ratings do Littelfuse products have?

Littelfuse products feature comprehensive environmental ratings, including NEMA Type 1, 2, 3, 3R, 4/4X, 12, and 13 certifications, as well as IP65 protection. These ratings ensure superior protection in diverse industrial environments, with an operating temperature range of -40°F to +131°F (-40°C to +55°C). Many products also include UV-stabilized materials and neoprene gaskets for enhanced durability in outdoor and challenging conditions.

What accessories are available for Littelfuse products?

Littelfuse offers several key accessories across their product lines, including fuse holders, voltage monitoring modules, and terminal connectors. Specific accessories include the LPSM003ZXID (indicating) and LPSM003Z (non-indicating) POWR-SAFE Dead Front fuse holders for Class CC and Midget-Style fuses, the VRM6048 voltage monitor accessory module, and female quick connect terminals (P1015 series) in various wire gauge sizes. These accessories are designed to enhance protection, monitoring, and connectivity for Littelfuse electrical components.

What is Littelfuse's warranty policy?

Littelfuse provides comprehensive warranty details on their official website at www.littelfuse.com/warranty. Customers should visit this page to review the specific warranty terms and conditions for their specific product lines. For direct warranty support or questions, customers can contact Littelfuse Technical Support at 1-800-TEC-FUSE or email [email protected].

What communication protocols do Littelfuse products support?

Littelfuse supports a comprehensive range of industrial communication protocols, including PROFIBUS, PROFINET, EtherNet/IP, DeviceNet, Modbus RTU, and CANopen. Our products provide flexible connectivity solutions across multiple industrial automation platforms, enabling seamless integration with various control systems and network architectures.

How are Littelfuse products typically installed?

Littelfuse products are typically installed using specialized mounting hardware like fuse holders, blocks, and panels designed for specific industrial applications. The POWR-SAFE Dead Front holders, for example, provide optimum protection for Class CC and Midget-Style fuses, supporting installations up to 600 VAC/DC. Installation often involves using precision terminals with strain relief, such as 0.25 in. female quick connect terminals, to ensure secure and safe electrical connections in industrial control systems.