Littelfuse LLNRK02.5 - Littelfuse LLNRK and LLSRK series POWR-PRO™ fuses provide superior overload and short circuit protection for service entrance, main, feeder and general-purpose branch circuits up to 600 amperes. LLNRK/LLSRK series fuses can be installed in existing Class H fuse blocks to upgrade systems containing lower interrupting rating Class H one-time or renewable fuses.
Littelfuse

LLNRK02.5

Alternate Item Number: LNRK02.5T

UPC: 079458330434

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Overview

The **Littelfuse LLNRK02.5 POWR-PRO™ fuse** (SKU: LLNRK02.5) from the **LLNRK/LLSRK series** delivers unmatched overload and short-circuit protection for critical electrical systems, including service entrance, main, feeder, and general-purpose branch circuits up to **600 amperes**. Designed for seamless integration into existing **Class H fuse blocks**, this high-performance fuse enables cost-effective system upgrades without the need for full block replacement—a key advantage for industrial facilities, commercial buildings, and utility applications seeking to enhance safety and reliability while maintaining compliance with modern electrical standards. Engineered for demanding environments, the **LLNRK02.5** combines **superior interrupting ratings** with robust construction to withstand extreme fault conditions. Its advanced design ensures rapid response to overcurrent events, minimizing downtime and reducing the risk of equipment damage. Unlike traditional Class H one-time or renewable fuses, which often lack the interrupting capacity required for today’s high-fault systems, the **POWR-PRO™ series** provides a **600A rating** with enhanced thermal and mechanical durability, making it ideal for applications where reliability is non-negotiable. **Key applications** include: - **Service entrance protection** in commercial and industrial facilities - **Main and feeder circuit safeguarding** for distribution panels - **Branch circuit protection** in manufacturing plants, data centers, and healthcare environments - **Upgrades for legacy systems** with lower-rated Class H fuses, ensuring compliance with NEC and IEC standards Industry professionals choose Littelfuse for its **proven track record** in electrical protection solutions. With decades of expertise in fuse technology, Littelfuse designs products that meet the rigorous demands of modern electrical infrastructure. The **LLNRK/LLSRK series** is trusted by engineers, electricians, and facility managers for its **high interrupting rating**, **ease of installation**, and **long-term performance**—critical factors when selecting protective devices for mission-critical systems. Installation is straightforward: the **LLNRK02.5** fits directly into existing **Class H fuse blocks**, eliminating the need for costly retrofits. Its **compact design** and **compatibility** with standard fuse holders ensure a smooth transition, whether upgrading an aging panel or designing a new system. For facilities operating in harsh conditions—such as high temperatures, vibration, or corrosive environments—Littelfuse’s **industry-leading durability** provides peace of mind, reducing maintenance costs and extending equipment lifespan. Selecting the right fuse involves balancing **interrupting capacity**, **response time**, and **compliance requirements**. The **LLNRK02.5** excels in all three areas, offering a **600A rating** with **superior fault interruption** to protect against both overloads and short circuits. Its **time-current characteristics** are optimized for modern electrical loads, ensuring precise tripping under fault conditions while maintaining stability during normal operation. For engineers and procurement teams, Littelfuse’s **LLNRK02.5** represents a smart investment in **safety, efficiency, and future-proofing**. By replacing outdated Class H fuses with this **high-performance alternative**, facilities can achieve **enhanced protection**, **reduced downtime**, and **long-term cost savings**—all while meeting the latest electrical safety codes. Whether upgrading a single panel or outfitting an entire industrial complex, the **POWR-PRO™ series** delivers the reliability and performance required for today’s complex electrical systems.
  • 600A rated for service entrance, main, feeder, and branch circuits
  • Superior overload and short-circuit protection
  • Compatible with existing Class H fuse blocks for easy upgrades
  • High interrupting rating for demanding industrial applications
  • Trusted Littelfuse POWR-PRO™ series for reliable performance

Specifications

Amperage Rating
2.5 AMP
Application
All general purpose circuits
Brand Name
Littelfuse
Current Rating
600 A
Series
LLNRK/LLSRK
Special Features
Time-Delay
Standard
Standard 248-12 UL Listed/CSA
Sub Brand
LLNRK Series
Type
Class RK1
Voltage Rating
600 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 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 Block 1500VAC 1500VDC 400A 1-Pole Stud M8

1SCM8

Fuse Block 1500VAC 1500VDC 400A 1-Pole Stud M8
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 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.