Littelfuse LLNRK025 - 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

LLNRK025

Alternate Item Number: LNRK025.T

UPC: 079458330724


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Overview

Upgrade your electrical protection with the **Littelfuse LLNRK025 POWR-PRO™ fuse**, a high-performance solution designed for service entrance, main, feeder, and general-purpose branch circuits up to 600 amperes. Part of the trusted **LLNRK/LLSRK series**, this fuse delivers **superior overload and short circuit protection**, ensuring the safety and reliability of critical industrial and commercial electrical systems. Engineered for seamless integration, the LLNRK025 is fully compatible with existing **Class H fuse blocks**, allowing for efficient system upgrades without the need for costly infrastructure replacements. This makes it an ideal choice for facilities looking to enhance protection while maintaining operational continuity. The **POWR-PRO™ series** from Littelfuse is renowned for its robust construction and high interrupting rating, providing unmatched performance in demanding environments. Whether you're managing a manufacturing plant, data center, hospital, or large commercial building, these fuses offer the reliability required to safeguard sensitive equipment and prevent costly downtime. The LLNRK025 is particularly valuable for facilities transitioning from lower-rated Class H one-time or renewable fuses, as it meets modern electrical standards while simplifying the upgrade process. Key features of the **Littelfuse LLNRK025** include: - **High interrupting rating** for superior short circuit protection, reducing the risk of catastrophic failures. - **Seamless compatibility** with existing Class H fuse blocks, eliminating the need for infrastructure overhauls. - **Enhanced overload protection** to safeguard critical circuits and connected equipment. - **Durable construction** designed for long-term reliability in harsh industrial environments. - **Compliance with modern electrical standards**, ensuring your system meets or exceeds safety regulations. Industries that benefit from the **LLNRK025** include manufacturing, healthcare, data centers, commercial real estate, and utilities. Electrical contractors and facility managers rely on Littelfuse’s reputation for innovation and quality when selecting protective devices, as the brand is synonymous with precision engineering and dependable performance. By choosing the LLNRK025, you’re not just upgrading a fuse—you’re investing in the long-term safety and efficiency of your electrical infrastructure. Littelfuse’s **POWR-PRO™ series** has been a trusted name in circuit protection for decades, with a global presence and a commitment to advancing electrical safety standards. The LLNRK025 exemplifies this legacy, offering a cost-effective, high-performance solution for professionals who demand the best in circuit protection. Whether you’re retrofitting an older system or designing a new installation, the LLNRK025 provides the peace of mind that comes with superior engineering and unwavering reliability.
  • 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 enhanced safety in industrial applications
  • Trusted Littelfuse POWR-PRO™ series for reliable circuit protection

Specifications

Amperage Rating
25 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
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 Modulostar® Size 10x38 IEC 690VAC 690VDC 3-Pole IP20

E1062696

Fuse Holder Modulostar® Size 10x38 IEC 690VAC 690VDC 3-Pole IP20
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
9F61 Size B Clips 1.6in

9F61BWW460

9F61 Size B Clips 1.6in
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.

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.