Littelfuse LLNRK1.25 - 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

LLNRK1.25

Alternate Item Number: LNRK1.25T

UPC: 079458330342


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Overview

The Littelfuse LLNRK1.25 POWR-PRO™ fuse (SKU: LLNRK1.25) is engineered to deliver exceptional overload and short circuit protection across a wide range of critical electrical applications. Designed for industrial and commercial environments, this high-performance fuse is suitable for service entrance, main distribution panels, feeder circuits, and general-purpose branch circuits, capable of handling currents up to 600 amperes. Its robust design ensures reliable operation in demanding conditions, safeguarding valuable equipment and personnel from electrical faults. A key advantage of the LLNRK1.25 is its seamless integration with existing electrical infrastructure. This fuse series is specifically designed for compatibility with standard Class H fuse blocks. This feature provides an invaluable upgrade path for facilities currently utilizing lower interrupting rating Class H one-time or renewable fuses. By simply replacing older fuses with the Littelfuse LLNRK1.25, users can significantly enhance their system's safety and protection capabilities without the need for costly and time-consuming fuse block replacements. This makes it an economically sensible and technically superior solution for modernizing electrical distribution systems. The Littelfuse POWR-PRO™ series represents Littelfuse's commitment to providing advanced fuse technology. The LLNRK1.25 embodies this by offering a high interrupting rating, crucial for preventing catastrophic damage during severe short circuit events. This level of protection is paramount in industries such as manufacturing, data centers, utilities, and commercial buildings where system uptime and safety are non-negotiable. The fuse's construction is optimized for durability and long-term performance, ensuring consistent protection over its service life. Key features and benefits of the Littelfuse LLNRK1.25 include: * **Superior Protection:** Provides robust overload and short circuit protection up to 600A. * **Class H Compatibility:** Easily upgrades existing Class H fuse blocks, offering a cost-effective modernization solution. * **High Interrupting Rating:** Essential for safeguarding against severe fault conditions and preventing equipment damage. * **Reliable Performance:** Engineered by Littelfuse, a trusted leader in circuit protection, for dependable operation. * **Versatile Application:** Ideal for service entrance, main, feeder, and general-purpose branch circuits. When selecting fuses for critical applications, professionals prioritize reliability, safety, and compatibility. The Littelfuse LLNRK1.25 POWR-PRO™ fuse meets these demands, offering peace of mind and enhanced operational integrity. Its ability to upgrade existing systems efficiently makes it a preferred choice for electrical engineers, maintenance managers, and system designers looking to bolster their electrical protection strategies. Trust Littelfuse for advanced circuit protection solutions that keep your operations running safely and efficiently.
  • Provides superior overload and short circuit protection up to 600 amperes.
  • Designed for compatibility with existing Class H fuse blocks, enabling easy system upgrades.
  • Ideal for service entrance, main, feeder, and general-purpose branch circuit applications.
  • Engineered by Littelfuse, a trusted leader in circuit protection, for reliable performance.
  • Enhances safety and system efficiency by offering a high interrupting rating.

Specifications

Amperage Rating
1.25 Amp
Application
All general purpose circuits
Brand Name
Littelfuse
Connection Type
Fuse Block
Current Rating
600 A
Current Rating
1.25 A
Material
Silver
Mounting Type
Class H fuse block compatible
Series
LLNRK/LLSRK
Series
POWR-PRO™ 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

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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.