Littelfuse FLNR090 - FLNR090 is a Class RK5 fuse with an ampere rating of 90 and knife-blade-style construction.
Littelfuse

FLNR090

Alternate Item Number: FLNR090.V

UPC: 079458150810


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Overview

The Littelfuse FLNR090 Class RK5 90A knife-blade fuse is a premium industrial-grade overcurrent protection device engineered for high-performance applications in power distribution, motor control, and critical electrical systems. Designed with Littelfuse’s renowned precision and reliability, this fuse delivers robust circuit protection in environments where operational continuity and safety are non-negotiable. The Class RK5 classification ensures compliance with stringent industry standards, including UL 248 and IEC 60269, making it a trusted solution for North American and international markets alike. Engineered for demanding industrial applications, the FLNR090 features a knife-blade-style construction that simplifies installation and maintenance in panelboards, switchgear, and motor control centers. Its 90-ampere rating provides precise overcurrent protection, preventing damage to sensitive equipment while minimizing downtime during fault conditions. The fuse’s high interrupting rating ensures reliable operation even in high-fault-current scenarios, a critical requirement in modern industrial facilities where power quality and system integrity are paramount. Typical applications for the Littelfuse FLNR090 include: - **Motor control panels** – Protecting motors from overloads and short circuits in manufacturing plants, HVAC systems, and conveyor systems. - **Power distribution systems** – Safeguarding transformers, busways, and branch circuits in commercial and industrial buildings. - **Machine tool applications** – Providing reliable protection for CNC machines, presses, and automated production lines. - **Renewable energy systems** – Integrating into solar and wind power distribution systems where consistent overcurrent protection is essential. - **Data centers and critical infrastructure** – Ensuring uptime and preventing catastrophic failures in high-availability electrical systems. Selecting the right fuse for industrial applications requires careful consideration of factors such as interrupting rating, coordination with upstream protective devices, and environmental conditions. The FLNR090’s knife-blade design allows for secure, low-resistance connections, reducing the risk of overheating and ensuring long-term reliability. Its compact form factor optimizes panel space, making it an ideal choice for retrofit projects or new installations where efficiency and scalability are priorities. Littelfuse, a global leader in circuit protection solutions, has been delivering trusted products for over a century. The company’s Class RK5 fuses, including the FLNR090, are widely recognized for their durability, precision, and adherence to global safety standards. Professionals in electrical engineering, maintenance, and facility management consistently rely on Littelfuse for solutions that balance performance, compliance, and cost-effectiveness. Whether deployed in heavy manufacturing, utilities, or commercial infrastructure, the FLNR090 exemplifies Littelfuse’s commitment to innovation and excellence in circuit protection. For industrial professionals seeking a high-performance, code-compliant fuse solution, the Littelfuse FLNR090 Class RK5 90A knife-blade fuse stands as a benchmark in reliability and safety. Its robust design, ease of installation, and proven performance make it a go-to choice for protecting critical electrical systems across diverse industries.
  • Class RK5-rated for compliance with UL 248 and IEC 60269 standards
  • 90A ampere rating for precise overcurrent protection in industrial systems
  • Knife-blade construction for secure, low-resistance connections
  • High interrupting rating for reliable operation in high-fault-current environments
  • Compact design optimizes panel space in retrofit and new installations

Specifications

Application
General Purpose
Brand Name
Littelfuse
Connection Type
Knife-blade
Current Rating
90 A
Series
FLNR
Size
Knife-Blade Style
Special Features
Time-Delay
Standard
Standard 248-12 UL Listed/CSA
Sub Brand
POWR-GARD FLNR Series
Type
Class RK5
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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

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

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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.