Littelfuse FLNR020 - FLNR020 is a Class RK5 fuse with an ampere rating of 20 and cartridge-style construction.
Littelfuse

FLNR020

Alternate Item Number: FLNR020.T

UPC: 079458150711

Documents & Media
BrochureTechnical BulletinTechnical DrawingSpecification Sheet

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Minimum Qty: 10

Multiplier: 10

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Overview

The **Littelfuse FLNR020** is a **Class RK5 cartridge fuse** engineered for **industrial-grade overcurrent protection** in high-demand electrical systems. Designed with a **20 ampere rating** and robust **cartridge-style construction**, this fuse delivers precise and reliable circuit safeguarding in environments where operational continuity is non-negotiable. As part of Littelfuse’s esteemed Class RK5 series, the FLNR020 meets stringent performance standards, ensuring compliance with industrial safety and reliability requirements across global markets. **Key Features and Technical Advantages:** - **High Interrupting Rating:** The FLNR020 is engineered to safely interrupt high fault currents, protecting sensitive industrial equipment from catastrophic damage during short circuits or overload conditions. This is critical in facilities where unplanned downtime can result in significant financial losses. - **Class RK5 Compliance:** Class RK5 fuses are recognized for their superior performance in industrial applications, offering a balance between fast-acting response and high interrupting capacity. This classification ensures the fuse meets UL and other international standards for industrial circuit protection. - **Cartridge-Style Design:** The compact, durable cartridge construction allows for **easy installation and replacement**, minimizing maintenance time and reducing labor costs. The design also ensures secure mounting in panelboards, switchgear, and motor control centers. - **Wide Application Range:** Ideal for use in **power distribution systems, industrial machinery, motor circuits, transformers, and control panels**, the FLNR020 is a versatile solution for facilities in manufacturing, mining, oil & gas, utilities, and commercial buildings. - **Temperature and Vibration Resilience:** Built to withstand harsh industrial environments, the FLNR020 maintains consistent performance under extreme temperatures, humidity, and mechanical stress, ensuring long-term reliability. **Industry Applications and Use Cases:** In **manufacturing plants**, the FLNR020 protects critical machinery such as CNC machines, conveyor systems, and robotic assembly lines from electrical faults that could lead to costly production halts. In **power distribution networks**, it safeguards transformers and switchgear, preventing cascading failures that could disrupt entire facilities. For **data centers and telecom installations**, the fuse provides reliable protection for sensitive electronic equipment, ensuring uptime and data integrity. Additionally, in **oil and gas facilities**, where explosive atmospheres are a concern, the FLNR020’s robust construction and high interrupting rating make it a trusted choice for compliance with safety regulations like ATEX and IECEx. **Selection and Installation Best Practices:** When selecting a fuse for industrial applications, professionals consider factors such as **interrupting rating, response time, and environmental conditions**. The FLNR020 excels in all these areas, making it a preferred choice for engineers and maintenance teams. Installation is straightforward: the fuse is inserted into compatible fuse holders or clips, ensuring a secure connection that prevents accidental dislodging during vibrations or thermal cycling. Regular inspection and replacement of fuses are essential to maintain system integrity, and the FLNR020’s clear ampere rating marking simplifies inventory management and troubleshooting. **Why Choose Littelfuse?** Littelfuse is a global leader in circuit protection, with over a century of innovation and expertise in electrical safety solutions. The company’s fuses, including the FLNR020, are trusted by industries worldwide for their **unmatched reliability, precision engineering, and adherence to international standards**. Littelfuse’s commitment to quality is evident in its rigorous testing protocols and continuous improvement in fuse technology. By choosing Littelfuse, industrial operators gain not only a high-performance product but also a partner dedicated to enhancing electrical safety and operational efficiency. For facilities where **safety, reliability, and uptime** are paramount, the Littelfuse FLNR020 Class RK5 20A cartridge fuse stands as a proven solution. Whether protecting critical infrastructure, industrial equipment, or sensitive electronics, this fuse delivers the performance and durability required to meet the demands of modern industrial environments.
  • 20A Class RK5 cartridge fuse for industrial overcurrent protection
  • High interrupting rating for safe fault current interruption
  • Cartridge-style design for easy installation and replacement
  • Compliant with UL and international industrial standards
  • Ideal for power distribution, machinery, and critical infrastructure

Specifications

Application
General Purpose
Brand Name
Littelfuse
Current Rating
20 A
Material
Cartridge-style construction
Series
RK5
Series
Class RK5
Series
FLNR
Special Features
Time-Delay
Standard
Standard 248-12 UL Listed/CSA
Sub Brand
POWR-GARD FLNR Series
Type
Class RK5
Package Weight (Imperial)
0.043 L
Package Weight (Metric)
19.600 g
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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.