Littelfuse FLSR090 - FLSR090 is a Class RK5 fuse with an ampere rating of 90 and knife-blade-style construction.
Littelfuse

FLSR090

Alternate Item Number: FLSR090.V

UPC: 079458170818


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Overview

The **Littelfuse FLSR090** is a premium **Class RK5 fuse** engineered for high-performance industrial applications requiring precise overcurrent protection. With a **90A ampere rating** and **knife-blade-style construction**, this fuse delivers robust performance in demanding electrical systems where reliability and safety are critical. Designed to meet stringent industry standards, the FLSR090 ensures optimal protection against short circuits, overloads, and fault conditions, making it an essential component in modern power distribution and control systems. Class RK5 fuses like the FLSR090 are widely recognized for their **high interrupting rating**, **fast response times**, and **superior thermal stability**, which are essential for safeguarding sensitive industrial equipment. The **knife-blade design** ensures secure, low-resistance connections in fuse blocks and panels, reducing the risk of arcing or loose contacts that could compromise system integrity. Littelfuse, a global leader in circuit protection solutions, has designed this fuse to withstand harsh operating environments, including extreme temperatures, vibration, and electrical stress, ensuring long-term durability and consistent performance. **Key Applications & Industries** The **FLSR090** is ideal for a broad range of industrial applications, including: - **Power distribution panels** in manufacturing plants, refineries, and chemical processing facilities. - **Motor control centers (MCCs)** where reliable overload and short-circuit protection is critical for motors and associated equipment. - **Switchgear and switchboards** in commercial buildings, data centers, and utility substations. - **Renewable energy systems**, such as solar and wind power installations, where precise fault protection is required. - **Heavy machinery and industrial equipment**, including conveyors, pumps, and compressors, to prevent catastrophic failures. **Why Choose Littelfuse for Class RK5 Fuses?** Littelfuse has been a trusted name in circuit protection for over a century, with a reputation for innovation, quality, and reliability. The **FLSR090** is manufactured in compliance with **UL 248** and **IEC 60269** standards, ensuring it meets the rigorous safety and performance requirements of global industrial markets. Professionals in electrical engineering, maintenance, and safety rely on Littelfuse fuses for their **consistent response characteristics**, **high interrupting ratings (up to 200kA)**, and **extended service life**, which reduce downtime and maintenance costs. **Installation & Compatibility Considerations** When selecting the **FLSR090**, ensure compatibility with **Class RK5 fuse blocks** or holders designed for knife-blade fuses. Proper installation is critical to achieving optimal performance—always verify the fuse’s ampere rating matches the system’s requirements and that the fuse block is rated for the same voltage and interrupting capacity. For applications with high inrush currents or frequent cycling, consider using **time-delay versions** of Class RK5 fuses to prevent nuisance tripping while maintaining protection. **Industry Trends & Future-Proofing** As industrial systems evolve with advancements in **smart manufacturing, IoT integration, and energy efficiency**, the demand for high-performance circuit protection solutions like the **FLSR090** continues to grow. Littelfuse stays ahead of industry trends by offering fuses that support **arc flash mitigation**, **selective coordination**, and **energy management**, helping facilities comply with **NFPA 70E** and **OSHA** safety regulations. By investing in a **Littelfuse Class RK5 fuse**, industrial professionals ensure their electrical systems are protected against both immediate faults and long-term reliability risks. For engineers, electricians, and facility managers seeking a **trusted, high-quality fuse** for critical applications, the **Littelfuse FLSR090** delivers unmatched performance, durability, and peace of mind. Whether deployed in a **petrochemical plant, automotive manufacturing facility, or data center**, this fuse provides the reliability needed to keep operations running smoothly and safely.
  • 90A ampere rating for Class RK5 applications
  • Knife-blade construction for secure, low-resistance connections
  • High interrupting rating (up to 200kA) for superior fault protection
  • Compliant with UL 248 and IEC 60269 safety standards
  • Ideal for power distribution, motor control, and switchgear systems

Specifications

Application
General Purpose
Brand Name
Littelfuse
Connection Type
Knife-blade
Current Rating
90 A
Nema Rating
Class RK5
Series
Class RK5
Series
FLSR
Size
Knife-blade-style
Special Features
Time-Delay
Standard
Standard 248-12 UL Listed/CSA
Sub Brand
POWR-GARD FLSR Series
Type
Class RK5
Package Weight (Imperial)
0.577 L
Package Weight (Metric)
262.400 g
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

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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.