Littelfuse FLSR020ID - FLSR020ID is a Class RK5 fuse with an ampere rating of 20 and cartridge-style construction.
Littelfuse

FLSR020ID

Alternate Item Number: FLSR020.TXID

UPC: 079458025385

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Minimum Qty: 10

Multiplier: 10

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Overview

The **Littelfuse FLSR020ID** is a high-performance **Class RK5 cartridge fuse** engineered for robust industrial circuit protection. With a **20-ampere rating**, this fuse is designed to safeguard critical electrical systems against overloads, short circuits, and ground faults, ensuring operational continuity and equipment safety. As part of Littelfuse’s industry-leading circuit protection portfolio, the FLSR020ID combines precision engineering with durable construction to deliver consistent performance in demanding environments. Class RK5 fuses are widely recognized for their **superior interrupting ratings** and **fast-acting response**, making them ideal for protecting sensitive industrial equipment such as motors, transformers, switchgear, and distribution panels. The **cartridge-style design** of the FLSR020ID ensures compatibility with standard RK5 fuse holders, simplifying installation and maintenance while minimizing downtime. Unlike generic fuses, RK5-class fuses meet stringent **UL 248 standards**, providing an added layer of reliability for professionals who prioritize safety and compliance. **Key Applications & Industries:** The FLSR020ID is a versatile solution for a broad range of industrial applications, including: - **Motor circuits** in manufacturing plants, where overload protection prevents costly damage to motors and associated equipment. - **Transformer protection** in substations and power distribution systems, where precise fault interruption is critical. - **Control panels and switchgear**, where RK5 fuses provide backup protection for branch circuits. - **Renewable energy systems**, including solar inverters and wind turbine controllers, where reliable fault isolation is essential. - **Data centers and critical infrastructure**, where uptime is non-negotiable and fuses must respond rapidly to faults. **Why Choose Littelfuse for Class RK5 Protection?** Littelfuse has been a trusted name in circuit protection for over a century, setting the benchmark for innovation and reliability in industrial safety. The **FLSR020ID** leverages Littelfuse’s proprietary **Time-Temperature-Tested® (TTT) design**, which ensures consistent performance across varying load conditions and ambient temperatures. This fuse is **UL Listed and CSA Certified**, meeting global safety standards and providing peace of mind for engineers and maintenance teams. **Installation & Maintenance Considerations:** Proper selection and installation of the FLSR020ID are straightforward due to its **standard cartridge dimensions** (1/4" x 1-1/4") and **color-coded end caps** for easy ampere identification. When replacing fuses, professionals should: - Verify the **ampere rating** matches the circuit requirements to avoid nuisance tripping or inadequate protection. - Inspect fuse holders for signs of wear or corrosion before installation to ensure a secure connection. - Follow **OSHA and NFPA 70E** guidelines for electrical safety, including proper PPE and lockout/tagout procedures. - Consider **coordination studies** when integrating the FLSR020ID into larger protection schemes to ensure selective tripping and minimize system-wide outages. **Performance & Reliability:** The FLSR020ID’s **high interrupting rating** (typically 200,000 amperes) ensures it can safely interrupt fault currents in high-fault systems, such as those found in industrial facilities. Its **low let-through energy (I²t)** helps reduce stress on downstream equipment during fault conditions, extending the lifespan of motors, cables, and other components. Additionally, the fuse’s **non-aging design** maintains consistent performance over time, reducing the need for frequent replacements. For industries where **downtime is costly**, the FLSR020ID delivers unmatched reliability. Whether deployed in harsh environments like chemical plants, mining operations, or food processing facilities, this fuse’s **robust construction** resists vibration, shock, and temperature extremes. Littelfuse’s global distribution network ensures quick availability, while their technical support team provides expert guidance on fuse selection, application-specific requirements, and compliance with local codes. **Conclusion:** The **Littelfuse FLSR020ID Class RK5 fuse** is more than just a protective component—it’s a critical safeguard for industrial electrical systems. By combining **superior fault interruption**, **durable construction**, and **Littelfuse’s legacy of innovation**, this fuse delivers the performance and reliability that professionals demand. Whether protecting motors, transformers, or control panels, the FLSR020ID ensures that your operations run smoothly, safely, and efficiently. Trust Littelfuse to keep your electrical systems secure, compliant, and optimized for peak performance.
  • 20A Class RK5 cartridge fuse for industrial circuit protection
  • High interrupting rating (200kA) for fault current interruption
  • UL 248 Listed and CSA Certified for global compliance
  • Fast-acting response to protect motors, transformers, and switchgear
  • Durable construction for harsh industrial environments

Specifications

Application
General Purpose
Brand Name
Littelfuse
Current Rating
20 A
Material
Cartridge-style construction
Mounting Type
Cartridge fuse holder
Series
Class RK5
Size
Cartridge-style
Size
1/4" x 1-1/4"
Special Features
Time-Delay
Standard
Standard 248-12 UL Listed/CSA
Sub Brand
POWR-GARD FLSR Series
Type
Class RK5
Package Weight (Imperial)
0.180 L
Package Weight (Metric)
0.082 kg
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Fuse Holder Modulostar® Size 10x38 IEC 690VAC 690VDC 3-Pole IP20

E1062696

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

9F61BWW460

9F61 Size B Clips 1.6in

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.