Littelfuse KLNR010 - KLNR/KLSR series RK1 fast-acting fuses were the earliest type of current-limiting fuse developed. Their single-element, silver link design enables them to provide fast-acting overload and short-circuit protection. When used to protect inductive loads such as motors, solenoids, and transformers, KLNR/KLSR series fuses must be greatly oversized to prevent opening the fuses on harmless inrush currents. In such applications, KLNR/KLSR series fuses may only provide short-circuit protection. We recommend using POWR-PRO™ LLNRK/LLSRK series RK1, dual-element, time-delay fuses in all new applications requiring the current-limiting ability of UL Class RK1 fast-acting fuses, or in existing applications where fast-acting RK1 or RK5 fuses have been opening on harmless system surges such as motor starting currents.
Littelfuse

KLNR010

Alternate Item Number: KLNR010.T

UPC: 079458280654

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Overview

The Littelfuse KLNR010, part of the KLNR/KLSR series, represents an early and foundational design in current-limiting fuse technology. As an RK1 class fast-acting fuse, its single-element, silver link construction is engineered for rapid response to both overloads and short circuits. This inherent speed makes it a critical component for safeguarding sensitive industrial equipment and electrical systems from damaging current surges. Historically, these fuses were among the first to offer robust current-limiting capabilities, a vital feature in preventing cascading failures within complex electrical networks. The KLNR010's design prioritizes swift interruption of fault currents, thereby minimizing arc flash hazards and protecting downstream components from irreparable damage. Its reliability in these critical protection scenarios has cemented its place in industrial applications where uptime and equipment longevity are paramount. However, it is crucial to understand the operational characteristics of single-element, fast-acting fuses when applied to inductive loads. Applications involving motors, solenoids, and transformers inherently generate significant inrush currents during startup. To prevent the KLNR010 from unnecessarily interrupting the circuit during these harmless transient events, it often requires substantial oversizing. In such scenarios, the primary protective function may be limited to short-circuit events, with overload protection being less effective due to the necessary oversizing. For new installations or existing systems experiencing nuisance tripping from harmless surges like motor starting currents, Littelfuse strongly recommends the advanced POWR-PRO™ LLNRK/LLSRK series. These dual-element, time-delay fuses offer a superior solution by accommodating inrush currents while still providing excellent overload and short-circuit protection. This dual-element design ensures that the fuse can reliably protect against both sustained overloads and sudden short circuits without compromising operational continuity during normal startup sequences. Despite the recommendation for newer technologies in specific applications, the KLNR010 remains a viable and effective solution for many industrial environments where its fast-acting characteristics are precisely what is needed. Its straightforward design and proven performance make it a dependable choice for applications that do not involve significant inductive inrush. When selecting the appropriate fuse, engineers and maintenance professionals must carefully consider the load characteristics to ensure optimal protection and system stability. The Littelfuse KLNR010 is a testament to the enduring value of well-engineered protective devices in maintaining the integrity of industrial power systems. Key features and considerations for the Littelfuse KLNR010: * **Fast-Acting Protection:** Designed for rapid interruption of overloads and short circuits. * **Single-Element Silver Link:** Provides quick response and reliable fault interruption. * **Current-Limiting Capability:** Minimizes damage from high fault currents. * **Application Considerations:** Requires oversizing for inductive loads (motors, solenoids, transformers) to avoid nuisance tripping on inrush currents. * **Recommended Alternative:** For inductive loads or systems with surges, consider Littelfuse POWR-PRO™ LLNRK/LLSRK dual-element, time-delay fuses. * **Industrial Reliability:** A foundational component for safeguarding electrical infrastructure.
  • Littelfuse KLNR010 RK1 fast-acting fuse for industrial electrical protection.
  • Single-element, silver link design for rapid overload and short-circuit interruption.
  • Provides essential current-limiting capabilities to protect sensitive equipment.
  • Note: May require oversizing for inductive loads (motors, solenoids, transformers) due to inrush currents.
  • Consider POWR-PRO™ LLNRK/LLSRK series dual-element, time-delay fuses for applications with significant inrush.

Specifications

Amperage Rating
4 Amp
Application
DC control circuits/Solar
Brand Name
Littelfuse
Material
Silver link
Series
KLNR/KLSR
Special Features
Fast-Acting
Standard
UL 2579 IEC 60269-6
Sub Brand
POWR-GARD KLKD Series
Type
UL Supplemental
Fuse Block 600VAC 600VDC Class CC 30A 1/4in Quick Connect / Solder 90 angle screw Knob Panel Mount

GPM-SRR90

Fuse Block 600VAC 600VDC Class CC 30A 1/4in Quick Connect / Solder 90 angle screw Knob Panel Mount
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
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.