Littelfuse KLSR015 - KLSR series RK1 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, KLSR series fuses must be greatly oversized to prevent opening the fuses on harmless inrush currents. In such applications, 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 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

KLSR015

Alternate Item Number: KLSR015.T

UPC: 079458290684

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Overview

The Littelfuse KLSR015, part of the pioneering KLSR series, represents an early yet effective advancement in current-limiting fuse technology. Engineered with a single-element, silver link design, this RK1 class fuse delivers rapid response to both overload conditions and dangerous short circuits. Its primary function is to safeguard electrical systems and equipment from damage caused by excessive current, ensuring operational continuity and safety in demanding industrial environments. While the KLSR015 excels in providing fast-acting protection, it's crucial to understand its application nuances, particularly when protecting inductive loads. For equipment such as motors, solenoids, and transformers, which characteristically experience significant inrush currents upon startup, the KLSR015 may necessitate substantial oversizing. This oversizing is a practical measure to prevent the fuse from unnecessarily opening due to these harmless, transient surges. In such specific scenarios, the KLSR015 might primarily serve as a robust short-circuit protection device, offering a critical layer of defense against catastrophic failures. For applications demanding the advanced current-limiting capabilities of UL Class RK1 fuses, especially in new installations or in existing systems where older RK1 or RK5 fast-acting fuses are prone to nuisance tripping from system surges like motor starting currents, Littelfuse strongly recommends their POWR-PRO™ LLNRK/LLSRK series. These dual-element, time-delay fuses are engineered to provide superior protection by accommodating normal inrush currents while still offering excellent overload and short-circuit protection. This makes them the preferred choice for modern industrial applications requiring a more sophisticated and reliable protective solution. Despite the availability of newer technologies, the KLSR015 remains a trusted component for specific applications where its fast-acting characteristics are paramount and its limitations with inductive loads are well-managed. Its legacy is built on providing dependable protection for power distribution systems and critical industrial machinery. When selecting fuses, understanding the load characteristics and consulting manufacturer recommendations, like those for the POWR-PRO™ series, is essential for optimal system performance and safety. The KLSR015 is a testament to Littelfuse's long-standing commitment to electrical safety and innovation. Key Features: * **Fast-Acting Protection:** Designed for rapid response to overloads and short circuits. * **UL Class RK1:** Meets stringent current-limiting fuse standards. * **Single-Element Design:** Utilizes a silver link for efficient operation. * **Industrial Application:** Suitable for power distribution and equipment protection. * **Legacy Technology:** An established solution for specific protection needs.
  • Littelfuse KLSR015 RK1 current-limiting fuse for industrial applications.
  • Single-element, silver link design for fast-acting overload and short-circuit protection.
  • UL Class RK1 compliant, ensuring robust protection for electrical systems.
  • May require oversizing for inductive loads (motors, solenoids, transformers) due to inrush currents.
  • Recommended for new applications or systems with surges: Littelfuse POWR-PRO™ LLNRK/LLSRK series.

Specifications

Amperage Rating
5 AMP
Application
low amp - space saving
Brand Name
Littelfuse
Material
Silver
Series
KLSR
Special Features
Fast-Acting
Standard
Supplemental Protection
Sub Brand
POWR-GARD BLS Series
Type
UL Supplemental
Package Weight (Imperial)
0.182 L
Package Weight (Metric)
82.600 g
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.