Littelfuse LLSRK17.5 - RK1 fuses are extremely current-limiting fuses meaning they greatly reduce or eliminate damage to circuits and equipment under short-circuit conditions. Replacing existing Class H, K and RK5 fuses with RK1 fuses is one of the easiest ways to immediately improve the protection of plant workers and equipment.
Littelfuse

LLSRK17.5

Alternate Item Number: LSRK17.5T

UPC: 079458350692

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Overview

The Littelfuse RK1 fuses, identified by SKU LLSRK17.5, represent a significant advancement in industrial circuit protection. Engineered with exceptional current-limiting capabilities, these fuses are designed to drastically reduce or entirely eliminate damage to sensitive circuits and valuable equipment during sudden and severe short-circuit events. This superior performance makes them an ideal and immediate upgrade for facilities currently utilizing older fuse technologies such as Class H, Class K, and RK5 fuses. By transitioning to Littelfuse RK1 fuses, industrial operations can achieve an immediate and tangible improvement in the safety of their plant personnel and the integrity of their equipment. The advanced design of RK1 fuses ensures a rapid response to fault conditions, minimizing the duration of dangerous electrical arcs and thereby mitigating potential hazards. This rapid fault interruption is crucial in high-demand industrial environments where equipment downtime can lead to substantial financial losses and operational disruptions. These fuses are not merely a replacement part; they are a strategic investment in operational reliability and safety. Their enhanced protection characteristics contribute directly to increased uptime and reduced maintenance costs associated with equipment damage. The Littelfuse brand is synonymous with quality and dependability in the electrical protection industry, and the LLSRK17.5 RK1 fuse is a testament to this reputation. Professionals in electrical engineering and maintenance trust Littelfuse for robust solutions that meet stringent industry standards. Key benefits and features of the Littelfuse RK1 fuses include: * **Superior Current-Limiting:** Significantly reduces peak let-through current and I²t, minimizing damage to downstream components. * **Enhanced Safety:** Provides a higher level of protection for personnel and equipment against short-circuit faults. * **Direct Upgrade Path:** Easily replaces existing Class H, K, and RK5 fuses, offering immediate performance improvements without extensive system modifications. * **Reliable Performance:** Engineered for consistent and dependable operation in demanding industrial applications. * **Reduced Downtime:** Minimizes the impact of short circuits, leading to less unplanned downtime and associated costs. Typical applications for the Littelfuse RK1 fuses (LLSRK17.5) span a wide range of industrial sectors. They are commonly found protecting: * Industrial machinery and automation equipment * Power distribution panels and switchgear * Motor control centers * Variable frequency drives (VFDs) and soft starters * Transformers and other critical power components When selecting fuses for industrial applications, factors such as voltage rating, current rating, interrupting rating, and fuse class are paramount. The RK1 class, as exemplified by the LLSRK17.5, offers a distinct advantage in terms of current-limiting performance compared to older fuse classes. This makes them particularly suitable for applications where the protection of sensitive electronics or the prevention of cascading failures is critical. The installation of these fuses should always be performed by qualified personnel in accordance with local electrical codes and manufacturer guidelines to ensure optimal performance and safety. The Littelfuse LLSRK17.5 RK1 fuse is a critical component for any industrial facility looking to bolster its electrical protection strategy and ensure the longevity and safety of its operational infrastructure.
  • Exceptional current-limiting performance to minimize circuit and equipment damage during short circuits.
  • Direct upgrade for Class H, K, and RK5 fuses, enhancing protection immediately.
  • Significantly improves safety for plant workers and equipment.
  • Engineered for rapid response to fault conditions, reducing downtime.
  • Trusted Littelfuse quality for reliable industrial electrical protection.

Specifications

Amperage Rating
17.5 Amp
Application
All general purpose circuits
Brand Name
Littelfuse
Series
RK1
Special Features
Time-Delay
Standard
Standard 248-12 UL Listed/CSA
Sub Brand
LLSRK Series
Type
Class RK1
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 Modulostar® Size 10x38 IEC 690VAC 690VDC 3-Pole IP20

E1062696

Fuse Holder Modulostar® Size 10x38 IEC 690VAC 690VDC 3-Pole IP20
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
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.