Littelfuse LA70QS500-4K - VERY FAST-ACTI SEMICOND FUSE QS500-4K. Littelfuse LA70QS semiconductor fuses were developed to provide improved performance required by today’s new equipment. The LA70QS features lower I2t, improved cycling, and lower watts loss. It is the best choice for the protection of dynamic solid-state equipment. Features: Very low I2t improved protection of equipment. Superior cycling ability for long, reliable life on high cycling loading. Lower watts loss for cooler operation. 700 Volt AC/DC rating provides greater design versatility. Compact sizes allow downsizing of equipment. Applications: Protection of 700 volt or less solid state equipment such as motor drives, UPS, inverters, etc.
Littelfuse

LA70QS500-4K

Alternate Item Number: LA70QS5004K

UPC: 079458153057

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Overview

The Littelfuse LA70QS500-4K is a premium Very Fast-Acting Semiconductor Fuse engineered to deliver exceptional protection for dynamic solid-state equipment. Manufactured by Littelfuse, a globally recognized leader in circuit protection, this fuse (SKU: LA70QS500-4K) is specifically designed to meet the rigorous demands of modern industrial applications where reliability and performance are paramount. Its advanced design offers significant improvements over conventional fuses, making it the ideal choice for safeguarding sensitive electronic components. At the core of the LA70QS500-4K's superior performance is its exceptionally low I²t rating. This critical specification quantifies the fuse's ability to withstand surge currents and fault conditions, providing a faster and more precise response to overcurrent events. A lower I²t value means the fuse will interrupt a fault current more quickly, thereby minimizing the duration and magnitude of damaging energy that can impact protected equipment. This enhanced protection is crucial for extending the lifespan and ensuring the operational integrity of sophisticated solid-state devices. Furthermore, the LA70QS500-4K excels in applications characterized by frequent power cycling. Its superior cycling ability ensures long, reliable operational life even under demanding high-cycling loading conditions. This resilience is vital in systems like motor drives and uninterruptible power supplies (UPS) that experience frequent start-stop cycles or power fluctuations. By resisting fatigue from repeated stress, this fuse reduces the likelihood of premature failure and the associated downtime and maintenance costs. Another key benefit of the LA70QS500-4K is its reduced watts loss. This characteristic translates to cooler operation of the fuse itself and the surrounding equipment. Lower heat generation not only contributes to a more stable operating environment but also allows for potential downsizing of equipment by reducing the need for extensive thermal management solutions. This efficiency can lead to significant cost savings in terms of energy consumption and enclosure design. The 700 Volt AC/DC rating of the LA70QS500-4K provides exceptional design versatility. This broad voltage capability makes it suitable for a wide array of applications across different voltage classes, simplifying component selection and inventory management for engineers and system designers. Whether the application requires AC or DC protection, this fuse offers a robust and reliable solution. Key Features and Benefits: * **Very Low I²t:** Delivers superior protection for sensitive solid-state equipment by interrupting faults rapidly. * **Superior Cycling Ability:** Ensures long, reliable operational life in high-cycling applications, minimizing downtime. * **Lower Watts Loss:** Promotes cooler operation, enhancing equipment stability and potentially enabling equipment downsizing. * **700 Volt AC/DC Rating:** Offers broad design versatility for diverse applications. * **Compact Sizes:** Facilitates equipment miniaturization and space savings. Applications for the Littelfuse LA70QS500-4K are extensive and include the protection of 700 volt or less solid-state equipment. This encompasses critical components such as motor drives, uninterruptible power supplies (UPS), inverters, rectifiers, and other power electronic systems where fast-acting, reliable overcurrent protection is essential. For engineers and manufacturers seeking to enhance the performance, reliability, and longevity of their solid-state equipment, the Littelfuse LA70QS500-4K semiconductor fuse stands out as a technically advanced and cost-effective solution.
  • Very low I²t for improved protection of sensitive solid-state equipment.
  • Superior cycling ability ensures long, reliable life in high-cycling applications.
  • Lower watts loss for cooler operation and enhanced equipment stability.
  • 700 Volt AC/DC rating provides greater design versatility.
  • Compact sizes allow for downsizing of equipment.

Specifications

Application
Protection of Semiconductors
Brand Name
Littelfuse
Series
LA70QS
Size
Compact
Special Features
Very-Fast Acting
Standard
UL Recognized
Sub Brand
LA Series
Type
Semiconductor Fuse
Voltage Rating
700 V AC/DC
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.