Littelfuse LA50QS90-4 - LA50 VERY FAST-ACTI SEMICOND FUSE QS90-4. In response to new equipment requirements, Littelfuse LA50QS series fuses were developed to improve the overall performance of semiconductor fuses. The LA50QS provides the best protection features including lower I2t, longer life when subjected to cyclic loading and lower watts loss. LA50QS is today’s choice for the protection of dynamic solid state equipment. Features: Lowest I2t for greatest protection of semiconductor circuits. Low watts loss for cooler operation. Superior cycling ability gives an equipment design advantage. State-of-the-art protection for 500 volt equipment. Ultra compact sizes allow down-sizing of existing equipment. Applications: Protection of 500 volts or less solid state equipment such as motor drives, UPS, inverters, etc.
Littelfuse

LA50QS90-4

Alternate Item Number: LA50QS904

UPC: 079458152173

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Overview

The Littelfuse LA50QS90-4 represents a significant advancement in semiconductor fuse technology, engineered to deliver unparalleled protection for modern, high-performance solid-state equipment operating at up to 500 volts. As the demands on electronic systems continue to escalate, the need for robust and reliable protection components becomes paramount. The LA50QS series, including the LA50QS90-4, was specifically developed by Littelfuse to address these evolving requirements, offering superior performance characteristics that go beyond conventional fuse capabilities. At the core of the LA50QS90-4's exceptional protection is its remarkably low I²t rating. This critical parameter quantifies the total energy a fuse can withstand before interrupting a circuit, and a lower I²t value signifies faster and more effective clearing of fault currents. For sensitive semiconductor devices, such as those found in power electronics, minimizing the energy let-through during a fault is crucial to prevent catastrophic damage. The LA50QS90-4 excels in this regard, providing the highest level of protection for your valuable semiconductor components, thereby enhancing equipment longevity and reducing costly downtime. Beyond its superior fault current interruption capabilities, the LA50QS90-4 also boasts significantly reduced watts loss. This translates directly into cooler operation for the fuse itself and the surrounding equipment. Lower operating temperatures contribute to increased reliability, extended component lifespan, and can even allow for more compact equipment designs by reducing the need for extensive thermal management solutions. This efficiency is a key differentiator for engineers seeking to optimize their system's overall performance and energy consumption. Furthermore, the LA50QS90-4 exhibits superior cycling ability when subjected to cyclic loading. Many industrial applications involve frequent power cycles or fluctuating load conditions. Fuses that can withstand these repetitive stresses without degradation are essential for long-term operational integrity. The advanced construction and materials used in the LA50QS90-4 ensure it maintains its protective characteristics over extended periods of cyclic operation, providing a reliable design advantage for engineers. This fuse is an ideal choice for a wide array of applications where robust semiconductor protection is critical. Key applications include: * Motor Drives: Protecting variable frequency drives (VFDs) and other motor control systems. * Uninterruptible Power Supplies (UPS): Safeguarding critical power backup systems. * Inverters: Ensuring the reliable operation of DC-AC power conversion systems. * Power Supplies: Protecting sensitive power conversion circuits. * Other 500V Solid-State Equipment: Any application requiring high-speed, low-energy-let-through protection for semiconductor devices. The ultra-compact size of the LA50QS90-4 also offers a significant advantage, enabling engineers to downsize existing equipment or achieve more densely packed designs. This space-saving capability is increasingly important in today's competitive manufacturing landscape. When selecting semiconductor fuses, engineers prioritize reliability, performance, and adherence to safety standards. Littelfuse, a globally recognized leader in circuit protection, has a long-standing reputation for delivering high-quality, innovative solutions. The LA50QS90-4 is a testament to this commitment, offering state-of-the-art protection that meets the stringent demands of modern industrial and commercial applications. Trust the Littelfuse LA50QS90-4 to safeguard your critical semiconductor equipment and ensure optimal operational performance.
  • Lowest I²t rating for maximum semiconductor circuit protection.
  • Low watts loss ensures cooler operation and extended equipment life.
  • Superior cycling ability for reliable performance under cyclic loading.
  • State-of-the-art protection for 500 volt solid-state equipment.
  • Ultra-compact size allows for equipment down-sizing and design flexibility.

Specifications

Application
Protection of Semiconductors
Brand Name
Littelfuse
Series
LA50QS
Size
Ultra compact
Special Features
Very-Fast Acting
Standard
UL Recognized
Sub Brand
LA Series
Type
Semiconductor Fuse
Voltage Rating
500 V V
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.