Littelfuse LA15QS40-4TI - The Littelfuse LA15QS series semiconductor fuses were designed for the specific protection of diodes and other semiconductor devices rated 150VAC/DC. The LA15QS product lines compact design is perfect for those applications that have limitations on available space.
Littelfuse

LA15QS40-4TI

Alternate Item Number: LA15QS404TI

UPC: 079458155839

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Overview

The Littelfuse LA15QS40-4TI semiconductor fuse is a high-performance protection solution engineered for diodes and sensitive semiconductor devices operating at 150VAC/DC. Designed for industrial and electronic systems where space is at a premium, this compact fuse combines reliability with precise fault interruption to safeguard critical components from overcurrent conditions. Trusted by engineers and technicians worldwide, the LA15QS series from Littelfuse delivers consistent performance in applications ranging from power supplies and motor drives to renewable energy inverters and industrial automation systems. Its robust construction ensures long-term durability, while the optimized design minimizes voltage drop and thermal stress, enhancing overall system efficiency. Semiconductor protection is a critical consideration in modern electrical and electronic systems, where even brief overcurrent events can lead to catastrophic failures, reduced lifespan, or costly downtime. The Littelfuse LA15QS40-4TI addresses these challenges with a fast-acting fuse element that responds to fault conditions in milliseconds, isolating faulty components before damage spreads. This level of protection is particularly vital in high-reliability applications such as: - **Power conversion systems**, including solar inverters, UPS units, and battery management systems, where consistent voltage regulation is essential. - **Industrial motor drives and controllers**, where semiconductor devices like IGBTs and MOSFETs are susceptible to transient overcurrents during startup or fault conditions. - **Automotive and transportation electronics**, including EV charging systems and traction inverters, where compact form factors and high reliability are non-negotiable. - **Telecommunications and data center infrastructure**, where uninterrupted operation is critical to maintaining network integrity. The compact design of the LA15QS40-4TI makes it an ideal choice for space-constrained installations, allowing engineers to optimize panel layouts without sacrificing protection. Unlike traditional fuses, semiconductor-specific fuses like the LA15QS series are engineered with lower let-through energy (I²t) values, ensuring faster response times and reduced stress on protected components. This is particularly important in applications involving sensitive semiconductors, where even minor overcurrent events can degrade performance or lead to premature failure. Littelfuse, a global leader in circuit protection solutions, has built a reputation for innovation and reliability in the industrial and electronics markets. With decades of experience in developing advanced fuse technologies, the company’s semiconductor fuses are trusted by professionals across industries for their precision, consistency, and adherence to international safety standards. The LA15QS series, including the LA15QS40-4TI, is no exception—it meets rigorous UL, IEC, and other global certifications, ensuring compliance with the most demanding regulatory requirements. When selecting a semiconductor fuse, professionals prioritize factors such as voltage rating, interrupting rating, response time, and physical dimensions. The LA15QS40-4TI excels in all these areas, offering a 150VAC/DC rating to accommodate a wide range of applications, from low-voltage control circuits to high-power industrial systems. Its compact form factor (40mm length, 6.3mm diameter) allows for easy integration into tight spaces, while the fast-acting design ensures minimal downtime during fault events. Installation is straightforward, with standard fuse holder compatibility and clear labeling for quick identification. For engineers and technicians tasked with designing or maintaining systems where semiconductor protection is paramount, the Littelfuse LA15QS40-4TI semiconductor fuse provides a dependable, space-saving solution. Whether deployed in a rugged industrial environment or a precision electronics application, this fuse delivers the reliability and performance professionals demand. Backed by Littelfuse’s global support network and extensive technical resources, the LA15QS40-4TI is a smart investment in system longevity and operational safety.
  • 150VAC/DC rated for versatile industrial and electronic applications
  • Compact 40mm design ideal for space-constrained installations
  • Fast-acting protection for diodes and semiconductor devices
  • UL/IEC certified for global compliance and safety
  • Trusted Littelfuse quality with decades of circuit protection expertise

Specifications

Application
Protection of Semiconductors
Brand Name
Littelfuse
Series
LA15QS
Size
40mm length, 6.3mm diameter
Special Features
Very-Fast Acting
Standard
UL Recognized
Sub Brand
LA Series
Type
Semiconductor Fuse
Voltage Rating
150VAC/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 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.