Littelfuse LA100P400-4 - Littelfuse's LA100P semiconductor protection fuses are rated 1000V, extending the range of protection for UPS systems, AC and DC drives, reduced voltage motor starters and similar applications where lower l2t and superior reliability are needed. With ratings from 15-1000 amperes, a wide range of high voltage applications can be served. Features: Low l2t minimizes damage to protected components on short circuit. Controlled arc voltage reduces stress to circuit components during fuse clearing. Applications: Protection of UPS systems, AC/DC drives, reduced voltage motor starters and other 1000V or less semiconductor devices.
Littelfuse

LA100P400-4

Alternate Item Number: LA100P4004

UPC: 079458151787

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Overview

Littelfuse LA100P400-4 semiconductor protection fuses are engineered to deliver unmatched reliability and performance in high-voltage industrial applications up to 1000V. Designed for mission-critical systems where semiconductor protection is non-negotiable, these fuses provide robust defense against short circuits while minimizing collateral damage to sensitive downstream components. With a current rating of 400 amperes, the LA100P400-4 is part of Littelfuse’s premium LA100P series, which extends protection across a broad spectrum of high-power applications including UPS systems, AC/DC drives, reduced voltage motor starters, and other semiconductor-based equipment operating at or below 1000V. The core advantage of the LA100P400-4 lies in its low I²t (let-through energy) characteristic, which ensures rapid response to fault conditions while limiting the energy let through during a short circuit event. This is critical in protecting delicate semiconductor devices such as IGBTs, thyristors, and MOSFETs, where even microsecond delays or excessive energy can lead to catastrophic failure. The fuse’s controlled arc voltage during clearing further reduces stress on circuit components, preventing voltage spikes that could damage capacitors, transistors, or other sensitive elements. These features make the LA100P400-4 ideal for applications where operational continuity and equipment longevity are paramount. Industries that rely on high-voltage semiconductor protection—such as renewable energy (solar inverters, wind power converters), industrial automation, electric vehicle charging infrastructure, and heavy machinery—demand fuses that combine precision engineering with proven reliability. The LA100P400-4 meets these requirements with a robust design that supports installation in both AC and DC circuits, making it a versatile choice for engineers designing protection schemes for variable frequency drives (VFDs), motor controllers, and power conversion systems. Its 1000V rating ensures compatibility with modern high-voltage architectures, while the 400A current rating provides ample headroom for high-power applications without compromising response time or safety margins. Selecting the right semiconductor protection fuse involves evaluating several key parameters beyond just voltage and current ratings. Professionals must consider the fuse’s I²t value to ensure it aligns with the let-through energy tolerance of the protected semiconductor devices. The LA100P400-4 excels in this regard, offering a low I²t that enhances protection while maintaining fast clearing times. Additionally, the controlled arc voltage feature reduces the risk of secondary faults, such as insulation breakdown or component stress, which can occur during high-energy interruptions. Installation is straightforward, with Littelfuse providing comprehensive technical documentation and support to ensure proper integration into existing protection schemes. Littelfuse, a global leader in circuit protection solutions, has built a reputation for innovation and reliability in the industrial and power electronics markets. With over a century of experience, the company’s semiconductor protection fuses are trusted by engineers worldwide to safeguard critical infrastructure. The LA100P series, including the LA100P400-4, reflects Littelfuse’s commitment to advancing protection technologies that enhance system uptime, reduce maintenance costs, and improve operational efficiency. For applications where failure is not an option, the LA100P400-4 delivers the performance and peace of mind that only a trusted manufacturer can provide.
  • 1000V rating for high-voltage industrial applications
  • Low I²t minimizes damage to protected semiconductor components
  • Controlled arc voltage reduces stress on circuit components during clearing
  • 400A current rating for high-power applications
  • Compatible with UPS systems, AC/DC drives, and motor starters

Specifications

Application
Protection of Semiconductors
Brand Name
Littelfuse
Current Rating
400 A
Current Rating
15-1000A
Series
LA100P
Special Features
Very-Fast Acting
Standard
UL Recognized
Sub Brand
LA Series
Type
Semiconductor Fuse
Voltage Rating
1000 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 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.