Littelfuse JLLN400.XXP - JLLN400P is a Class T fuse with an ampere rating of 400 and knife-blade-style construction.
Littelfuse

JLLN400.XXP

Alternate Item Number: JLLN400.XXP

UPC: 079458821505


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Overview

The **Littelfuse JLLN400.XXP Class T fuse** is a high-performance overcurrent protection solution engineered for the most demanding industrial applications. With a **400A current rating** and **knife-blade-style construction**, this fuse delivers unmatched reliability in power distribution, motor control, and automation systems where consistent performance is critical. Designed to meet the rigorous demands of modern electrical infrastructure, the JLLN400.XXP ensures rapid response to fault conditions while maintaining operational continuity in harsh environments. Class T fuses are widely recognized for their superior performance in high-inrush applications, such as those found in industrial machinery, variable frequency drives (VFDs), and heavy-duty motor circuits. The **knife-blade-style connection** provides a secure, low-resistance interface that minimizes installation time and reduces the risk of loose connections—a common source of electrical failures. This design also simplifies replacement, helping maintenance teams reduce downtime and operational costs. Littelfuse, a global leader in circuit protection, has built a reputation for engineering fuses that combine durability with precision. The **JLLN400.XXP** is no exception, offering a robust solution for facilities where uptime is non-negotiable. Its **Class T classification** ensures compliance with stringent safety standards, including UL 248-14, making it suitable for use in power distribution panels, branch circuits, and industrial control systems. Key advantages of the JLLN400.XXP include: - **High interrupting rating** for protection against severe fault currents, preventing catastrophic damage to equipment. - **Fast-acting response** to overcurrent events, reducing the risk of thermal stress and equipment failure. - **Compact and space-efficient design**, ideal for tight panel configurations in industrial settings. - **Wide application compatibility**, from motor starters to transformers and branch circuit protection. - **Trusted manufacturer reliability**, backed by Littelfuse’s decades of expertise in circuit protection solutions. Professionals in industries such as manufacturing, mining, oil & gas, and renewable energy rely on Class T fuses like the JLLN400.XXP to safeguard critical assets. When selecting a fuse for high-availability systems, factors such as **interrupting rating, response time, and connection type** are paramount. The knife-blade-style construction of this fuse ensures a stable, high-conductivity interface, while its **400A rating** makes it suitable for medium to high-power applications. Littelfuse’s commitment to innovation and quality ensures that the JLLN400.XXP meets the evolving needs of industrial electrical systems. Whether protecting a motor control center, a power distribution unit, or an automation panel, this fuse provides the performance and dependability required in today’s fast-paced industrial landscape. For facilities where electrical reliability is a top priority, the **Littelfuse JLLN400.XXP Class T fuse** is a proven choice for long-term protection and operational efficiency.
  • 400A Class T fuse for high-performance industrial applications
  • Knife-blade-style construction for secure, low-resistance connections
  • Superior interrupting rating for protection against severe fault currents
  • Fast-acting response to minimize equipment damage and downtime
  • Trusted Littelfuse quality for demanding electrical environments

Specifications

Amperage Rating
400 Amp
Application
Variable Speed Drives
Brand Name
Littelfuse
Interrupt Rating
50000A@160VDC
Response Time
Fast-Acting (F)
Sub Brand
POWR-GARD JLLN Series
Type
Class T
Voltage Rating
300/160 VAC/VDC
Fuse Block 600VAC 600VDC Class CC 30A 1/4in Quick Connect / Solder 90 angle screw Knob Panel Mount

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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
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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.