Littelfuse LA70QS350-4 - LA70 VERY FAST-ACT SEMICOND FUSE QS350-4. 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

LA70QS350-4

Alternate Item Number: LA70QS3504

UPC: 079458152777

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Overview

The Littelfuse LA70QS350-4 is a cutting-edge very fast-acting semiconductor fuse engineered to provide superior protection for dynamic solid-state equipment operating at up to 700 Volts AC/DC. Designed to meet the stringent performance demands of modern industrial applications, this fuse from Littelfuse offers a significant upgrade in protection capabilities compared to conventional fuses. At the core of the LA70QS350-4's performance is its exceptionally low I²t rating. This critical parameter quantifies the total energy a fuse can withstand before blowing, and a lower I²t directly translates to faster and more precise interruption of fault currents. This enhanced protection is vital for safeguarding sensitive semiconductor components within motor drives, uninterruptible power supplies (UPS), inverters, and other power electronic systems, preventing catastrophic damage and costly downtime. The improved protection ensures the longevity and reliability of your valuable equipment. Furthermore, the LA70QS series, including the LA70QS350-4, boasts superior cycling ability. This feature is paramount in applications that experience frequent power fluctuations or load changes. The fuse's robust construction and advanced materials allow it to withstand repeated stress cycles without degradation, ensuring consistent and reliable protection over an extended operational lifespan. This translates to reduced maintenance requirements and a lower total cost of ownership. Another key benefit of the Littelfuse LA70QS350-4 is its reduced watts loss. By minimizing the energy dissipated as heat during normal operation, this fuse contributes to cooler equipment temperatures. This not only enhances overall system efficiency but also reduces the thermal stress on adjacent components, further contributing to system reliability and potentially allowing for more compact equipment designs due to less need for extensive heat dissipation measures. The 700 Volt AC/DC rating provides exceptional design versatility, allowing engineers to implement this fuse across a wide spectrum of applications and voltage configurations without compromising safety or performance. This broad applicability makes the LA70QS350-4 a go-to choice for designers seeking a single, high-performance protection solution. Key Features and Benefits: * **Very Low I²t:** Offers enhanced protection for sensitive semiconductor devices against damaging fault currents. * **Superior Cycling Ability:** Ensures long, reliable life in high-cycling loading applications, reducing maintenance needs. * **Lower Watts Loss:** Promotes cooler operation, improving system efficiency and component longevity. * **700V AC/DC Rating:** Provides broad design flexibility for diverse power systems. * **Compact Size:** Facilitates equipment downsizing and space optimization. Applications: The Littelfuse LA70QS350-4 is ideally suited for the protection of 700 volt or less solid-state equipment, including but not limited to: * Motor Drives and Variable Frequency Drives (VFDs) * Uninterruptible Power Supplies (UPS) * Inverters and Converters * DC Power Supplies * Industrial Automation Equipment * Renewable Energy Systems (e.g., solar inverters) When selecting semiconductor fuses, professionals rely on manufacturers with a proven track record of quality and innovation. Littelfuse, a global leader in circuit protection, consistently delivers high-performance solutions that meet the evolving needs of the electronics industry. The LA70QS350-4 exemplifies this commitment, offering a robust and reliable solution for critical power protection.
  • Littelfuse LA70QS350-4 Very Fast-Acting Semiconductor Fuse
  • 700V AC/DC Voltage Rating for broad application compatibility
  • Extremely Low I²t for superior protection of sensitive solid-state devices
  • Superior cycling ability ensures long-term reliability in demanding applications
  • Lower watts loss for cooler operation and improved system efficiency
  • Compact size enables equipment downsizing and space optimization
  • Ideal for protecting motor drives, UPS, inverters, and other 700V or less solid-state equipment

Specifications

Application
Protection of Semiconductors
Brand Name
Littelfuse
Special Features
Very-Fast Acting
Standard
UL Recognized
Sub Brand
LA Series
Type
Semiconductor Fuse
Package Dimensions (L x W x H)
2 IN x 0.81 IN x 0.81 IN
Package Dimensions (L x W x H)
5.08 cm x 20.574 mm x 20.574 mm
Package Weight (Imperial)
0.200 L
Package Weight (Metric)
0.091 kg
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.