Littelfuse ASTUD3 - The ASQU and ASTU Series of 17.5 mm, knob adjustable, universal solid-state timers offer multiple functions, voltages, and time delay ranges. Choose one of 5 functions and 4 time delay ranges via 4 selection switches located on face of the unit. Adjustment through the time range is accomplished by an onboard knob. The ASQU Series has quick connect terminals and the ASTU Series has terminal blocks.
Littelfuse

ASTUD3

Alternate Item Number: ASTUD3

UPC: 079458991550

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Minimum Qty: 10

Multiplier: 10

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Overview

The Littelfuse ASQU and ASTU Series of 17.5 mm knob-adjustable universal solid-state timers (SKU: ASTUD3) represent a pinnacle of precision and versatility in industrial timing control. Engineered for demanding applications, these timers offer a robust solution for automating processes, controlling machinery, and ensuring accurate sequencing in various industrial environments. Their compact 17.5 mm footprint is a significant advantage, allowing for high rail density and efficient use of panel space, a critical consideration in modern industrial control cabinets. At the core of the ASQU and ASTU Series is a microcontroller-based design, ensuring exceptional repeat accuracy of +/- 1%. This reliability is further enhanced by integrated watchdog circuitry, which provides self-monitoring and self-correcting capabilities, guaranteeing consistent performance and minimizing downtime. Users can select from five distinct timing functions and four different time delay ranges using simple, intuitive switches located on the unit's face. Fine-tuning the time delay within the selected range is effortlessly accomplished via an onboard knob, offering field adjustability from 0.1 seconds to 100 minutes. This flexibility significantly reduces stocking requirements for distributors and end-users alike, as a single unit can serve multiple timing needs. The ASQU Series is equipped with convenient quick-connect terminals, facilitating rapid and secure connections, while the ASTU Series features robust terminal blocks for more traditional wiring methods. Both configurations are designed for ease of installation. The solid-state output is rated for 0.7A steady current and 10A inrush, capable of handling a wide range of loads and providing an impressive 100 million operations under typical conditions. The universal AC or DC voltage input, available in 24 to 240VAC or 9 to 110VDC models, further enhances their adaptability across different power systems. Each unit includes mounting fasteners for both surface and DIN rail mounting, offering installation flexibility. The Littelfuse ASTUD3 timers are ideal for applications such as motor control, conveyor systems, lighting control, pump sequencing, and general process automation where precise and reliable timing is paramount. Trust Littelfuse for dependable, high-performance timing solutions that streamline operations and enhance industrial efficiency.
  • 17.5 mm compact size for high rail density
  • Microcontroller-based with +/- 1% repeat accuracy
  • 5 selectable timing functions and 4 time delay ranges
  • Field adjustable knob for time delay from 0.1s to 100m
  • Universal AC/DC voltage input (24-240VAC or 9-110VDC)

Specifications

Brand Name
Littelfuse
Mounting
Two base adaptors are available Mount
Number Of Poles
Two base adaptors are available
Operating Temperature
-40 to 60 F
Operating Temperature, Maximum
60 F
Operating Temperature, Minimum
-40 F
Special Features
10Y WARR
Standard
CE/UR/CSA
Sub Brand
SSAC
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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.