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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 The ASQU and ASTU Series of 17.5 mm, knob adjustable, universal solid-state timers offer…

Alternate Item Number: ASTUD3

UPC: 079458991550


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Contact for Pricing

Minimum Qty: 10

Multiplier: 10

*Contact for lower quantities*

Call +1 (262) 252-1600 (toll-free 877-268-3700) or email [email protected] for pricing and availability.

Overview

The Littelfuse ASTUD3, part of the ASQU and ASTU Series, is a 17.5mm knob-adjustable universal solid-state timer designed for precise industrial timing control. This microcontroller-based unit offers exceptional repeat accuracy of +/-1% and features a universal input accepting 24-240VAC or 9-110VDC, simplifying inventory by eliminating the need for multiple voltage-specific units. Users can select from five distinct timing functions and four time delay ranges, adjustable from 0.1 seconds to 100 minutes, via four intuitive selection switches on the unit's face. Fine-tuning of the time delay is accomplished using a front-mounted knob with a 1-100 reference dial. The ASQU Series is equipped with quick-connect terminals for rapid wiring, while the ASTU Series features robust terminal blocks for traditional connections. Both series provide a solid-state output rated for 0.7A steady and 10A inrush, offering 100 million typical operations. Mounting flexibility is ensured with included fasteners for both surface and DIN rail mounting. Watchdog circuitry provides self-monitoring and self-correction for enhanced reliability. Typical applications include motor control, conveyor systems, lighting sequencing, pump control, and general process automation where accurate and repeatable timing is critical. The compact 17.5mm footprint maximizes panel density.
  • 17.5mm compact size for high rail density
  • Universal input: 24-240VAC or 9-110VDC
  • 5 selectable timing functions
  • 4 selectable time delay ranges: 0.1s - 100m
  • Knob-adjustable time delay with 1-100 reference dial
  • Solid-state output: 0.7A steady, 10A inrush
  • Repeat accuracy: +/-1%
  • Includes surface and DIN rail mounting adapters
  • Watchdog circuitry for self-monitoring and correction
  • Available with quick-connect terminals (ASQU) or terminal blocks (ASTU)

Specifications

Brand Name
Littelfuse
Mounting
Two base adaptors are available Mount
Mounting
Two base adaptors are available
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

What timing functions are available in the ASQU/ASTU Series?

The series offers five timing functions including retriggerable single shot, delay on operate, delay on release, interval, and one-shot. Functions are selected via onboard DIP switches.

What are the mechanical life ratings of the ASTUD3?

The relay offers 10 million mechanical operations and 1 million electrical operations. The solid-state design provides 100 million typical operations.

What mounting options are available for the ASTUD3?

Each unit includes mounting fasteners for both surface and DIN rail mounting. The compact 17.5mm footprint maximizes panel density.

What accessories are available for the ASQU/ASTU Series?

Accessories include female quick-connect terminals (AWG 10/12, 14/16, 18/22), surface mount adapter (P0500-178), and DIN rail mount adapter (P0500-179).

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.