Littelfuse TRDU120A3 - The TRDU Series is a versatile universal time delay relay with 21 selectable single and dual functions. The dual functions replace up to three timers required to accomplish the same function. Both the function and the timing range are selectable with switches located on the face of the unit. Two LED's indicate input voltage and output status. This device offers full 10A isolated relay output contacts in either SPDT or DPDT. The TRDU replaces hundreds of part numbers, thereby, reducing your stock inventory requirements. 21 Functions: Five switches are provided to set one of 10 single or 11 dual modes of operation. See datasheet for a complete list of singe and dual functions.
Littelfuse

TRDU120A3

Alternate Item Number: TRDU120A3

UPC: 079458011135


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Minimum Qty: 10

Multiplier: 10

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Overview

The Littelfuse TRDU120A3 universal time delay relay delivers precision timing control for industrial automation, process control, and machinery applications. Designed as a versatile replacement for multiple timers, this microcontroller-based relay offers 21 selectable single and dual functions—eliminating the need for up to three separate timers and reducing stock inventory by hundreds of part numbers. The TRDU120A3 features switch-selectable timing ranges from 0.1 seconds to 1,705 hours across eight adjustable scales, with repeat accuracy of ±0.1% or 20ms (whichever is greater). Its 10A isolated relay output contacts (SPDT or DPDT) handle resistive loads up to 1/3 hp at 120/240VAC or 28VDC, ensuring compatibility with AC or DC control circuits. Dual LEDs provide clear visual indication of input voltage and relay status, while front-panel switches enable effortless function and timing configuration. With a compact 76.7mm x 60.7mm x 45.2mm footprint and plug-in socket mounting (11-pin DPDT), the TRDU120A3 integrates seamlessly into 35mm DIN rail or surface-mounted systems. Operating from 120VAC input with ±20% tolerance, it consumes ≤3W and supports 50/60Hz AC line frequencies. Ideal for applications requiring delayed start, interval timing, recycling, or single-shot operations, this relay combines flexibility, durability, and efficiency in a single, cost-effective solution. Compatible with accessories like NDS-11 sockets and PSC11 hold-down clips, the TRDU120A3 is built for demanding industrial environments (-20°C to 65°C operating range).
  • 21 selectable single and dual timing functions for versatile control
  • Switch-selectable timing range: 0.1s to 1,705h across 8 ranges
  • 10A isolated relay output (SPDT or DPDT) for AC/DC loads up to 1/3 hp
  • Microcontroller-based with repeat accuracy of ±0.1% or 20ms
  • Dual LED indicators for input voltage and relay status

Specifications

Brand Name
Littelfuse
Connection Type
Plug-in socket (11-pin DPDT)
Current Rating
10 A
Frequency
50/60 Hz
Mounting
Plug-in socket Mount
Mounting Type
DIN rail or surface-mounted
Mounting Type
35mm DIN rail or surface-mounted
Number Of Poles
Plug-in socket
Operating Temperature
-20 to 65 F
Operating Temperature, Maximum
65 F
Operating Temperature, Minimum
-20 F
Poles
SPDT or DPDT
Poles
SPDT/DPDT
Series
TRDU
Size
76.7mm x 60.7mm x 45.2mm
Special Features
10Y WARR
Standard
CE/UR/CSA
Sub Brand
SSAC
Voltage Rating
120 VAC
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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.