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Littelfuse TDM24AL - The TDM/TDMH/TDML Series is a delay-on-make timer that combines accurate digital circuitry with isolated, DPDT relay contacts in an industry standard 8-pin plug-in package. DIP switch adjustment allows precise selection of the time delay over the full time delay range. The TDM/TDMH/TDML Series is the product of choice for custom control panel and OEM designers. Operation (Delay-on-Make): Upon application of input voltage, the time delay begins. The output is de-energized before and during the time delay. At the end of the time delay, the output relay energizes and remains energized until input voltage is removed. Reset: Removing input voltage resets the time delay and output.

Littelfuse TDM24AL The TDM/TDMH/TDML Series is a delay-on-make timer that combines accurate digital…

Alternate Item Number: TDM24AL

UPC: 079458999655


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

Overview

The Littelfuse TDM24AL is a precision delay-on-make timer designed for industrial control panels and OEM applications requiring accurate timing sequences. This 8-pin plug-in unit operates on 24V AC input and features isolated DPDT relay contacts rated for 10A, enabling control of both AC and DC loads. The time delay is user-selectable from 1 to 1023 seconds in 1-second increments via DIP switches, allowing for precise tuning to specific operational requirements. The TDM24AL leverages microcontroller-based digital circuitry to deliver a repeat accuracy of +/- 0.1% and a first-time setting accuracy of +/- 2%, ensuring consistent and reliable performance across applications. Upon application of input voltage, the output relay remains de-energized during the programmed delay period. Once the set time elapses, the DPDT relay energizes and maintains its state until input voltage is removed, at which point the timer resets automatically. This timer is ideal for sequencing operations, managing inrush currents, or allowing systems to stabilize before activation. The integrated LED provides clear visual indication of the time delay status, simplifying monitoring and troubleshooting. Compatible with industry-standard 8-pin octal sockets such as the Littelfuse OT08PC or P1011-6, the TDM24AL simplifies installation and integration into existing control systems. The series includes models with extended delay ranges (TDMH for 10–10,230 seconds in 10-second increments) and sub-second precision (TDML for 0.1–102.3 seconds in 0.1-second increments), offering flexibility for diverse timing needs. Key applications include motor control sequencing, conveyor systems, lighting control, HVAC systems, and automated machinery where precise delay-on-make functionality is critical. The compact 8-pin plug-in package adheres to industry standards, making it a preferred choice for custom panel builders and OEM designers seeking reliable, easy-to-integrate timing solutions.
  • 24V AC input voltage with 1-1023 second delay range (1-second increments)
  • Isolated DPDT relay contacts rated 10A for AC/DC load control
  • Microcontroller-based design with +/- 0.1% repeat accuracy and +/- 2% setting accuracy
  • Integrated LED for visual time delay status indication
  • Compatible with 8-pin octal sockets (OT08PC, P1011-6) for easy installation

Specifications

Brand Name
Littelfuse
Connection Type
Plug-in (8-pin octal)
Current Rating
10A
Mounting
Plug-in socket Mount
Mounting Type
Plug-in (8-pin octal socket)
Number Of Poles
Plug-in socket
Operating Temperature
-20 to 65 F
Operating Temperature, Maximum
65 F
Operating Temperature, Minimum
-20 F
Poles
DPDT
Series
TDM/TDMH/TDML
Special Features
10Y WARR
Standard
CE/UR/CSA/UL
Sub Brand
SSAC
Voltage Rating
24V AC
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Frequently Asked Questions

What types of fuses does Littelfuse offer for industrial applications?

Littelfuse offers UL Class fuses, high-speed fuses, medium voltage fuses, 10 x 38 mm fuses, and solar fuses for industrial applications.

How do high-resistance grounding systems benefit industrial applications?

High-resistance grounding limits point-of-fault damage and eliminates arc-flash hazards and transit overvoltages associated with ground faults.

What protection do Littelfuse voltage monitors offer?

Voltage monitors provide protection against both supply line and load side faults when the motor is running.

What functions do Littelfuse timers and flashers control?

Timers and flashers delay starting and stopping loads, and control cycling and sequencing of motors, pumps, compressors, heaters, and lighting.

How do Littelfuse arc-flash protection relays enhance safety?

Arc-flash relays detect a developing arc-flash incident and send a trip signal to interrupt power before significant damage occurs.

What types of motor protection does Littelfuse provide?

Littelfuse offers voltage monitors, current monitors, and Bluetooth enhanced overload relays for low and medium voltage motor protection applications.

What do Littelfuse pump controllers protect against?

Pump controllers protect and disable a pump if a hazardous condition arises, with options for single-phase and three-phase applications.

What is the benefit of Littelfuse ground-fault protection relays?

Sensitive ground-fault relays with advanced filtering quickly and reliably detect insulation resistance breakdown caused by moisture, vibration, chemicals, or dust.

What does the Littelfuse trailing-cable protection relay monitor?

Trailing-cable protection relays continuously monitor the integrity of the ground conductor in portable cables to protect equipment from hazardous voltages.

What are Littelfuse fuse blocks and holders designed for?

Littelfuse fuse blocks and holders are selected by OEMs and designers for their compact designs, indication features, and DIN-rail mounting flexibility.

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.