Littelfuse TSS421 - The TSS Series is a totally solid-state timing module. Its 1A rated, solid-state output provides an excellent method of time control for exposures, dispensing, or for increasing or decreasing a switch closure. Time delays from 0.05 to 600 seconds, in 4 ranges, cover 90% of all OEM applications. Factory calibration of fixed delays is ±5% and the repeat accuracy is ±2%. The TSS Series can be surface mounted with a single screw, or snapped on a 35mm DIN rail using the P1023-20 accessory adaptor. Operation (Single Shot): Voltage must be applied before and during timing. Upon momentary or maintained closure of the initiate switch, the output energizes for a measured interval of time. At the end of the delay, the output de-energizes. Opening or reclosing the initiate switch during timing has no affect on the time delay. The output will energize if the initiate switch is closed when input voltage is applied. Reset: Reset occurs when the time delay is complete and the initiate switch opens. Loss of input voltage resets the time delay and output.
Littelfuse

TSS421

Alternate Item Number: TSS421

UPC: 079458023657

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Overview

The Littelfuse TSS421 (SKU: TSS421) is a totally solid-state timing module designed for precise time control in industrial applications. This module features a 1A rated, solid-state output, providing an effective method for controlling exposures, dispensing operations, or modifying switch closure durations. The TSS421 offers an externally adjustable time delay range from 0.05 to 3 seconds, covering a significant portion of OEM application requirements. Its analog circuitry ensures accuracy, with factory calibration at ±5% and a repeat accuracy of ±2%. The module is encapsulated to protect against shock, vibration, and humidity, ensuring longevity and dependable operation without moving parts that can arc or wear out. Installation flexibility is a key benefit, as the TSS421 can be surface mounted with a single screw or snapped onto a 35mm DIN rail using the P1023-20 accessory adaptor. Operation is single-shot: input voltage (120VAC) must be applied before and during timing. Upon closure of the initiate switch (momentary or maintained), the output energizes for the set interval. The output de-energizes at the end of the delay. Opening or reclosing the initiate switch during the timing interval has no effect. The output will energize if the initiate switch is closed when input voltage is applied. Reset occurs when the time delay is complete and the initiate switch opens, or upon loss of input voltage, which also resets the time delay and output. Compatible accessories include the P1004-95 Versa-Pot for remote adjustment, P1023-6 mounting bracket, P0700-7 Versa-Knob, and P1015-64 female quick connects. This module is ideal for automation, process control, and timing applications requiring dependable, solid-state timing solutions.
  • Totally solid-state timing module with 1A output
  • Externally adjustable time delay from 0.05 to 3 seconds
  • 120VAC input voltage
  • ±5% factory calibration and ±2% repeat accuracy
  • Surface or 35mm DIN rail mounting options

Specifications

Brand Name
Littelfuse
Mounting
Surface mount with one #10 (M5 x 0.8) screw Mount
Number Of Poles
Surface mount with one #10 (M5 x 0.8) screw
Operating Temperature
-40 to 75 F
Operating Temperature, Maximum
75 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.