Littelfuse HRDS313M - The HRDS Series combines an electromechanical relay output with microcontroller timing circuitry. It offers 12 to 230V operation in five options and factory fixed, onboard or external adjustable time delays with a repeat accuracy of ±0.5%. The output contact rating allows for direct operation of heavy loads, such as compressors, pumps, blower motors, heaters, etc. This series is ideal for OEM applications where cost is a factor. Operation (Single Shot): Input voltage must be applied before and during timing. Upon momentary or maintained closure of the initiate switch, the output relay 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 is opened. Loss of input voltage resets the time delay and output.
Littelfuse

HRDS313M

Alternate Item Number: HRDS313M

UPC: 079458993998

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Minimum Qty: 10

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Overview

The Littelfuse HRDS313M is a cost-effective single-shot timer relay from the HRDS Series, engineered for OEM applications requiring precise timing control of heavy industrial loads. This electromechanical relay integrates microcontroller-based timing circuitry with isolated 30A SPDT (NO/NC) contacts, enabling direct operation of compressors, pumps, blower motors, heaters, and other high-current devices without additional contactors. Designed for versatility, the HRDS313M supports input voltages from 12 to 230V AC/DC in five configurations (12/24VDC, 24/120/230VAC), making it compatible with global power systems. Time delays are factory-fixed, onboard-adjustable, or externally adjustable via accessories like the Versa-Pot potentiometer (P1004-95), allowing seamless integration into existing control panels. With a repeat accuracy of ±0.5% or ±20ms (whichever is greater) and a factory calibration tolerance of ±1% or ±5%, this relay delivers consistent performance under varying conditions. The relay’s encapsulated design protects against shock, vibration, and humidity, ensuring reliability in harsh industrial environments. Its compact footprint and low power consumption (≤4VA AC, ≤2W DC) optimize space and energy efficiency in control cabinets. Reset occurs automatically upon delay completion or loss of input voltage, while the single-shot operation mode ensures the output energizes for a preset interval upon switch closure, unaffected by subsequent switch actions during timing. Ideal for automation, HVAC, and machinery control systems, the HRDS313M combines durability, precision, and affordability in a single package. Compatible with DIN rail mounting (via P1023-20 adapter) and featuring 0.25in (6.35mm) quick-connect terminals for strain relief, this relay simplifies installation and maintenance. For remote adjustment, pair it with the Versa-Knob (P0700-7) and Versa-Pot (P1004-95) for precise time delay tuning without opening the enclosure.
  • Microcontroller-based timing with ±0.5% repeat accuracy for precise control
  • Isolated 30A SPDT (NO/NC) contacts for direct heavy-load operation (compressors, pumps, heaters)
  • Wide input voltage range: 12/24VDC or 24/120/230VAC with ±20% tolerance
  • Factory-fixed, onboard, or external time delay adjustment (0.1s–100m in 5 ranges)
  • Encapsulated design resists shock, vibration, and humidity for industrial durability

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 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.