Littelfuse LSRX-C - The LSRX is an AC current sensor designed to energize the output contact whenever 4.5 Amps or greater is present. The LSRX is used commonly as an AC current proof relay to indicate if a motor is operating. It can also be used to interlock fans, compressors and motors; to indicate equipment status such as feed rates, tool wear, loss of prime on pumps, mixer viscosity and all types of current sensing conditions or to stage pump motors, chillers, or other machinery. This device combines a current transformer (CT), transducer and high current output relay together to switch alarm circuits, contactors and most resistive or inductive loads. The LSRX can perform the function of an auxiliary contact, yet has the advantages of universal application and isolation.
Littelfuse

LSRX-C

Alternate Item Number: LSRX-C

UPC: 079458996883


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Overview

The Littelfuse LSRX-C (SKU: LSRX-C) is an AC current sensor designed to provide reliable equipment status indication and control. This device energizes its output contact when a current of 4.5 Amps or greater is detected, functioning as an AC current proof relay. It is commonly employed to verify motor operation, ensuring that machinery is actively running. The LSRX-C is also integral for interlocking systems, preventing unintended operation of fans, compressors, and motors by confirming their active state. Its utility extends to monitoring critical equipment parameters such as feed rates, detecting tool wear, identifying loss of prime on pumps, and assessing mixer viscosity. The integrated design combines a current transformer (CT), a transducer, and a high-current output relay within a single unit. This allows the LSRX-C to directly switch alarm circuits, contactors, and a broad range of resistive or inductive loads, simplifying installation and reducing component count. Offering universal application and electrical isolation, the LSRX-C can effectively serve the function of an auxiliary contact while providing enhanced flexibility and safety. It is a practical solution for staging operations of pump motors, chillers, and other industrial machinery requiring precise current-based control and monitoring. Manufactured in the US.
  • Activates output contact at 4.5 Amps AC or greater
  • Functions as an AC current proof relay for motor operation verification
  • Used for interlocking fans, compressors, and motors
  • Monitors equipment status like feed rates, tool wear, and pump prime
  • Combines CT, transducer, and high-current output relay in one unit

Specifications

Brand Name
Littelfuse
Current Rating
4.5 A
Mounting
Surface mount
Number Of Poles
Surface mount
Operating Temperature
-4 to 158
Operating Temperature, Maximum
158
Operating Temperature, Minimum
-4
Pickup Voltage
5 V
Standard
UL/CE
Sub Brand
Symcom
Package Dimensions (L x W x H)
2.5 IN x 1.13 IN x 2.7 IN
Package Dimensions (L x W x H)
63.5 mm x 28.7 mm x 68.6 mm
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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.