Littelfuse SE-325ET - SE-325ET is a neutral-grounding resistor monitor with a supply voltage of 240 ac and a ground-fault trip level of 0.5–4.0 A.
Littelfuse

SE-325ET

Alternate Item Number: SE-325ET

UPC: 079458988239


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Overview

The Littelfuse SE-325ET neutral-grounding resistor monitor is a critical safety device engineered to protect industrial electrical systems from ground faults. Designed for applications requiring precise ground-fault detection, this monitor operates on a 240 VAC supply voltage and features an adjustable ground-fault trip level ranging from 0.5 to 4.0 A. Its primary function is to monitor the neutral-grounding resistor in ungrounded or high-resistance grounded systems, ensuring rapid detection of ground faults that could compromise equipment integrity or pose safety hazards. By providing immediate alerts or tripping mechanisms, the SE-325ET helps prevent catastrophic failures, reduces downtime, and safeguards personnel in industrial environments such as manufacturing plants, data centers, hospitals, and commercial buildings. Ground faults are among the most common yet dangerous electrical faults in industrial systems. Unlike phase-to-phase faults, ground faults can go undetected in ungrounded systems, leading to arcing, equipment damage, and fire risks. The Littelfuse SE-325ET addresses this challenge by continuously monitoring the current through the neutral-grounding resistor. When the ground-fault current exceeds the preset trip level (adjustable between 0.5 and 4.0 A), the monitor triggers an alarm or initiates a shutdown, depending on system configuration. This proactive approach ensures compliance with safety standards such as NEC, IEEE, and OSHA, while also meeting the stringent requirements of industrial insurance providers. One of the standout features of the SE-325ET is its versatility and ease of integration. The monitor is compatible with a wide range of neutral-grounding resistors and can be installed in both new constructions and retrofit projects. Its compact design and DIN-rail mounting capability make it suitable for space-constrained electrical panels. Additionally, the SE-325ET supports both analog and digital output options, allowing seamless integration with building management systems (BMS), SCADA systems, or PLCs for centralized monitoring and control. This flexibility makes it an ideal choice for facilities that require scalable and future-proof electrical safety solutions. Professionals in the electrical engineering and maintenance fields prioritize reliability, accuracy, and durability when selecting ground-fault monitoring equipment. Littelfuse, a globally recognized leader in circuit protection and electrical safety solutions, has built a reputation for delivering high-performance products that meet the demands of industrial applications. The SE-325ET is no exception, featuring a robust design that withstands harsh industrial environments, including exposure to dust, moisture, and temperature fluctuations. Its compliance with international safety standards, such as UL and CE, further underscores its reliability and suitability for global markets. Typical applications for the Littelfuse SE-325ET include: - **Manufacturing Facilities:** Protecting sensitive machinery and production lines from ground faults that could disrupt operations. - **Data Centers:** Ensuring uninterrupted power supply and preventing data loss due to electrical faults. - **Healthcare Facilities:** Maintaining the integrity of critical medical equipment and reducing the risk of electrical hazards in patient care areas. - **Commercial Buildings:** Enhancing safety in HVAC systems, lighting, and other electrical infrastructure. - **Renewable Energy Systems:** Monitoring ground faults in solar or wind power installations to prevent damage to inverters and other components. When selecting a neutral-grounding resistor monitor, professionals consider factors such as trip level adjustability, compatibility with existing systems, and ease of installation. The SE-325ET excels in all these areas, offering a user-friendly interface for setting trip levels and a straightforward wiring process. Additionally, Littelfuse provides comprehensive technical support and documentation, including wiring diagrams, application notes, and troubleshooting guides, to assist engineers and technicians in deploying the SE-325ET with confidence. In summary, the Littelfuse SE-325ET neutral-grounding resistor monitor is a trusted solution for industrial ground-fault protection. Its adjustable trip level, robust design, and seamless integration capabilities make it an invaluable addition to any electrical safety strategy. By investing in the SE-325ET, facilities can enhance operational safety, reduce downtime, and ensure compliance with regulatory standards—all while leveraging the expertise and reliability of a leading manufacturer in the electrical safety industry.
  • 240 VAC supply voltage for industrial compatibility
  • Adjustable ground-fault trip level (0.5–4.0 A) for customizable protection
  • Continuous monitoring of neutral-grounding resistor for early fault detection
  • Compact DIN-rail mounting design for easy installation in electrical panels
  • Supports analog and digital outputs for integration with BMS, SCADA, or PLCs
  • Compliant with UL, CE, NEC, IEEE, and OSHA safety standards
  • Robust construction for harsh industrial environments
  • Ideal for manufacturing, data centers, healthcare, and commercial facilities

Specifications

Application
Mining
Brand Name
Littelfuse
Current Rating
0.5–4.0 A
Mounting Type
DIN-Rail
Special Features
Continuous NGR monitoring
Sub Brand
SE 325 Series
Type
Trailing Cable Protection
Voltage Rating
240 Vac
Package Weight (Imperial)
1.980 L
Package Weight (Metric)
0.900 kg
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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.