Littelfuse 3E4PT.6 - Potential Transformer (PT) fuses are current limiting fuses with high interrupting ratings designed for the protection of potential transformers. Application Note: When applying fuses for the protection of transformers, the magnetizing current inrush must be considered. The characteristics of the inrush, which can be matched with a fuse’s time-current curve, should be available from the transformer manufacturer. Live Parts: Live parts are available for mounting potential transformer single, double, and triple barrel fuses. Note, all clips are sold in pairs.
Littelfuse

3E4PT.6

Alternate Item Number: 3E4PT.6

UPC: 079458043938


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Overview

The Littelfuse 3E4PT.6 Potential Transformer (PT) Fuse (SKU: 3E4PT.6) is a specialized current-limiting fuse engineered with a high interrupting rating, specifically designed for the critical protection of potential transformers in power distribution systems. Unlike standard fuses, these PT fuses are optimized to handle the unique magnetizing current inrush characteristics inherent to transformer operation, ensuring reliable performance without nuisance tripping. This fuse is part of Littelfuse's dedicated line of PT protection solutions, providing essential defense against overcurrent conditions and short circuits that could otherwise damage sensitive transformer equipment. Key specifications include compatibility with single, double, and triple barrel fuse mountings, offering installation flexibility for various potential transformer configurations. Live parts are available for mounting, with all clips sold in pairs. The 3E4PT.6 fuse's time-current curve is designed to be matched with the magnetizing inrush characteristics provided by the transformer manufacturer, enabling precise coordination to minimize operational disruptions and safeguard equipment. Applications for the 3E4PT.6 span industrial, utility, and commercial power systems where potential transformers are deployed for voltage measurement, metering, and protection relaying. The Littelfuse 3E4PT.6 fuse is a vital component in maintaining the integrity and longevity of power distribution infrastructure, reducing the risk of equipment failure and costly downtime. Trust Littelfuse, a U.S.-based manufacturer with decades of expertise in circuit protection, to deliver dependable performance in critical applications.
  • Current-limiting fuse designed for Potential Transformer (PT) protection
  • High interrupting rating for robust overcurrent and short circuit defense
  • Optimized to handle transformer magnetizing current inrush
  • Compatible with single, double, and triple barrel fuse mountings
  • Live parts available for mounting; clips sold in pairs

Specifications

Application
Transformers, potential transformers, feeders, and motor circuits
Brand Name
Littelfuse
Special Features
Current Limiting
Sub Brand
Medium Voltage
Type
Medium Voltage Fuses
Fuse Block 600VAC 600VDC Class CC 30A 1/4in Quick Connect / Solder 90 angle screw Knob Panel Mount

GPM-SRR90

Fuse Block 600VAC 600VDC Class CC 30A 1/4in Quick Connect / Solder 90 angle screw Knob Panel Mount
Fuse Holder Modulostar® Size 10x38 IEC 690VAC 690VDC 3-Pole IP20

E1062696

Fuse Holder Modulostar® Size 10x38 IEC 690VAC 690VDC 3-Pole IP20
Fuse Holder UltraSafe™ 800VAC 1000VDC UL Fuse size 14x51 1-Pole Visual Indicator Microswitch Pressure Plate IP20

C331156

Fuse Holder UltraSafe™ 800VAC 1000VDC UL Fuse size 14x51 1-Pole Visual Indicator Microswitch Pressure Plate IP20
Fuse Block 1500VAC 1500VDC 400A 1-Pole Stud M8

1SCM8

Fuse Block 1500VAC 1500VDC 400A 1-Pole Stud M8
9F61 Size B Clips 1.6in

9F61BWW460

9F61 Size B Clips 1.6in
POWR-JAW clamps improve the contact between fuse and clip. The unnecessary heat from poor contact due to the loss of spring force in the clips can cause nuisance fuse opening and premature aging of surrounding components. High temperature phenolic resin knob designed for the most severe environments 7 sizes to provide effective coverage. Simple design makes installation easy.

LCC5

POWR-JAW clamps improve the contact between fuse and clip. The unnecessary heat from poor contact due to the loss of spring force in the clips can cause nuisance fuse opening and premature aging of surrounding components. High temperature phenolic resin knob designed for the most severe environments 7 sizes to provide effective coverage. Simple design makes installation easy.

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.