Mersen N209312 - High Voltage DIN Back-up fuse for Transformer Limitor® VDE T4 12kVAC IEC 50A d56mm, L292mm With Striker Standard 80N
Mersen

N209312

Alternate Item Number: 45DB120V50P

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Overview

The Mersen N209312 is a high-voltage DIN back-up fuse specifically designed for the reliable protection of transformers against short-circuit currents. As part of the Limitor®-P series, this fuse adheres to the IEC 60282-1 standard for back-up fuses. Engineered for demanding electrical systems, it operates at 12kVAC and features a 50A rated current. The fuse construction utilizes premium materials to ensure longevity and performance: fuse elements are made of pure silver, caps are silver-coated copper, and the body is constructed from durable ceramic. This specific model has a diameter of 56mm and a length of 292mm, with an integrated striker mechanism providing a standard 80N force. Key specifications include a breaking capacity of 63 kA, an I²t value of 50 kA²s, and a minimum breaking current of 205 A. The cold resistance is rated at 26 mΩ, with a power dissipation of 106 W at its rated current. Mersen's Limitor® fuses have a proven track record of decades of reliable service in high-voltage switchgear, controlgear, and various high-voltage systems. The N209312 is manufactured in the USA and is compliant with German VDE 0670 T402 standards for DIN HV back-up fuses for transformers. Its robust design and high-quality components make it an essential safety device for safeguarding critical transformer assets from damaging overcurrent events.
  • Designed for transformer protection against short-circuit currents
  • 12kVAC rated voltage, 50A rated current
  • IEC 60282-1 compliant back-up fuse
  • Durable construction: pure silver elements, silver-coated copper caps, ceramic body
  • Includes striker mechanism (80N standard)

Specifications

AC Voltage Rating
12 kV
Amperage Rating
50 A
Application
HV Transformer protection
Body Material
Ceramic
Brand Name
Mersen
Connection
Cylindrical
Connection Material
Silver-Plated Copper
Current Rating
50 A
Interrupt Rating
63 kA
Material
Ceramic, Silver, Copper
Mounting
Clip
Series
Limitor® VDE T4
Size
14.09 x 2.2 in
Size
358 x 56 mm
Size
d56mm, L292mm
Special Features
High breaking capacity High current limitation Low switching voltage Quick breaking Medium striker 80N/30mm Indoor and outdoor applications Energy efficency New cap design for a better compatibility with all types of clips and easier assembly Coordination with IEC 60787, IEC 62271-105, IEC/TR 62655
Standard
IEC 60282-1 VDE 0670 part 4 DIN 43625
Sub Brand
Limitor®
Type
DIN HV Back-up Fuses for Transformers
Type Of Indicators
Striker
Voltage Rating
12 kVAC
Package Dimensions (L x W x H)
14.09 in x 2.2 in x 2.2 in
Package Dimensions (L x W x H)
358 mm x 56 mm x 56 mm
Package Weight (Imperial)
3.748 lb
Package Weight (Metric)
1.700 kg
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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.

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Frequently Asked Questions about Mersen

What industries and applications are Mersen products used for?

Mersen products are used across diverse industrial sectors including solar power, electric vehicles, buildings/construction, industrial automation, power distribution, HVAC, elevators, telecommunications, and specialty manufacturing. Key application areas include circuit protection, surge protection, battery module protection, electrical safety systems, and power management for residential, commercial, and utility-scale installations.

What are the main product lines offered by Mersen?

Mersen offers five primary electrical power product lines: IEC and UL/CSA Fuses and Fusegear, Surge Protection, Low Voltage Disconnect Switches, Power Distribution Blocks, and Engineered Solutions. Their comprehensive range includes specialized components like high-speed fuses, modular fuse holders, surge arresters, and custom-engineered electrical protection systems for industrial and power management applications.

What are the key features of Mersen products?

Mersen products feature advanced electrical protection and power management solutions with key characteristics including finger-safe design, compact modularity, and high-performance safety features. Their product lines span electrical power components like fuses, surge protection, power distribution blocks, and specialized solutions for industrial, solar, and building applications. Critical features include UL/CSA approvals, high short-circuit current ratings, and innovative technologies like the Fuse Control™ program that minimize electrical risks and optimize system performance.

What environmental ratings do Mersen products have?

Mersen products meet rigorous environmental ratings across multiple standards, including UL 508A Type 1, 2, 3, 4, 4X, 12, and 13, CSA Type 1, 2, 3, 4, 4X, 12, and 13, and NEMA Type 1, 2, 3, 4, 4X, 12, and 13. They feature IEC 60529 IP66 protection, with enhanced UV inhibitors for outdoor weathering and operating temperatures ranging from -40°C to 130°C (-40°F to 266°F). These ratings ensure superior protection in wet, corrosive, and challenging industrial environments.

What accessories are available for Mersen products?

Mersen offers multiple accessories for their fuse blocks and systems, including safety pullers (DFC3M and DFC3LP), DIN-rail adapters (DRM), bus bars, auxiliary contacts, and specialized mounting hardware. Key accessories include the DFC3M safety puller for 1-1/2" x 13/32" midget or Class CC fuses, the DRM adapter for mounting 303 series fuse blocks on DIN-rail, and UltraSafe fuse module accessories like bus bars and auxiliary contacts that enable module interconnection and monitoring.

How are Mersen products typically installed?

Mersen products are typically installed in electrical distribution systems, control panels, and industrial automation environments using multiple mounting options. These include service entrance panel mounting, distribution panel installation, control panel DIN rail mounting, and custom engineered solutions like Fused Coordination Panelboards. Installation depends on the specific product type, such as fuses, surge protective devices, or switches, and is designed to provide electrical protection and circuit safety in various industrial and commercial applications.

What certifications and standards do Mersen products comply with?

Mersen products are certified to multiple international standards, including UL (Underwriters Laboratories), CSA (Canadian Standards Association), CCC (China Compulsory Certification), and EAC (Eurasian Conformity). Our products meet rigorous safety and performance standards for industrial applications across North America, China, Russia, and other global markets, ensuring compliance and reliability in electrical power and advanced materials solutions.

What technical support does Mersen offer?

Mersen provides comprehensive technical support through multiple channels, including technical experts located in your time zone who can assist with product selection, application guidance, and troubleshooting. Their Fuse Control™ program offers a free Fuse Inventory Audit & Analysis, and customers can access technical resources through their sales representatives and online platform ep.mersen.com.