Mersen S1018318 - High Voltage DIN Back-up fuse for Transformer Limitor® VDE T402 12kVAC IEC 125A d78mm, L442mm With Thermal Striker 80N Low power losses
Mersen

S1018318

Alternate Item Number: 45DB120V125PTS3

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Overview

The Mersen S1018318 is a high-performance High Voltage DIN Back-up fuse, part of the Limitor® VDE T402 series, engineered for reliable transformer protection in high-voltage switchgear and controlgear. With a robust design and advanced features, this fuse ensures optimal safety and operational continuity. It operates at a rated voltage of 12 kVAC and a current rating of 125A, providing critical protection against the thermal and dynamic effects of short-circuits. The construction utilizes premium materials, including pure silver fuse-elements, copper caps coated with silver, and a durable ceramic body, ensuring longevity and superior performance. A key innovation in the Limitor®-PTS range is the new fuse-element design that significantly reduces power losses, contributing to improved energy efficiency. Furthermore, the integrated thermal striker, rated at 80N, actively prevents overheating within the fuse compartment of the switchgear, a common concern in high-voltage applications. This fuse is specifically designed for use in combination with air or gas-insulated switchgear, and is recommended by industry leaders like Siemens and Ormazabal for their gas-insulated switchgear applications. Its physical dimensions are d78mm in diameter and L442mm in length, with a cold resistance of 11.7 mΩ and a power dissipation of 340W at its rated current. The breaking capacity is rated at 40 kA, with a clearing I²t of 350 kA²s, ensuring swift and effective fault interruption. The Mersen S1018318 is manufactured in the US and is a testament to Mersen's decades of expertise in high-voltage protection solutions.
  • 12 kVAC Voltage Rating
  • 125A Current Rating
  • Limitor® VDE T402 Series
  • Integrated Thermal Striker (80N)
  • Low Power Losses with Silver Fuse-Elements

Specifications

AC Voltage Rating
12 kV
Amperage Rating
125 A
Application
Best used in SF6 insulated switch gear and compact switch gear HV Transformer protection
Body Material
Ceramic
Brand Name
Mersen
Connection
Cylindrical
Connection Material
Silver-Plated Copper
Interrupt Rating
80 kA
Mounting
Clip
Size
20 x 3.07 in
Size
508 x 78 mm
Special Features
Low switching voltage Large current ratings range Very low power losses Energy efficency New thermal striker patented by Mersen to prevent overheating Medium striker 80N / 30mm New cap design for a better compatibility with all types of clips and easier assembly Outdoor and indoor use Coordination with IEC 60787, IEC 62271-105 and VDE 0670 T303
Standard
IEC 60282-1 VDE 0670 part 4 VDE 0670 part 402 DIN 43625
Sub Brand
Limitor®
Type
DIN HV Back-up Fuses for Transformers
Type Of Indicators
Striker
Package Dimensions (L x W x H)
20 in x 3.07 in x 3.07 in
Package Dimensions (L x W x H)
508 mm x 78 mm x 78 mm
Package Weight (Imperial)
11.244 lb
Package Weight (Metric)
5.100 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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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 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.