Mersen S300603 - Square Body High-Speed Fuse Protistor® Size 70 aR 1250VAC IEC 1300VAC UL 125A With Striker Open Slot Blades
Mersen

S300603

Alternate Item Number: PC70UD13C125EF


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Specification Sheet

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Overview

The Mersen Protistor® S300603 is a high-speed fuse-link designed for semiconductor protection in demanding power conversion applications. This Size 70 aR fuse operates at 1250VAC (IEC) / 1300VAC (UL) with a rated current of 125A, offering ultra-fast response to protect sensitive semiconductor devices such as diodes, thyristors, GTOs, and IGBTs. The square body design ensures compatibility with multiple mounting styles, providing flexibility in equipment design while maintaining high interrupting ratings up to 126kA. Key features include pure silver fuse elements embedded in solidified sand for superior arc control, resulting in lower I²t values and enhanced protection. All contact surfaces are silver-plated for optimal conductivity, and non-magnetic hardware ensures reliability in high-frequency applications. The fuse-link can be equipped with a low-voltage trip indicator that activates a field-mountable microswitch for remote monitoring. With a power dissipation of 38W at rated current and a package weight of 0.36kg, the S300603 is optimized for compact yet high-performance installations. Ideal for use in industrial power supplies, motor drives, renewable energy inverters, and other high-power electronics where semiconductor protection is critical. The striker open slot blades enable easy integration into existing systems, while compliance with IEC 1300VAC and UL 125A standards ensures global compatibility. Choose Mersen Protistor® for reliable, high-speed protection in your most demanding applications.
  • Rated current: 125A, voltage: 1250VAC (IEC) / 1300VAC (UL)
  • Ultra-fast aR response for semiconductor protection (diodes, thyristors, IGBTs)
  • Square body design with striker open slot blades for flexible mounting
  • Pure silver fuse elements in solidified sand for controlled arcing and low I²t
  • Silver-plated contacts, non-magnetic hardware, and optional trip indicator

Specifications

AC Voltage Rating
1300 V
Amperage Rating
125 A
Application
Protection of inverters, motor drives, UPS systems and similar 690V or less equipments.
Brand Name
Mersen
Case
Ceramic
Connection
Open Slot Blades
Connection Type
Open Slot Blades
Current Rating
125A
Material
Pure silver, Sand, Non-magnetic hardware
Mounting
Bolted
Series
Protistor®
Size
4.86 x 1.57 x 1.95 in
Size
123.4 x 39.8 x 49.5 mm
Size
Size 70
Special Features
Multiple body sizes and terminals or blades combination aR Class according to VDE 636-23 and IEC 60269-4 Very low I²t for improved semiconductor protection Ultra fast acting Current limiting Superior cycling capability Increased technical performances: higher ratings and reduction in volume and weight
Standard
IEC 60269-4 Compliance UL/CSA Recognized E76491 CCC GB 13539.4 for Asian market only
Sub Brand
Protistor®
Type
Square Body High-Speed Fuse-Links AC Protection
Type Of Indicators
Striker
Voltage Rating
1300 V
Voltage Rating
1250VAC / 1300VAC
Wattage
38 W
Package Dimensions (L x W x H)
4.86 in x 1.57 in x 1.95 in
Package Dimensions (L x W x H)
123.4 mm x 39.8 mm x 49.5 mm
Package Weight (Imperial)
0.789 lb
Package Weight (Metric)
0.358 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.

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 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.