Mersen S300373 - Square Body High-Speed Fuse Protistor® Size 30 aR 690VAC IEC 700VAC UL 50A With Striker Flush ends metric threads
Mersen

S300373

Alternate Item Number: PC30UD69V50TF


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Overview

The Mersen S300373 Protistor® Size 30 aR square body high-speed fuse-link is engineered for semiconductor protection in power conversion equipment operating at 690VAC (IEC) / 700VAC (UL). This ultra-fast-acting fuse-link delivers precise fault interruption with a rated current of 50A and a breaking capacity of 200kA, making it ideal for protecting sensitive semiconductor devices such as diodes, thyristors, IGBTs, and MOSFETs. The fuse-link features metric threads with flush ends for secure mounting and compatibility with global standards. Its silver-plated contact surfaces and non-magnetic hardware ensure low contact resistance and high reliability. The S300373 includes a striker for visual or mechanical trip indication, enabling remote monitoring or shutdown activation via a microswitch. With a power dissipation of 9W at rated current and a package weight of 0.30kg, this fuse-link is optimized for compact, high-performance power electronics applications. Designed for seamless integration into industrial automation, renewable energy systems, and motor drives, the Protistor® series offers unmatched protection against overcurrent events while minimizing downtime and equipment damage. The fuse-link’s aR (ultra-fast) characteristic ensures rapid response to fault conditions, reducing I²t values to protect downstream components effectively.
  • Rated current: 50A at 690VAC (IEC) / 700VAC (UL)
  • Breaking capacity: 200kA for superior fault interruption
  • Ultra-fast aR characteristic for semiconductor protection (IGBT, MOSFET, diodes, thyristors)
  • Square body with metric threads and flush ends for secure mounting
  • Includes striker for trip indication and remote monitoring via microswitch

Specifications

AC Voltage Rating
700 V
Amperage Rating
50 A
Application
Protection of inverters, motor drives, UPS systems and similar 690V or less equipments.
Brand Name
Mersen
Case
Ceramic
Connection
End Contact with Threaded Holes
Mounting
Bolted
Size
1.99 x 1.57 x 1.89 in
Size
50.6 x 40 x 48 mm
Special Features
Multiple body sizes and terminals or blades combination aR Class according to IEC 60269-4 and VDE 636-23 Very low I²t for improved semiconductor protection Ultra fast acting Current limiting Superior cycling capability
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
700 V
Wattage
9 W
Package Dimensions (L x W x H)
1.99 in x 1.57 in x 1.89 in
Package Dimensions (L x W x H)
50.6 mm x 40 mm x 48 mm
Package Weight (Imperial)
0.543 lb
Package Weight (Metric)
0.246 kg
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Fuse Block 600VAC 600VDC Class CC 30A 1/4in Quick Connect / Solder 90 angle screw Knob Panel Mount
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
Fuse Holder Modulostar® Size 10x38 IEC 690VAC 690VDC 3-Pole IP20

E1062696

Fuse Holder Modulostar® Size 10x38 IEC 690VAC 690VDC 3-Pole IP20
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.
9F61 Size B Clips 1.6in

9F61BWW460

9F61 Size B Clips 1.6in

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.