Mersen S300718 - Square Body High-Speed Fuse Protistor® Size 73 aR 850VAC IEC 900VAC UL 1400A With Striker Flush ends metric threads
Mersen

S300718

Alternate Item Number: PC73UD85V14CTF


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Specification Sheet

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Overview

The Mersen S300718 Protistor® Size 73 aR high-speed fuse-link delivers ultra-fast semiconductor protection for power conversion equipment operating at 850VAC (IEC) / 900VAC (UL). Designed for demanding applications, this 1400A fuse-link features a square body with flush ends and metric M12 threaded terminals, ensuring compatibility with global mounting standards. Engineered with die-cut fuse elements embedded in solidified sand, it controls arcing for lower I²t values and high interrupting ratings up to 150kA. Pre-arcing I²t is 755 kA²s, while clearing I²t reaches 3700 kA²s, providing precise fault interruption. Power dissipation at rated current is 210W, with a package weight of 1.25kg. All contact surfaces are silver-plated, and hardware is non-magnetic for enhanced conductivity and corrosion resistance. Optional low-voltage trip indicators with microswitch activation enable remote fault signaling. Available in multiple body sizes and mounting styles, the Protistor® series supports diodes, thyristors, and IGBT devices in industrial drives, UPS systems, and renewable energy inverters. Compliance with IEC 60269-4 and UL 248-14 standards ensures global market acceptance. The S300718 is ideal for equipment requiring high-speed fault protection with metric thread compatibility and striker activation for visual/tactile fault indication.
  • Rated current: 1400A with 850VAC (IEC) / 900VAC (UL) operation
  • Ultra-fast aR response with pre-arcing I²t 755 kA²s and clearing I²t 3700 kA²s
  • Square body with flush ends and metric M12 threaded terminals for global compatibility
  • High interrupting rating: 150kA with power dissipation of 210W at rated current
  • Silver-plated contacts, non-magnetic hardware, and optional striker/trip indicator

Specifications

AC Voltage Rating
900 V
Amperage Rating
1400 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
2.91 x 2.87 x 3.09 in
Size
74 x 73 x 78.5 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
900 V
Wattage
210 W
Package Dimensions (L x W x H)
2.91 in x 2.87 in x 3.09 in
Package Dimensions (L x W x H)
74 mm x 73 mm x 78.5 mm
Package Weight (Imperial)
2.690 lb
Package Weight (Metric)
1.220 kg
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GPM-SRR90

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.