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Mersen K302666 - Square Body High-Speed Fuse Protistor® Size 70 gR 450VDC IEC 500VDC UL 315A With Striker Flush ends metric threads

Mersen K302666 Square Body High-Speed Fuse Protistor® Size 70 gR 450VDC IEC 500VDC UL 315A With Striker…

Alternate Item Number: D70GB45V315TF


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Specification Sheet

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Overview

The Mersen Protistor® K302666 (SKU: K302666) is a high-speed fuse-link engineered for critical semiconductor protection in demanding industrial applications. This Size 70 gR fuse features a square body design and is rated for 450VDC, with IEC compliance up to 500VDC and UL compliance up to 500VDC. Its continuous current rating is 315A, making it ideal for safeguarding sensitive components like diodes, thyristors, GTOs, and IGBTs. Engineered for superior arc control, the K302666 utilizes pure silver fuse elements embedded in solidified sand, delivering optimized I²t performance. Key electrical specifications include a pre-arcing I²t of 16 kA²s and a clearing I²t of 129 kA²s. The fuse boasts a rated breaking capacity of 126 kA, ensuring robust protection against short circuits. Installation is facilitated by flush metric threaded ends, providing secure mounting. A built-in striker activates a microswitch upon fuse operation, enabling remote fault signaling. All contact surfaces are silver-plated, and non-magnetic hardware enhances reliability. This fuse is compatible with DIN110 blade terminals, offering flexibility for global installations. Typical applications for the Mersen Protistor® K302666 include solar inverters, motor drives, uninterruptible power supplies (UPS), and traction converters. Its compact square body design optimizes space within power electronics cabinets while maintaining exceptional thermal and electrical performance. Mersen's Protistor® line adheres to international standards such as IEC 60269 and UL 248, ensuring high reliability in AC and DC power systems.
  • Mersen Protistor® Size 70 gR High-Speed Fuse-Link
  • Rated for 315A continuous current
  • 450VDC operational voltage (IEC 500VDC, UL 500VDC)
  • 126 kA rated breaking capacity
  • Flush metric threaded ends with striker for fault indication

Specifications

Amperage Rating
315 A
Application
Protection of inverters, motor drives, UPS systems and similar 600V or less equipments.
Brand Name
Mersen
Case
Ceramic
Connection
End Contact with Threaded Holes
Connection Type
Flush Metric Threads
Current Rating
315 A
DC Voltage Rating
500 V
Material
Silver, Sand
Mounting
Bolted
Mounting Type
DIN110 blade terminals
Series
Protistor®
Size
Size 70 gR
Size
2.91 x 1.54 x 1.81 in
Size
74 x 39 x 46 mm
Special Features
Multiple body sizes and terminals or blades combination gR Class according to IEC 60269-4 and VDE 636-23 Low I²t for improved semiconductor protection Extremely fast acting Eliminate all overloads Excellent cycling capability
Standard
IEC 60269-4 Compliance UL/CSA Recognized E76491 CCC GB 1359.4
Sub Brand
Protistor®
Type
Square Body High-Speed Fuse-Links DC Protection
Type Of Indicators
Striker
Voltage Rating
500 V
Voltage Rating
450 VDC
Wattage
46 W
Package Dimensions (L x W x H)
2.91 in x 1.54 in x 1.81 in
Package Dimensions (L x W x H)
74 mm x 39 mm x 46 mm
Package Weight (Imperial)
0.747 lb
Package Weight (Metric)
0.339 kg
Fuse Block 600VAC 600VDC Class CC 30A 1/4in Quick Connect / Solder 90 angle screw Knob Panel Mount

GPM-SRR90

Fuse Block 600VAC 600VDC Class CC 30A 1/4in Quick Connect / Solder 90 angle screw Knob Panel Mount
Fuse Block 600VAC 600VDC Class CC 30A 3-Pole Pressure Plate with Reinforced Clip

30323R

Fuse Block 600VAC 600VDC Class CC 30A 3-Pole Pressure Plate with Reinforced Clip
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 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

What is the voltage range for Protistor size 70 gR fuses?

The voltage range for these fuses is from 350 to 600 VDC.

What is the ampere range for Protistor size 70 gR fuses?

The ampere range for these fuses is from 50 A to 350 A.

What are the main applications for these fuses?

These fuses are designed for the protection of inverters, motor drives, UPS systems, and similar equipment rated at 600V or less.

Can these fuses be equipped with a trip indicator?

Yes, all fuse-links can be equipped with a low voltage trip-indicator that can operate a field mountable microswitch.

What type of semiconductor devices do these fuses protect?

These fuses are engineered to provide protection for semiconductors such as diodes, thyristors, GTO's, and IGBT devices.

What are the available mounting styles for size 70 fuse-links?

Size 70 fuse-links are available in TTF with ISO metric threaded holes and ESF with notched blade connections.

What class does the Protistor size 70 gR fuse belong to?

The Protistor size 70 gR fuse is of class gR according to IEC 60269-4 and VDE 636-23.

What is the construction material of the fuse elements?

The fuses are assembled with pure silver, die-cut elements embedded in solidified sand.

What is the pre-arcing I²t value for the 315A fuse?

The pre-arcing I²t value for the 315A fuse (catalog number D70GB45V315TF) is 24112 A²s.

What is the power dissipation at rated current for the 50A fuse?

The power dissipation at rated current for the 50A fuse (catalog number D70GB60V50TF) is 17 W.

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.