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Mersen A6D125/400R - Reducer Fuse A6D-R - Class RK1 - Time-Delay 600VAC 600VDC 125A Blade SmartSpot® Amp-Trap 2000®
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Mersen A6D125/400R Reducer Fuse A6D-R - Class RK1 - Time-Delay 600VAC 600VDC 125A Blade SmartSpot® Amp-Trap…

Alternate Item Number: A6D125/400R

UPC: 782001489519


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Technical DrawingLine DrawingSpecification Sheet

Contact for Pricing

Call +1 (262) 252-1600 (toll-free 877-268-3700) or email [email protected] for pricing and availability.

Overview

The Mersen A6D125/400R Reducer Fuse is a Class RK1, time-delay fuse designed for 600VAC and 600VDC systems, rated at 125A. Part of the Amp-Trap 2000® series, it provides a permanent solution for reducing current ratings in electrical systems without temporary accessories. The Class RK1 rating delivers high interrupting capacity, protecting equipment from overcurrents and short circuits. Unlike standard fuses, the A6D125/400R offers a larger body design for enhanced durability in demanding industrial environments. It is engineered for applications requiring precise current reduction while maintaining full protective capabilities. Commonly used in heavy-duty equipment, traction rectifiers, and electrochemical systems where sustained overloads and high fault currents are present. The fuse’s low I²t minimizes damage to protected components during short circuits, and its controlled arc voltage reduces stress on circuit components during operation.
  • Class RK1 time-delay fuse for 600VAC/VDC systems
  • 125A current rating with permanent current reduction capability
  • SmartSpot® indicator for quick blown-fuse identification
  • High interrupting capacity for overcurrent and short-circuit protection
  • Low I²t minimizes component damage during faults

Specifications

AC Voltage Rating
600 V
Amperage Rating
125 A
Application
Motors Safety switches Transformers Branch circuit protection Disconnects Control panels All general-purpose circuits
Body Material
PolyTube
Brand Name
Mersen
Class
Class RK1
Connection
Blade
Connection Material
Tin-Plated Copper
Current Rating
125 A
Interrupt Rating
200 kA
Mounting
Clip
Series
Amp-Trap 2000
Size
11.63 x 2.56 in
Size
295.402 x 65.024 mm
Size
11.63 x 2.56;295.402 x 65.024 in;mm
Special Features
Replaces traditional temporary-use only Fuse Reducer accessories Time-delay for motor starting and transformer inrush currents without nuisance opening 600VAC & 600VDC dual rated 300kA interrupting rating - self-certified, UL witnessed tests Extremely current-limiting for low peak let-thru current Recommended for Arc Flash energy reduction Easy 2-to-1 selectivity for prevention of nuisance shut downs and “black outs” Rejection-style design prevents replacement errors (when used with recommended fuse blocks) High-visibility orange label gives instant brand recognition Reduced inventory by taking the place of lower-rated Class RK1 fuses and associated Fuse Reducer accessories Metal-embossed date and catalog number for easier traceability and lasting identification Fiberglass body provides dimensional stability in harsh industrial settings
Standard
UL Special Purpose Listed to 248-12 DC listed to UL standard 248 CSA certified to standard C22.2 No. 248.12
Sub Brand
Amp-Trap 2000®
Type
Class RK1
Type Of Indicators
SmartSpot®
Voltage Rating
600VAC/600VDC
Package Dimensions (L x W x H)
11.63 in x 2.56 in x 2.56 in
Package Dimensions (L x W x H)
295.402 mm x 65.024 mm x 65.024 mm
Package Weight (Imperial)
3.400 lb
Package Weight (Metric)
1.542 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

What are the voltage ratings for the A6D-R fuses?

The A6D-R fuses are dual rated for 600VAC and 600VDC.

What are the voltage ratings for the A2D-R fuses?

The A2D-R fuses are rated for 250VAC/DC.

What is the primary purpose of A2D-R and A6D-R Reducer Fuses?

These fuses provide a safe, permanent solution for decreasing current ratings without needing a separate Fuse Reducer accessory.

What is the interrupting rating for the A6D-R fuses?

The A6D-R fuses have a 200kA I.R. AC and 100kA I.R. DC rating, self-certified for 300kA I.R. with UL witnessed tests.

What is the interrupting rating for the A2D-R fuses?

The A2D-R fuses have a 200kA I.R. AC and 100kA I.R. DC rating.

What type of protection do these fuses offer?

They offer time-delay protection for motor starting and transformer inrush currents, preventing nuisance openings.

What information is embossed on the fuse body?

The fuse body has metal-embossed date and catalog number for easier traceability and lasting identification.

What is the purpose of the time-delay feature?

The time-delay feature is for motor starting and transformer inrush currents, preventing nuisance opening.

What applications are these reducer fuses suitable for?

They are suitable for motors, safety switches, transformers, branch circuit protection, disconnects, control panels, and general-purpose circuits.

Are these fuses compatible with standard fuse blocks?

A rejection-style design prevents replacement errors when used with recommended fuse blocks.

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.