Mersen 21038 - Fuse Block 250VAC 250VDC Class H/K 100A 3-Pole Copper Box
Mersen

21038

Alternate Item Number: 21038

UPC: 782001664435


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Overview

The Mersen 21038 is a 3-pole, 100A fuse block designed for Class H, K, and R fuses at 250VAC/DC. Engineered with high-conductivity tin-plated copper clips and copper box connectors, it ensures reliable heat cycling and meets OEM "no aluminum" specifications. The molded glass-filled polycarbonate (GFPC) insulator provides dielectric strength exceeding 2500V, ensuring safety in high-voltage applications. Compatible with stranded or solid copper wire (2/0 to #12 AWG), this fuse block features spring-reinforced clips for 100A ratings, delivering superior contact stability under load. The unique adder block design allows easy conversion to multipole segmented blocks by snapping additional poles onto 1-, 2-, or 3-pole units. With UL 4248 compliance and CSA certification, the 21038 is ideal for industrial power distribution, motor control centers, and panelboard applications where Class H, K, or R fuses are required. Recommended mounting screws are 1/4" (0.250" dia.) for secure installation.
  • 100A, 3-pole fuse block for Class H, K, and R fuses at 250VAC/DC
  • High-conductivity tin-plated copper clips and copper box connectors for copper wire only (2/0 to #12 AWG)
  • Molded GFPC insulator with dielectric strength >2500V for safety
  • Spring-reinforced clips for 100A ratings for enhanced contact stability
  • Adder block design enables multipole segmented configurations

Specifications

AC Voltage Rating
250 V
Amperage Rating
100 A
Brand Name
Mersen
Class
Class H/K
Connection
Copper Box
Connection Type
Screw, Pressure Plate, Box, Stud
Current Rating
100A
DC Voltage Rating
250 V
Material
Glass Filled Polycarbonate
Material
Copper Box, Glass-Filled Polycarbonate (GFPC) or Phenolic
Maximum Operating Temperature
80 C
Mounting
Direct Screw Mount
Number Of Poles
3-pole
Phase
3
Poles
3
Series
Class H/K
Size
8.33 x 4.72 x 2.28 in
Size
211.582 x 119.888 x 57.912 mm
Standard
All fuse blocks meet the requirements of UL 4248 UL listed, guide IZLT, File E52283 UL recognized component guide IZLT2, file E52283 CSA certified class 6225, File 32169
Type
UL/CSA Fuse Bases
Voltage Rating
250 VAC
Package Dimensions (L x W x H)
8.33 in x 4.72 in x 2.28 in
Package Dimensions (L x W x H)
211.582 mm x 119.888 mm x 57.912 mm
Package Weight (Imperial)
1.820 lb
Package Weight (Metric)
0.826 kg
Fuse Block 250VAC 250VDC Class H/K 100A 2-Pole Box with Reinforced Clip

21007

Fuse Block 250VAC 250VDC Class H/K 100A 2-Pole Box with Reinforced Clip
The new Littelfuse Class H blocks offer many advantages over previous generations that are noted in the features and benefits section. Class H and Class R fuse blocks are dimensionally the same, but Class R blocks incorporate a rejection feature, which only allows Class R fuses to be inserted.

LFH25030-1S

The new Littelfuse Class H blocks offer many advantages over previous generations that are noted in the features and benefits section. Class H and Class R fuse blocks are dimensionally the same, but Class R blocks incorporate a rejection feature, which only allows Class R fuses to be inserted.
DR4/8 SF DIN2

1SNA110368R1200

DR4/8 SF DIN2

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.