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Mersen 20356 - Fuse Block 250VAC 250VDC Class H/K 30A 1-Pole Copper Box
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Mersen 20356 Fuse Block 250VAC 250VDC Class H/K 30A 1-Pole Copper Box

Alternate Item Number: 20356

UPC: 782001756994


Documents & Media
Specification 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 SKU 20356 is a single-pole fuse block engineered for Class H, K, and R fuse applications, rated for 250VAC and 250VDC at 30 Amperes. This model features copper box connectors and copper fuse clips, ensuring compatibility exclusively with copper wires. The design matches the coefficient of thermal expansion of copper wire, delivering superior heat cycling performance and meeting OEM specifications that prohibit aluminum conductors. The insulator is constructed from Glass-Filled Polycarbonate (GFPC), providing robust dielectric strength. The wire range for this fuse block is #4 to #14 AWG copper wire, with a recommended connector torque of 35 in-lbs. This fuse block is part of Mersen's Class H, K, and R fuse block line, designed for reliable overcurrent protection in copper wiring systems where these fuse classes are specified. The 1-pole configuration is ideal for single-circuit protection needs in industrial, commercial, and utility applications.
  • Rated for 250VAC and 250VDC at 30 Amperes
  • Compatible with Class H, K, and R fuses
  • Copper box connectors and clips for copper wire only (#4 to #14 AWG)
  • Glass-Filled Polycarbonate (GFPC) insulator for dielectric strength
  • Recommended torque: 35 in-lbs

Specifications

AC Voltage Rating
250 V
Amperage Rating
30 A
Brand Name
Mersen
Class
Class H/K
Connection
Copper Box
Connection Type
Screw, pressure plate, box, or stud connectors
Current Rating
30A
DC Voltage Rating
250 V
Material
Copper, Glass-filled Polycarbonate (GFPC) or Phenolic
Material
Glass Filled Polycarbonate
Maximum Operating Temperature
80 °C
Maximum Operating Temperature
80 C
Mounting
Direct Screw Mount
Number Of Poles
1
Phase
1
Poles
1-pole
Series
Class H/K
Size
3 x 1.25 x 1.38 in
Size
76.2 x 31.75 x 35.052 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)
3 in x 1.25 in x 1.38 in
Package Dimensions (L x W x H)
76.2 mm x 31.75 mm x 35.052 mm
Package Weight (Imperial)
0.140 lb
Package Weight (Metric)
0.064 kg
Fuse Block 250VAC 250VDC Class R 30A 1-Pole Copper Box

20356R

Fuse Block 250VAC 250VDC Class R 30A 1-Pole Copper Box
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
Fuse Block 250VAC 250VDC Class H/K 30A 1-Pole Pressure Plate with Reinforced Clip

20326

Fuse Block 250VAC 250VDC Class H/K 30A 1-Pole Pressure Plate with Reinforced Clip
Fuse Block 600VAC 600VDC Class J 60A 3-Pole Copper Box

60658J

Fuse Block 600VAC 600VDC Class J 60A 3-Pole Copper Box
Fuse Block 600VAC 600VDC Class H/K 30A 1-Pole Pressure Plate

60321

Fuse Block 600VAC 600VDC Class H/K 30A 1-Pole Pressure Plate
Fuse Block 600VAC 600VDC Class R 100A 1-Pole Box with Reinforced Clip

61036R

Fuse Block 600VAC 600VDC Class R 100A 1-Pole Box with Reinforced Clip
Fuse Block 600VAC 600VDC Class R 30A 3-Pole Copper Box

60358R

Fuse Block 600VAC 600VDC Class R 30A 3-Pole Copper Box

Frequently Asked Questions

What voltage and amperage ratings are available for these fuse blocks?

The fuse blocks are available in 250VAC/DC and 600VAC/DC ratings, with amperage options of 30A, 60A, 100A, 200A, 400A, and 600A.

What are the SCCR ratings for different fuse classes?

SCCR ratings are 10kA with class H fuses, 50kA with class K fuses, and 200kA with class R fuses.

What types of wire can be used with the connectors?

Connectors can accommodate stranded or solid copper or aluminum wire, with specific wire ranges varying by amperage and connector type.

What are the insulator materials and their dielectric strength?

Insulators are either molded glass-filled polycarbonate (GFPC) or phenolic, with verified dielectric strength exceeding 2500V.

Can I add poles to the 30, 60, and 100A fuse blocks?

Yes, a unique adder block can be snapped onto 1-, 2-, or 3-pole blocks to form multi-pole segmented blocks of any desired pole count.

What are the fuse clips made of and what types are available?

All fuse clips are made of high conductivity tin-plated copper. Spring reinforced or non-spring reinforced clips are available for 30A and 60A, while 100A and above are spring reinforced.

What are the recommended mounting screws for 30A and 60A fuse blocks?

The recommended mounting screws for all 30A and 60A fuse blocks are #10 (.190" dia.).

What are the recommended mounting screws for 100A and 200A fuse blocks?

For 100A blocks, use 1/4" (.250" dia.) screws. For 200A, 1-pole blocks use #10 (.190” dia.), and for 200A, 3-pole blocks use 5/16” (.313” dia.).

What are the recommended mounting screws for 400A and 600A fuse blocks?

The recommended mounting screws for all 400A and 600A fuse blocks are 5/16" (.313" dia.).

Which fuse classes are compatible with the 250V and 600V blocks?

250V blocks are compatible with Class H, K, and R fuses. 600V blocks are also compatible with Class H, K, and R fuses.

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.