Mersen 20318R - Fuse Block 250VAC 250VDC Class R 30A 3-Pole Screw with Reinforced Clip
Mersen

20318R

Alternate Item Number: 20318R

UPC: 782001663810


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Overview

The Mersen 20318R is a 30A, 3-pole Class R fuse block designed for 250VAC/DC and 600VAC/DC applications. This UL 4248-listed and CSA-certified fuse block features high-conductivity tin-plated copper clips with spring reinforcement for reliable contact and thermal stability. The reinforced clip design ensures secure fuse retention while accommodating stranded or solid copper wires (No. 10-14 AWG) via screw connectors. The insulator is molded from glass-filled polycarbonate (GFPC), providing dielectric strength exceeding 2500V and verified safety under UL and CSA standards. Compatible with Class R fuses (e.g., A2D-R, A2K-R, TR-R for 250V), this fuse block delivers a Short-Circuit Current Rating (SCCR) of 200kA with Class R fuses, 50kA with Class K, and 10kA with Class H. Ideal for industrial control panels, motor starters, and distribution systems where high fault current protection and modular pole expansion are required. The 30A adder block system allows snap-on pole additions for flexible multi-pole configurations.
  • 30A, 3-pole Class R fuse block rated for 250VAC/DC and 600VAC/DC
  • Spring-reinforced tin-plated copper clips for secure fuse retention
  • Screw connectors for stranded/solid copper wires (No. 10-14 AWG)
  • Glass-filled polycarbonate insulator with >2500V dielectric strength
  • UL 4248-listed, CSA certified, and SCCR 200kA with Class R fuses

Specifications

AC Voltage Rating
250 V
Amperage Rating
30 A
Brand Name
Mersen
Class
Class R
Connection
Screw with Reinforced Clip
DC Voltage Rating
250 V
Material
Glass Filled Polycarbonate
Maximum Operating Temperature
80 C
Mounting
Direct Screw Mount
Number Of Poles
3-pole
Phase
3
Size
3 x 3 x 1.38 in
Size
76.2 x 76.2 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 3 in x 1.38 in
Package Dimensions (L x W x H)
76.2 mm x 76.2 mm x 35.052 mm
Package Weight (Imperial)
0.340 lb
Package Weight (Metric)
0.154 kg
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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.