Mersen 20357R Fuse Block 250VAC 250VDC Class R 30A 2-Pole Copper Box
Alternate Item Number: 20357R
UPC: 782001754167
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Contact for Pricing
Call +1 (262) 252-1600 (toll-free 877-268-3700) or email [email protected] for pricing and availability.
Overview
- Rated for 250VAC/250VDC and 600VAC/600VDC with Class H, K, and R fuses
- 30A 2-pole design with copper box connectors and spring-reinforced tin-plated copper clips
- Dielectric strength verified in excess of 2500V; UL 4248 certified
- Supports stranded/solid copper or aluminum wire (#2-14 AWG for 30A)
- SCCR ratings: 10kA (Class H), 50kA (Class K), 200kA (Class R)
Specifications
AC Voltage Rating | 250 V |
Amperage Rating | 30 A |
Brand Name | Mersen |
Class | Class R |
Connection | Copper Box |
Connection Type | Screw, Pressure Plate, Box, Stud |
Current Rating | 30A |
DC Voltage Rating | 250 V |
Material | Glass Filled Polycarbonate |
Material | Copper, Glass-Filled Polycarbonate (GFPC), Phenolic |
Maximum Operating Temperature | 80 C |
Maximum Operating Temperature | 80 °C |
Mounting | Direct Screw Mount |
Number Of Poles | 2-pole |
Phase | 2 |
Poles | 2 |
Size | 3 x 2.03 x 1.38 in |
Size | 76.2 x 51.562 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 2.03 in x 1.38 in |
Package Dimensions (L x W x H) | 76.2 mm x 51.562 mm x 35.052 mm |
Package Weight (Imperial) | 0.240 lb |
Package Weight (Metric) | 0.109 kg |
LFH25030-2C
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.
Frequently Asked Questions
What voltage and amperage ratings are available for these fuse blocks?
These fuse blocks are rated for 250VAC/DC and 600VAC/DC, with amperage ratings of 30A, 60A, 100A, 200A, 400A, and 600A.
What wire range is supported by the 30A GFPC insulator box connectors for Al/Cu wire?
The 30A GFPC insulator box connectors for Al/Cu wire support a wire range of #2-14.
What wire range is supported by the 100A box connectors for Cu wire?
The 100A box connectors for Cu wire support a wire range of 2/0-#12.
What wire range is supported by the 400A box side-clip connectors for Al/Cu wire?
The 400A box side-clip connectors for Al/Cu wire support a range of 1000-250kcmil.
What are the SCCR ratings for these fuse blocks with different fuse classes?
SCCR ratings are 10kA with class H fuses, 50kA with class K fuses, and 200kA with class R fuses.
What are the fuse clip materials and types available?
Fuse clips are high conductivity tin-plated copper, with options for spring-reinforced or non-spring-reinforced clips in 30A and 60A sizes.
What is the recommended torque for 200A box connectors (Cu) with side-clip?
The recommended torque for 200A box connectors (Cu) with side-clip is 275 in-lbs.
What are the insulation materials used in these fuse blocks?
Insulators are either molded glass-filled polycarbonate (GFPC) or phenolic, with dielectric strength exceeding 2500V.
What is the recommended torque for 30A screw connectors?
The recommended torque for 30A screw connectors is 20 in-lbs.
What is the recommended mounting screw size for 100A fuse blocks?
The recommended mounting screw size for all 100A fuse blocks is 1/4" (.250" dia.).
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.