Mersen U70505 Fuse Block 750VAC 750VDC 50A Adder Box
Alternate Item Number: U70505
UPC: 782001323578
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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
- 50A current rating for 14x51mm IEC cylindrical fuses
- Rated 750VAC and 750VDC with dielectric strength >2500V
- Adder-block design enables multi-pole segmented configurations
- UL Recognized (IZLT2, File E52283) and CSA Certified (Class 6225, File 32169)
Specifications
AC Voltage Rating | 750 V |
Amperage Rating | 50 A |
Application | All circuits up to 750 volts using semiconductor fuses for protection of small inverters, UPS systems, motor drives, etc. |
Brand Name | Mersen |
Class | IEC Cylindrical 14x51mm |
Connection | Box |
DC Voltage Rating | 750 V |
Material | Thermoplastic |
Maximum Operating Temperature | 80 C |
Maximum Operating Temperature | 80 °C |
Mounting | Screw Mount or DIN Rail |
Number of Poles | 1 |
Phase | 1 |
Size | 3 x 0.97 x 1.37 in |
Size | 76.2 x 24.638 x 34.798 mm |
Special Features | Thermoplastic bases DIN-rail (U710) or Screw Mount Adder block design |
Standard | UL Recognized component guide IZLT2, File E52283 CSA Certified class 6225, File 32169 |
Type | Semiconductor & Special Purpose Fuse Bases & Accessories |
Voltage Rating | 750 VAC |
Package Dimensions (L x W x H) | 3 in x 0.97 in x 1.37 in |
Package Dimensions (L x W x H) | 76.2 mm x 24.638 mm x 34.798 mm |
Package Weight (Imperial) | 0.100 lb |
Package Weight (Metric) | 0.045 kg |

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Fuse Block 600VAC 600VDC 30A 1/4in Quick Connect / Solder 90 angle 1/4 Turn Bayonet Knob Panel MountFrequently Asked Questions
What fuse sizes are compatible with the U70505 fuse holder?
The U70505 fuse holder is designed for 14 x 51 mm fuses.
What is the ampacity rating for the U70505 fuse holder?
The U70505 fuse holder has an ampacity rating of 50A.
What type of connectors does the U70505 fuse holder offer?
The U70505 fuse holder features box connectors suitable for Al/Cu wires.
What is the wire range for the box connectors on the U70505?
The box connectors on the U70505 can accommodate wire sizes from #2 to #14.
What is the recommended connector torque for the U70505?
The recommended connector torque for the U70505 is 35 in-Lb.
What is the voltage rating for Mersen semiconductor fuse holders?
Mersen semiconductor fuse holders, including the U70505, are rated for 750 volts.
What is the SCCR for the U70505 fuse holder?
The SCCR for the U70505 is 200kA, dependent on the fuse's I.R.
What are the dielectric strength capabilities of these fuse holders?
All versions have verified dielectric strengths in excess of 2500V.
What type of base material is used for the U70505 fuse holder?
The U70505 fuse holder features thermoplastic bases.
What are the applications for the U70505 fuse holder?
The U70505 is used in circuits up to 750 volts for protection of small inverters, UPS systems, and motor drives.
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.



