Mersen OT350 - Fuse OT - Class K5 - Fast-Acting 250VAC 250VDC 350A Blade Amp-Trap®
Mersen

OT350

Alternate Item Number: OT350

UPC: 782001700461


Documents & Media
Technical DrawingLine Drawing

Contact for Pricing

Overview

The Mersen OT350 (SKU: OT350) is a Class K-5 fast-acting fuse designed for reliable protection of feeder and branch circuits. It is specifically suited for non-motor loads such as lighting and heating. This fuse operates at 250VAC/DC and has a current rating of 350A. It offers an interrupting rating of 50kA AC and 20kA DC, ensuring safety against short-circuit currents. The OT350 is UL Listed to Standard 248-9 (File E2137) and CSA Certified to Standard C22.2 No. 248.9, and is self-certified for DC applications per UL248. It is a versatile and cost-effective protection solution for residential, small commercial, and industrial installations. Note that this is not a rejection-type fuse, so replacement fuses must match or exceed the original interrupting ratings. Mersen offers this fuse series in ampere ratings from 1A to 600A with various voltage options including 250VAC/DC and 600VAC/300VDC. The fuse features an easy-to-read imprint label for quick identification and replacement, minimizing downtime. UNSPSC Code: 39121627. Country of Origin: DE.
  • Class K-5 Fast-Acting Fuse
  • 350 Ampere Rating
  • 250VAC/DC Voltage Rating
  • 50kA AC / 20kA DC Interrupting Rating
  • UL Listed to Standard 248-9, CSA Certified to Standard C22.2 No. 248.9

Specifications

AC Voltage Rating
250 V
Amperage Rating
350 A
Application
Feeders Branch circuits Resistive heating Residential and small commercial installations
Body Material
PolyTube
Brand Name
Mersen
Class
Class K5
Connection
Blade
Connection Material
Tin-Plated Copper
DC Voltage Rating
250 V
Interrupt Rating
50 kA
Mounting
Clip
Size
8.63 x 2.06 in
Size
219.202 x 52.375 mm
Special Features
Easy to read imprint label for quick recognition and replacement Low cost for high protection value
Standard
UL Listed to Standard 248-9 File E2137 CSA Certified to Standard C22.2 No. 248.9 (The Canadian Electrical Code requires these fuses in ratings 15 through 60A to be of the low melting point design use OTN 15-60.) Self-certified for DC per UL248
Sub Brand
Amp-Trap®
Type
Class K5
Voltage Rating
250 VAC
Package Dimensions (L x W x H)
8.63 in x 2.06 in x 2.06 in
Package Dimensions (L x W x H)
219.202 mm x 52.375 mm x 52.375 mm
Package Weight (Imperial)
1.450 lb
Package Weight (Metric)
0.658 kg

Similar Products

OT35


Amperage Rating: 35 A

Connection: Ferrule

Size: 3 x 0.81 in

OT300


Amperage Rating: 300 A

Voltage Rating: 250VAC 250VDC

Current Rating: 300A

OT150


Amperage Rating: 150 A

Size: 7.13 x 1.56 in

OT250


Amperage Rating: 250 A

Voltage Rating: 250VAC 250VDC

Current Rating: 250A

OT3


Amperage Rating: 3 A

Connection: Ferrule

Size: 2 x 0.56 in

OT30


Amperage Rating: 30 A

Connection: Ferrule

Size: 2 x 0.56 in

You May Also Be Interested In

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.