Mersen OTN45 - OTN Fuse OT - Class K5 - Fast-Acting 250VAC 45A Ferrule Amp-Trap®
Mersen

OTN45

Alternate Item Number: OTN45

UPC: 068938831066


Documents & Media
Line Drawing

Contact for Pricing

Overview

The Mersen OTN45 (SKU: OTN45) is a Class K-5, fast-acting ferrule fuse designed for reliable overcurrent protection in feeder and branch circuits. Rated for 250VAC and 45A, this one-time fuse offers a 50kA interrupting rating, ensuring safety for non-motor loads such as lighting and resistive heating applications. It meets UL 248-9 and CSA C22.2 No. 248.9 standards, providing compliance for industrial and commercial installations. The ferrule design ensures secure connections, and the clear imprint label facilitates easy identification and replacement. This versatile fuse is compatible with standard fuse blocks and box connectors, offering a low-cost, high-value protection solution for residential, small commercial, and industrial settings. Its fast-acting nature makes it suitable for applications requiring non-time-delay protection. The OTN45 is part of Mersen's OTN series, which provides low-cost protection for circuits serving non-inductive loads up to 50,000 amperes. The fuse is designed for use in feeders, branch circuits, and resistive heating applications, with a current rating range of 15 to 60A for 250VAC systems.
  • Class K-5 fast-acting ferrule fuse for non-motor loads
  • Rated 45A at 250VAC with 50kA interrupting rating
  • UL 248-9 and CSA C22.2 No. 248.9 compliant
  • Ferrule design ensures secure, reliable connections
  • Compatible with standard fuse blocks and box connectors

Specifications

AC Voltage Rating
250 V
Amperage Rating
45 A
Application
Feeders Branch circuits Resistive heating Residential and small commercial installations
Body Material
Paper
Brand Name
Mersen
Class
Class K5
Connection
Ferrule
Connection Material
Copper
Interrupt Rating
10 kA
Mounting
Clip
Size
3 x 0.81 in
Size
76.2 x 20.574 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)
3 in x 0.81 in x 0.81 in
Package Dimensions (L x W x H)
76.2 mm x 20.574 mm x 20.574 mm
Package Weight (Imperial)
0.090 lb
Package Weight (Metric)
0.041 kg
Fuse Block 600VAC 600VDC Class CC 30A 1/4in Quick Connect / Solder 90 angle screw Knob Panel Mount

GPM-SRR90

Fuse Block 600VAC 600VDC Class CC 30A 1/4in Quick Connect / Solder 90 angle screw Knob Panel Mount
Fuse Holder UltraSafe™ 800VAC 1000VDC UL Fuse size 14x51 1-Pole Visual Indicator Microswitch Pressure Plate IP20

C331156

Fuse Holder UltraSafe™ 800VAC 1000VDC UL Fuse size 14x51 1-Pole Visual Indicator Microswitch Pressure Plate IP20
Fuse Block 1500VAC 1500VDC 400A 1-Pole Stud M8

1SCM8

Fuse Block 1500VAC 1500VDC 400A 1-Pole Stud M8
Fuse Holder Modulostar® Size 10x38 IEC 690VAC 690VDC 3-Pole IP20

E1062696

Fuse Holder Modulostar® Size 10x38 IEC 690VAC 690VDC 3-Pole IP20
POWR-JAW clamps improve the contact between fuse and clip. The unnecessary heat from poor contact due to the loss of spring force in the clips can cause nuisance fuse opening and premature aging of surrounding components. High temperature phenolic resin knob designed for the most severe environments 7 sizes to provide effective coverage. Simple design makes installation easy.

LCC5

POWR-JAW clamps improve the contact between fuse and clip. The unnecessary heat from poor contact due to the loss of spring force in the clips can cause nuisance fuse opening and premature aging of surrounding components. High temperature phenolic resin knob designed for the most severe environments 7 sizes to provide effective coverage. Simple design makes installation easy.
9F61 Size B Clips 1.6in

9F61BWW460

9F61 Size B Clips 1.6in

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.