Authorized Mersen Distributor
Mersen OTM25 - Fuse OTM - Midget - Fast-Acting 250VAC 25A Ferrule Amp-Trap®
More images

Mersen OTM25 Fuse OTM - Midget - Fast-Acting 250VAC 25A Ferrule Amp-Trap®

Alternate Item Number: OTM25

UPC: 782001705145


Documents & Media
Technical DrawingLine DrawingSpecification Sheet

Contact for Pricing

Minimum Qty: 10

Multiplier: 10

*Contact for lower quantities*

Call +1 (262) 252-1600 (toll-free 877-268-3700) or email [email protected] for pricing and availability.

Overview

The Mersen OTM25 is a one-time fast-acting midget fuse designed for cost-effective protection in 250VAC general purpose applications where time-delay is not required. This 25A ferrule-type fuse provides supplemental protection for circuits up to 250VAC and 10kA fault current, making it ideal for lighting, heating, and control circuits. With a compact 1 1/2" x 13/32" (10mm x 38mm) footprint, the OTM25 fits space-constrained installations without compromising performance. Compatible with Mersen UltraSafe™ fuse holders, it offers a low-cost solution for general purpose circuit protection. The fuse is constructed with a high-purity silver element for consistent performance and long service life, ensuring reliable operation in demanding environments. Its fast-acting response time minimizes damage to sensitive equipment during fault conditions, while the ferrule design ensures secure electrical contact and reduces the risk of loose connections. The OTM25 is UL Listed to standard 248-14 (File E33925) and CSA Certified to Standard C22.2 No. 248.14, meeting rigorous safety and performance requirements. Note: Not suitable for branch circuit protection. Available in current ratings from 1A to 30A, the OTM25 provides flexibility for a wide range of applications, including industrial control panels, motor circuits, and appliance protection.
  • 25A fast-acting midget fuse for 250VAC general purpose circuits
  • 10kA interrupting rating for supplemental protection
  • Compact 1 1/2" x 13/32" (10mm x 38mm) ferrule-type design
  • Compatible with Mersen UltraSafe™ fuse holders
  • UL Listed to standard 248-14 and CSA Certified to C22.2 No. 248.14

Specifications

AC Voltage Rating
250 V
Amperage Rating
25 A
Application
Supplemental protection of circuits up to 250VAC and 10kA
Body Material
Paper
Brand Name
Mersen
Class
Midget
Connection
Ferrule
Connection Material
Tin-Plated Copper
Fuse Class
Midget
Interrupt Rating
10 kA
Mounting
Clip
Size
1.5 x 0.41 in
Size
38.1 x 10.312 mm
Special Features
Low cost and fully rated for economy without compromise Can be used with UltraSafe™ fuse holders 1 1/2" x 13/32" (10 mm x 38 mm) dimensions
Standard
UL Listed to standard 248-14, File E33925 CSA Certified to Standard C22.2 No. 248.14
Sub Brand
Amp-Trap®
Type
Midget Fuses
Voltage Rating
250 VAC
Package Dimensions (L x W x H)
1.5 in x 0.41 in x 0.41 in
Package Dimensions (L x W x H)
38.1 mm x 10.312 mm x 10.312 mm
Package Weight (Imperial)
0.012 lb
Package Weight (Metric)
0.005 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 Block 600VAC 600VDC Class CC 30A 3-Pole Pressure Plate with Reinforced Clip

30323R

Fuse Block 600VAC 600VDC Class CC 30A 3-Pole Pressure Plate with Reinforced Clip
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 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

What is the interrupting rating of the OTM25?

The OTM25 has a 10kA interrupting rating, providing supplemental protection for circuits up to 250VAC and 10kA fault current.

What are the dimensions of the OTM25 fuse?

The OTM25 measures 1 1/2" x 13/32" (10mm x 38mm), making it suitable for space-constrained installations.

Is the OTM25 compatible with fuse holders?

Yes, the OTM25 is compatible with Mersen UltraSafe™ fuse holders for secure installation and replacement.

What applications is the OTM25 suitable for?

The OTM25 is designed for general purpose lighting, heating, and control circuits where time-delay protection is not required.

What is the voltage rating of the OTM25?

The OTM25 has a voltage rating of 250VAC, suitable for general purpose AC circuits.

Can the OTM25 be used for branch circuit protection?

No, the OTM25 is not suitable for branch circuit protection; it is designed for supplemental protection only.

What current ratings are available for the OTM series?

The OTM series is available in current ratings from 1A to 30A, including the OTM25 at 25A.

What standards does the OTM25 meet?

The OTM25 is UL Listed to standard 248-14 (File E33925) and CSA Certified to Standard C22.2 No. 248.14.

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.