Mersen A4BY2500-TI Fuse A4BY - Class L - Time-Delay 600VAC 300VDC 2500A Blade TI Indicator Amp-Trap®
Alternate Item Number: A4BY2500-TI
UPC: 782001939618
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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
- Class L, Time-Delay Fuse
- 600VAC / 300VDC Voltage Rating
- 2500A Ampere Rating
- 100% Rated Device for Continuous Current
- 4-Second Minimum Time Delay at 500% Rating
- Blade Indicator for Status
- Ideal for Service Entrance, Feeder Circuits, and Circuit Breaker Protection
- Facilitates Coordination with Ground Fault Relays
- Manufacturer: Mersen
- SKU: A4BY2500-TI
Specifications
AC Voltage Rating | 600 V |
Amperage Rating | 2500 A |
Application | Mains Feeders Circuit Breakers Load centers Panelboards Switchboards Metering Centers |
Body Material | GMG |
Brand Name | Mersen |
Class | Class L |
Connection | Blade |
Connection Material | Silver-Plated Copper |
Current Rating | 2500 A |
DC Voltage Rating | 300 V |
Fuse Class | L |
Interrupt Rating | 200 kA |
Mounting | Bolted |
Series | Amp-Trap A4BY |
Size | 10.75 x 4.5 in |
Size | 273.05 x 114.3 mm |
Special Features | Unique dimensions prevent replacement by other fuse classes Blade-stamped catalog numbers for permanent identification Glass melamine body and plated terminals provide superior reliability in harsh environments |
Standard | Mersen Self-Certification, UL Listed to Standard 248-10, File E2137 CSA Certified to Standard C22.2, No. 248.10 IEC 269-2-1 DC Tested to UL 248 limits (Mersen Self-Certified) |
Sub Brand | Amp-Trap® |
Type | Class L |
Type Of Indicators | TI Indicator |
Voltage Rating | 600 VAC |
Package Dimensions (L x W x H) | 10.75 in x 4.5 in x 4.5 in |
Package Dimensions (L x W x H) | 273.05 mm x 114.3 mm x 114.3 mm |
Package Weight (Imperial) | 15.300 lb |
Package Weight (Metric) | 6.940 kg |

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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.Frequently Asked Questions
What are the voltage and current ratings for A4BY fuses?
A4BY fuses are rated for 600VAC and 300VDC. Amperage ratings range from 200 to 6000A for AC and 200 to 2500A for DC.
What is the interrupting rating (I.R.) for A4BY fuses?
The interrupting rating is 200kA I.R. AC and 100kA I.R. DC.
What is the time delay characteristic of A4BY fuses?
A4BY fuses have a 4-second minimum time delay at 500% rating, allowing them to pass normal current surges.
Are A4BY fuses UL listed and CSA certified?
Yes, A4BY fuses are UL listed to standard 248-10 and CSA certified to standard C22.2 No. 248.10.
What applications are A4BY fuses suitable for?
A4BY fuses are suitable for mains, feeders, circuit breakers, load centers, panelboards, switchboards, and metering centers.
What does the '-TI' suffix indicate on A4BY catalog numbers?
The '-TI' suffix indicates an optional blown fuse trigger indicator. Consult the factory for availability.
Can A4BY fuses be replaced by other fuse classes?
No, unique dimensions prevent replacement by other fuse classes, ensuring proper application.
What are the body and terminal materials of A4BY fuses?
A4BY fuses have a glass melamine body and plated terminals for superior reliability in harsh environments.
What is the purpose of the 4-second time delay at 500% rating?
The 4-second time delay allows the A4BY fuse to pass normal current surges and coordinate with ground fault relays.
What is the maximum continuous current rating for A4BY fuses?
The A4BY is a 100% rated device and may be applied at continuous currents up to its ampere rating.
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.









