Mersen A550T1/2E-STI - Mersen PT fuses are current-limiting fuses with high interrupting rating, used for the primary winding protection of potential transformer. They are small dimension ferrule type fuses and mount in standard clips. Current ratings are from 0.25A to 5A. 5500 Volts 0.5 Amps A550T-S series.
Mersen

A550T1/2E-STI

Alternate Item Number: 782001375898

UPC: 782001375898

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Overview

Protect your critical potential transformer (PT) installations with the Mersen A550T1/2E-STI, a current-limiting fuse engineered for superior primary winding protection. This compact, ferrule-type fuse, part of the A550T-S series, offers exceptional reliability and safety in demanding industrial environments. Rated for 5500V and a precise 0.5A, the A550T1/2E-STI is specifically designed to safeguard the sensitive primary windings of potential transformers from damaging overcurrents and short circuits. Its current-limiting capabilities ensure rapid interruption of fault currents, minimizing stress on connected equipment and preventing catastrophic failures. The Mersen A550T1/2E-STI features a small dimension ferrule design for straightforward installation into standard fuse clips, making it ideal for space-constrained electrical panels and control cabinets. This fuse is a vital element in maintaining the operational integrity and longevity of power monitoring and control systems. With a high interrupting rating, it safely and effectively manages severe fault conditions, preventing widespread system disruption. Potential transformers are essential for accurate voltage measurement and metering in power systems; protecting their primary windings ensures the accuracy and reliability of these measurements, impacting grid stability, load management, and protective relaying. The Mersen A550T1/2E-STI provides the specialized protection required for these sensitive devices, adhering to stringent industry standards. Key features include superior primary winding protection for PTs, a 5500V rating for medium-voltage applications, a precise 0.5A rating, current-limiting technology, compact ferrule design for easy installation, and a high interrupting rating. Manufactured by Mersen, a trusted leader in electrical protection solutions, the A550T1/2E-STI offers consistent performance and long-term durability. Invest in the reliability and safety of your electrical infrastructure with this indispensable component for protecting valuable potential transformers.
  • Specifically designed for potential transformer (PT) primary winding protection.
  • Current-limiting fuse with a high interrupting rating.
  • Rated for 5500 Volts and 0.5 Amps.
  • Compact, small dimension ferrule type for mounting in standard clips.
  • Part of the robust Mersen A550T-S series.

Specifications

Brand Name
Ferraz Shawmut
Package Dimensions (L x W x H)
7.4 IN x 1.59 IN x 1.59 IN
Package Dimensions (L x W x H)
18.796 cm x 4.0386 cm x 4.0386 cm
Package Weight (Imperial)
0.500 L
Package Weight (Metric)
0.227 kg
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Fuse Holder UltraSafe™ 800VAC 1000VDC UL Fuse size 14x51 1-Pole Visual Indicator Microswitch Pressure Plate IP20

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Fuse Block 1500VAC 1500VDC 400A 1-Pole Stud M8

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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.