Description
Overview
The Eaton Bussmann 250MT is a single barrel, high-speed BS88 Type semiconductor protection fuse rated at 250 A and 690 V AC (450 V DC), designed specifically to protect semiconductor devices such as thyristors, diodes, IGBTs, and SCRs in high-power electronic systems. Conforming to BS88 Part 4 and IEC 60269-4, this Class aR fuse provides exceptionally fast let-through current limiting, minimizing I²t energy and preventing catastrophic damage to vulnerable power electronics. It carries CE marking, RoHS compliance, IEC rating, and UL recognition, making it suitable for both Indian and export-oriented industrial panel applications.
Key Features
- High-Speed Current Limiting — Class aR operation ensures ultra-fast clearing to protect semiconductor devices before damaging overcurrents develop
- 250 A Current Rating — handles heavy continuous load currents typical in industrial drive and converter systems
- 690 V AC / 450 V DC Dual Voltage Rating — suitable for both AC and DC bus protection in modern drive architectures
- 200 kA Breaking Capacity — high interrupt rating ensures reliable fault clearing even on stiff industrial supply networks
- BS88 Part 4 / IEC 60269-4 Compliant — internationally recognized standard ensures interchangeability and predictable protection performance
- Single Barrel Form Factor — compact, standardized BS88 body simplifies panel design and fuse holder selection
- CE Marked and RoHS Compliant — meets European regulatory requirements for export and domestic panel builders
- IEC Rated and UL Recognized — dual certification supports global OEM and project specifications
- Low I²t Let-Through — minimizes thermal and electromagnetic stress on downstream semiconductor components during fault events
Technical Specifications
| Specification | Value |
|---|---|
| Catalog Number | 250MT |
| Series | Bussmann MT |
| Fuse Type | High Speed British Standard, Single Barrel |
| Fuse Class | Class aR |
| Amperage Rating | 250 A |
| Voltage Rating (AC) | 690 V |
| Voltage Rating (DC) | 450 V |
| Breaking Capacity | 200 kA |
| Standard | BS88 Part 4, IEC 60269-4 |
| Compliances | CE Marked, RoHS Compliant |
| Certifications | IEC Rated, UL Recognized |
| Application | Semiconductor protection, DC drives, VFDs, power converters, rectifiers, soft starters, thyristor stacks, DC common bus |
Applications & Selection Guide
The 250MT is the correct choice when semiconductor devices must be protected against overcurrents and short-circuit conditions in high-power drive and converter panels. Class aR fuses are specifically characterized for semiconductor protection — unlike general-purpose gG fuses, they are not intended to carry overload currents for extended periods but are optimized for the rapid, current-limiting clearing action that prevents IGBT, thyristor, and diode junctions from being destroyed. The 250 A rating suits medium-to-large drive systems and converter stacks operating at AC supply voltages up to 690 V or DC bus voltages up to 450 V.
In Indian industrial environments, this fuse finds regular use in VFD panels for heavy-duty motor drives in cement, steel, textile, paper, and water treatment plants, as well as in rectifier assemblies and UPS systems in data centres and manufacturing facilities across Coimbatore, Chennai, Pune, and Ahmedabad. DC common bus architectures in multi-drive systems particularly benefit from the 450 V DC rating of the 250MT. Panel builders and OEMs specifying Eaton Bussmann semiconductor fuses for 415 V or 690 V systems will find the MT series a well-established, widely stocked solution.
When selecting the 250MT, verify that the fuse holder or fuse base is rated and dimensioned for the BS88 single barrel body and is compatible with 250 A continuous current at the ambient temperature of the enclosure. Coordinate the fuse’s I²t characteristics with the semiconductor manufacturer’s published I²t withstand rating to confirm adequate protection margin. Shansen Enterprises can assist with fuse-holder cross-referencing and coordination studies for your panel design.
Why Buy from Shansen Enterprises?
- Authorized Eaton Channel Partner in Coimbatore — guaranteed genuine Eaton Bussmann product
- 100% genuine products supplied with manufacturer warranty and traceability
- Pan-India delivery to all major industrial cities and project sites
- WhatsApp technical support for fuse selection, coordination, and sizing queries
- Competitive bulk pricing for panel builders, OEMs, EPC contractors, and system integrators
Compatible Products & Accessories
- Eaton Bussmann BS88 Single Barrel Fuse Holders and Fuse Bases (matching MT series body)
- Eaton Bussmann MT Series Semiconductor Fuses (other current ratings in the MT range)
- Eaton Bussmann Fuse Monitoring and Blown-Fuse Indication Accessories
- Eaton Bussmann Ferrule and Bolted Tag Fuse Links for upstream branch circuit protection
- Eaton DIN Rail Fuse Holders for panel integration
- Thyristor modules, IGBT modules, and rectifier bridge assemblies (protected loads)
Frequently Asked Questions
What does Class aR mean and why does the 250MT use this class?
Class aR (accompanying Range) is an IEC fuse utilization category defined specifically for semiconductor protection. Unlike general-purpose Class gG fuses that must clear both overloads and short circuits, aR fuses are designed to clear only in the high-current fault range with extremely fast action, producing very low I²t let-through values that keep thermal energy within the safe withstand capability of semiconductor junctions. The 250MT uses Class aR because it is intended to protect thyristors, IGBTs, diodes, and similar devices in drive and converter circuits where a general-purpose fuse would be too slow and would allow destructive energy to reach the semiconductor before clearing.
Can the 250MT be used for both AC and DC circuit protection?
Yes. The Eaton Bussmann 250MT carries a dual voltage rating — 690 V AC and 450 V DC — making it suitable for protection on both AC supply-side circuits and DC bus circuits within drive and converter systems. This makes it particularly valuable for DC common bus architectures where multiple drives share a rectified DC rail, as well as for traditional AC-fed semiconductor assemblies. Always verify the actual circuit voltage does not exceed the appropriate rated voltage for the connection type.
What is the breaking capacity of the 250MT and why does it matter?
The 250MT has a breaking capacity of 200 kA, meaning it is capable of safely interrupting fault currents up to 200 kA without rupturing, arcing externally, or losing its containment integrity. In Indian industrial installations connected to high-capacity MV/LV transformer feeders, prospective short-circuit currents at the panel busbars can be very high. A breaking capacity of 200 kA ensures the fuse remains a reliable protective device even in the most demanding supply configurations encountered in large industrial plants and substations.
Is the 250MT a direct replacement for other BS88 Part 4 semiconductor fuses of the same rating?
The 250MT conforms to BS88 Part 4 and IEC 60269-4, so it shares the standardized single barrel body dimensions associated with the BS88 form factor at this current rating. However, I²t and time-current characteristics can differ between manufacturers and series. Before substituting the 250MT for another make or type, cross-check the I²t pre-arcing and total clearing values against the semiconductor device’s published withstand rating to confirm adequate protection. Shansen Enterprises can provide Eaton Bussmann characteristic data sheets and assist with the coordination check.
What industries in India commonly use the Eaton Bussmann 250MT?
The 250MT is widely used across heavy and process industries in India where variable frequency drives, soft starters, DC drives, and rectifier assemblies are common. Typical sectors include textile mills and spinning units in Coimbatore and Tiruppur, steel rolling mills and furnace controls, cement plant kiln drives, water and wastewater treatment pump drives, paper and pulp processing, automotive manufacturing lines, and large HVAC and data centre UPS systems. Panel builders and drive OEMs supplying these sectors regularly stock the MT series for semiconductor protection duties.
How do I order the Eaton Bussmann 250MT from Shansen Enterprises?
You can request a quote for the Eaton Bussmann 250MT directly from Shansen Enterprises by clicking the WhatsApp button on this page or by sending an email through the Contact Us form. Please mention the catalog number 250MT, the quantity required, and your delivery location so we can confirm availability, lead time, and the best price. Shansen Enterprises is an authorized Eaton channel partner in Coimbatore and supplies genuine Eaton Bussmann fuses with full warranty and documentation to customers across India including Chennai, Bengaluru, Mumbai, Pune, Hyderabad, and Ahmedabad.
