Description
Overview
The Eaton Bussmann 225MMT is a high-speed, double barrel, BS88-type semiconductor protection fuse rated 225 A at 690 V AC and 450 V DC, belonging to the Bussmann MMT series. Built to IEC 60269-4 and BS88 Part 4 standards, it offers an exceptional breaking capacity of 200 kA, ensuring rapid fault clearance before semiconductor junction temperatures reach destructive levels. It carries CE marking, RoHS compliance, IEC rating, and UL recognition, making it suitable for use in both Indian and global installations.
Key Features
- High-Speed Current Limiting — Double barrel construction enables ultra-fast arc extinction, protecting thyristors, diodes, IGBTs, and MOSFETs from thermal damage during fault events.
- 225 A Current Rating — Precisely rated for medium-power semiconductor drive and converter applications without nuisance tripping under normal operating loads.
- 690 V AC / 450 V DC Rated — Dual voltage capability covers the full range of industrial AC drive systems and DC bus configurations in a single part number.
- 200 kA Breaking Capacity — Handles the highest prospective fault currents found in industrial switchgear and power conversion panels.
- Class aR Rating — Back-up semiconductor protection class designed specifically to operate only on high fault currents, coordinating correctly with semiconductor device I²t ratings.
- IEC 60269-4 / BS88 Part 4 Compliant — Meets international standards for semiconductor protection fuses, ensuring traceability and design approval in certified panels.
- CE Marked & RoHS Compliant — Accepted in CE-marked equipment exported from India; meets hazardous substance restrictions for modern panel assemblies.
- IEC Rated & UL Recognized — Dual certification simplifies approval of panels destined for both domestic Indian installations and export markets.
- Bussmann MMT Series — Consistent dimensional envelope across the MMT range simplifies spares management and panel design standardization for OEMs and panel builders.
Technical Specifications
| Specification | Value |
|---|---|
| Catalog Number | 225MMT |
| Series | Bussmann MMT |
| Fuse Type | High Speed British Standard, Double Barrel |
| Amperage Rating | 225 A |
| Rated Voltage AC | 690 V |
| Rated Voltage DC | 450 V |
| Breaking Capacity | 200 kA |
| Fuse Class | Class aR |
| 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 225MMT is engineered for use wherever semiconductor devices must be protected from destructive fault currents in industrial power electronics. It is particularly suited to AC and DC variable frequency drives (VFDs), soft starters, thyristor-based rectifiers, SCR power controllers, IGBT converters, and DC common bus architectures commonly found in continuous process industries, steel plants, paper mills, textile machinery, and renewable energy inverter systems across India.
Class aR fuses like the 225MMT are back-up semiconductor protection devices — they are intended to operate at high multiples of rated current and must always be coordinated with the semiconductor device’s published I²t withstand value. Panel designers should verify that the fuse I²t (let-through) at the prospective fault current is less than the device I²t rating. The 225MMT should not be used as the sole branch-circuit overload protection; a separate contactor or circuit breaker handles overload while the aR fuse handles fault protection.
In the Indian industrial context, this fuse is widely specified by OEM drive manufacturers, panel builders in Coimbatore, Chennai, Pune, and Ahmedabad, and EPC contractors supplying MCC and drive panels to automotive, chemical, cement, and water treatment sectors. Its 690 V AC rating covers standard 415 V and 690 V Indian grid systems with adequate voltage margin.
Why Buy from Shansen Enterprises?
- Authorized Eaton Channel Partner in Coimbatore — genuine Bussmann products with full traceability
- 100% genuine products supplied with original Eaton warranty and documentation
- Pan-India delivery to all major industrial cities and Tier-2 locations
- WhatsApp technical support for product selection, cross-reference, and panel design queries
- Bulk pricing and scheduled supply agreements for panel builders, OEMs, and EPC contractors
Compatible Products & Accessories
- Bussmann MMT Series fuse holders and fuse bases compatible with double barrel BS88 fuse links
- Eaton Bussmann semiconductor protection fuses in adjacent ratings (e.g., 200MMT, 250MMT) for coordinated protection design
- Eaton Bussmann Class gR fuses for combined overload and short-circuit protection where aR coordination is not required
- Eaton semiconductor contactors and thyristor power controllers for complete drive protection assemblies
- Eaton Bussmann fuse status indicators and blown fuse monitoring accessories for panel alarm integration
- DIN rail and busbar-mounted fuse carrier assemblies for MMT series fuse links
Frequently Asked Questions
What is the difference between a Class aR and a Class gR semiconductor fuse?
A Class aR fuse is a back-up semiconductor protection fuse — it operates only at high fault currents and does not provide full-range overload protection. It must be coordinated with a separate overload protective device such as a circuit breaker or contactor. A Class gR fuse provides full-range protection, handling both overload currents and short-circuit fault currents. The 225MMT is a Class aR device, so panel designers must ensure appropriate overload protection is provided upstream or in parallel to achieve complete system protection.
Why does the 225MMT have both an AC voltage rating of 690 V and a DC voltage rating of 450 V?
AC and DC arc extinction behave differently — DC arcs are harder to interrupt because the current does not pass through natural zero crossings as in AC systems. Consequently, a fuse rated 690 V AC is typically derated to a lower DC voltage, in this case 450 V DC, to ensure reliable arc interruption at rated breaking capacity. The 225MMT’s 450 V DC rating makes it directly applicable to standard 6-pulse and 12-pulse rectifier DC bus voltages derived from 415 V AC supplies in Indian industrial installations.
Can the 225MMT be used to protect IGBTs and MOSFETs in addition to thyristors and diodes?
Yes. The 225MMT is suitable for protecting a broad range of semiconductor power devices including SCRs (thyristors), diodes, IGBTs, and MOSFETs, provided that the fuse’s I²t let-through value at the installation’s prospective fault current is confirmed to be less than the semiconductor device’s rated I²t withstand. Always consult the semiconductor device datasheet and the Eaton Bussmann fuse time-current characteristic curves, or contact Shansen Enterprises for application-specific selection support.
Is the 225MMT suitable for use in variable frequency drives (VFDs) installed in India?
Yes. The 225MMT is explicitly rated for VFD semiconductor protection and is commonly specified in drive input and DC bus protection circuits for Indian industrial VFD panels operating on 415 V, 50 Hz supply systems. Its 690 V AC rating provides the necessary voltage margin above the 415 V system voltage, and its 200 kA breaking capacity covers the fault levels found in most Indian industrial switchboards. It is used in drives for pumps, fans, compressors, conveyors, and other motor-driven applications across manufacturing and infrastructure sectors in India.
What fuse holder or fuse base is compatible with the 225MMT double barrel fuse?
The 225MMT uses the standard Bussmann MMT series double barrel BS88 fuse body dimensions. Compatible fuse holders and fuse bases are available in the Eaton Bussmann accessory range for the MMT series. Please contact Shansen Enterprises with your application details — including panel layout, busbar configuration, and current rating — and our technical team will recommend the correct matching fuse carrier, base, or rail-mount assembly for your installation in Coimbatore or anywhere across India.
How do I order the Eaton Bussmann 225MMT from Shansen Enterprises?
Ordering the 225MMT from Shansen Enterprises is straightforward. You can reach us via WhatsApp or email using the contact buttons on this page — quote the catalog number 225MMT along with your required quantity, delivery location, and any project or panel details. Our team will respond promptly with pricing, availability, and lead time. We supply genuine Eaton Bussmann products with full documentation and deliver pan-India to industrial customers, panel builders, OEMs, and EPC contractors. Bulk orders attract preferential pricing and scheduled delivery options.
