Description
Overview
The Eaton Bussmann 170M7309 is a 1250 A, 690 V AC high speed square body semiconductor fuse from the proven Bussmann 170M Series, rated to IEC 60269-4 with a 200 kA interrupt rating and Class aR current-limiting performance. Its 3TN/80 square body format with bolt-in connections makes it a standard choice for engineered protection of DC common bus assemblies, power converters, and variable frequency drives in industrial installations across India. At 1250 A, this fuse is positioned for high-current semiconductor protection where conventional fuses cannot respond fast enough to prevent device damage.
Key Features
- 1250 A Amperage Rating — handles high-current semiconductor protection duties without derating in well-ventilated enclosures
- 690 V AC Rated Voltage — suitable for standard industrial 3-phase LV distribution systems widely used across Indian manufacturing facilities
- 200 kA Breaking Capacity — provides robust fault current interruption in high-prospective-fault environments such as bus bars and converter cabinets
- Class aR Rating — purpose-built for semiconductor protection, faster than gG fuses, limiting peak let-through current to protect thyristors, IGBTs, and diodes
- 3TN/80 Square Body Format — industry-standard footprint ensuring interchangeability and compatibility with existing fuse holders and busbars
- Bolt-In Connections — provides low contact resistance and vibration-resistant termination ideal for high-current industrial panel assemblies
- IEC 60269-4 Compliant — meets international standards for high speed fuses used in semiconductor protection applications
- CE Marked & RoHS Compliant — satisfies European and global regulatory requirements, supporting export-oriented Indian OEM panel builders
- No Fuse Indicator — compact, simplified design optimised for space-constrained installations where external monitoring is handled by the control system
Technical Specifications
| Specification | Value |
|---|---|
| Catalog Number | 170M7309 |
| Series | Bussmann 170M |
| Amperage Rating | 1250 A |
| Voltage Rating (AC) | 690 V |
| Interrupt Rating | 200 kA |
| Breaking Capacity | 200 kA |
| Fuse Class | Class aR |
| Construction | Square body 3TN/80 format with bolt-in connections |
| Fuse Indicator | None |
| Standard | IEC 60269-4 |
| Compliances | CE Marked, RoHS Compliant |
| Certifications | IEC Rated |
| Application | Semiconductor protection, DC common bus, DC drives, power converters, rectifiers, VFDs, soft starters, thyristor stacks |
Applications & Selection Guide
The 170M7309 is specified wherever fast-acting semiconductor protection is required at 1250 A and 690 V AC. Typical installations include DC common bus drive systems, multi-drive panels, front-end rectifiers, thyristor converters, and large VFD input stages used in steel plants, cement factories, chemical process lines, and water treatment facilities across India. At this current rating, the fuse is commonly found protecting the DC bus or AC input of high-power soft starters and regenerative drives.
Class aR fuses are not interchangeable with Class gG general-purpose fuses — aR fuses are designed exclusively for semiconductor protection and do not provide overload protection for cables. Always pair this fuse with appropriate upstream gG or gL protection for the feeder circuit. The 3TN/80 square body format is compatible with standard Eaton Bussmann and third-party fuse holders designed for this body size, making panel upgrades and replacements straightforward for Indian panel builders and system integrators.
Indian industries investing in energy efficiency drives, automation upgrades, and renewable energy integration commonly specify 170M Series fuses for their converter panels. The 200 kA breaking capacity is particularly valuable in facilities fed directly from medium-voltage transformers with high available fault current, ensuring semiconductor devices are protected even under worst-case bolted fault conditions.
Why Buy from Shansen Enterprises?
- Authorized Eaton Channel Partner in Coimbatore — genuine products with full manufacturer backing
- 100% genuine Eaton Bussmann products supplied with warranty and documentation
- Pan-India delivery to all major industrial hubs including Chennai, Bengaluru, Mumbai, Pune, Hyderabad, and beyond
- WhatsApp technical support for application selection, cross-referencing, and replacement guidance
- Bulk pricing available for panel builders, OEMs, system integrators, and EPC contractors
Compatible Products & Accessories
- Eaton Bussmann 170M Series fuse holders and fuse bases for 3TN/80 square body format
- Eaton Bussmann 170M Series fuses at adjacent current ratings (1000 A, 1100 A, 1400 A) for drive panel coordination studies
- Eaton Bussmann fuse monitoring and blown fuse indication accessories
- Eaton Bussmann NH fuse links for upstream feeder protection coordination
- Copper busbars and bolt-in terminal hardware compatible with 170M 3TN/80 fuse bodies
- DIN rail mounted fuse holders and panel mount adapters for 170M Series integration
Frequently Asked Questions
What does Class aR mean for the Eaton Bussmann 170M7309 and how does it differ from Class gG?
Class aR (current-limiting, restricted range) fuses like the 170M7309 are specifically engineered for semiconductor protection. They operate extremely fast under short-circuit conditions to limit peak let-through current and protect thyristors, diodes, and IGBTs. Unlike Class gG fuses, which provide both overload and short-circuit protection for general use, aR fuses only protect within their restricted operating range — they do not protect against sustained overloads. Always use a separate upstream gG or gL fuse for cable and feeder protection in the same circuit.
Is the 170M7309 suitable for DC bus protection in VFD and drive panels?
Yes. The Eaton Bussmann 170M Series is one of the most widely specified high speed fuse families for DC common bus and AC input protection of variable frequency drives, soft starters, and power converters. The 170M7309 at 1250 A and 690 V AC is suited for high-power drive panels where fast current limitation is critical to prevent damage to the inverter bridge or rectifier stack. Always verify the fuse I²t and peak let-through current values against the semiconductor device’s rated I²t to confirm coordination.
What fuse holder or fuse base is compatible with the 170M7309?
The 170M7309 uses the 3TN/80 square body format with bolt-in connections. Compatible fuse holders and mounting hardware are available from Eaton Bussmann for the 170M Series. Shansen Enterprises can help identify the correct fuse holder, busbar adapter, or panel mount base for your specific installation. Contact us via WhatsApp or email with your panel layout details for a recommendation.
What is the breaking capacity of the 170M7309 and why does it matter?
The 170M7309 has a breaking capacity of 200 kA, meaning it can safely interrupt fault currents up to 200 kA without rupturing or causing secondary damage. This is particularly important in industrial facilities in India fed from large transformers or low-impedance busbars where prospective fault current levels can be very high. Specifying a fuse with adequate breaking capacity ensures personal safety, equipment integrity, and compliance with electrical installation standards.
Does the Eaton Bussmann 170M7309 come with a fuse indicator?
No, the 170M7309 does not include a built-in fuse indicator. For applications requiring blown fuse detection, Eaton Bussmann offers separate fuse monitoring accessories and indicator options in the 170M Series range. Alternatively, many modern drive and converter control systems include DC bus voltage monitoring that effectively serves as blown fuse detection. Shansen Enterprises can advise on compatible monitoring solutions for your panel design.
How do I order the Eaton Bussmann 170M7309 from Shansen Enterprises?
You can request a quote for the Eaton Bussmann 170M7309 directly from Shansen Enterprises by clicking the WhatsApp button on this page or sending an email to our sales team. Please mention the catalog number 170M7309 and your required quantity. We supply genuine Eaton Bussmann products across India with competitive pricing for both single pieces and bulk orders. Our team in Coimbatore can also assist with datasheet verification, application support, and delivery scheduling to your site.
