Description
Overview
The Eaton Bussmann 170M6766 is a high speed square body semiconductor protection fuse rated at 1250 A and 690 V AC, forming part of the well-established Bussmann 170M Series. Manufactured to IEC 60269-4 and carrying CE, RoHS, IEC, UL, and CSA credentials, this fuse is engineered to provide ultra-fast current limitation specifically for silicon-controlled rectifiers, IGBTs, thyristors, and other semiconductor devices that cannot withstand the let-through energy of a standard overcurrent protective device. The 3FKE/115 square body format with bolt-in connections ensures reliable mechanical mounting and low-resistance electrical contact in high-current power conversion equipment.
Key Features
- 1250 A Current Rating — suitable for high-power converter, drive, and rectifier circuits requiring reliable semiconductor protection at elevated current levels
- 690 V AC Rated Voltage — compatible with standard 415 V and 690 V industrial power systems widely used across India
- 200 kA Breaking Capacity — exceptional fault current interruption capability ensuring personnel and equipment safety under worst-case short-circuit conditions
- Class aR Performance — current-limiting action engineered specifically for semiconductor protection, responding faster than gG or gR class fuses to limit I²t let-through to semiconductor-safe levels
- IEC 60269-4 Compliance — meets the international standard governing semiconductor fuses, ensuring predictable and verifiable protection coordination
- 3FKE/115 Square Body Format — industry-standard square body form factor simplifies replacement and sourcing across OEM and panel-builder environments
- Bolt-In Connections — positive mechanical contact reduces contact resistance and provides vibration-resistant termination in demanding drive panel environments
- CE Marked and RoHS Compliant — meets European conformity and hazardous substance requirements, supporting export-oriented machinery manufacturers in India
- UL/CSA Listed — dual certification supports equipment destined for North American markets as well as domestic IEC applications
- No External Fuse Indicator — clean panel aesthetic; blown-fuse detection is managed by circuit monitoring or drive fault outputs in typical system designs
Technical Specifications
| Specification | Value |
|---|---|
| Catalog Number | 170M6766 |
| Series | Bussmann 170M |
| Amperage Rating | 1250 A |
| Rated Voltage AC | 690 V |
| Breaking Capacity | 200 kA |
| Interrupt Rating | 200 kA |
| Fuse Class | Class aR |
| Construction / Body Format | Square body 3FKE/115 |
| Connection Type | Bolt-in |
| Fuse Indicator | None |
| Standard | IEC 60269-4 |
| Compliances | CE Marked, RoHS Compliant |
| Certifications | IEC Rated, UL/CSA Listed |
| Application | Semiconductor protection, DC common bus, DC drives, power converters, rectifiers, VFDs, soft starters, thyristor stacks |
Applications & Selection Guide
The 170M6766 is the correct selection for engineers designing protection schemes around high-current semiconductor assemblies operating at up to 690 V AC. Its Class aR rating means it is specifically current-calibrated for semiconductor let-through energy (I²t) limits — it must not be substituted with general-purpose gG or motor-rated gM fuses, which are too slow to prevent semiconductor junction damage during fault conditions. Typical applications include the DC bus protection of variable frequency drives (VFDs), input and output protection of thyristor power controllers, soft starter bypass protection, and rectifier bridge fusing in industrial UPS and electrochemical process equipment.
In India’s rapidly expanding manufacturing, infrastructure, and renewable energy sectors, high-power drive systems and power converters are increasingly common in steel plants, cement mills, water treatment facilities, textile machinery, and solar inverter farms. The 170M6766 addresses the fusing requirements of these high-fault-current environments where plant engineers must balance fast semiconductor protection with coordination across upstream MCCBs and ACBs. The 200 kA breaking capacity provides adequate margin even on stiff MV/LV transformer feeds typical of large industrial substations in Tamil Nadu and across India.
When selecting this fuse, confirm that the I²t let-through value at the prospective fault current of your system is within the semiconductor manufacturer’s published withstand rating. Eaton Bussmann provides detailed I²t and peak let-through current curves for the 170M Series to support this coordination exercise. Shansen Enterprises can assist panel builders and OEMs in Coimbatore and across India with application selection, cross-reference checks, and volume procurement planning.
Why Buy from Shansen Enterprises?
- Authorized Eaton Channel Partner in Coimbatore — genuine products with full manufacturer traceability
- 100% genuine Eaton Bussmann products supplied with warranty and original documentation
- Pan-India delivery to Chennai, Bangalore, Mumbai, Pune, Hyderabad, Delhi, and beyond
- WhatsApp technical support for application selection, cross-references, and protection coordination queries
- Bulk pricing and scheduled delivery programs available for panel builders, OEMs, and EPC contractors
Compatible Products & Accessories
- Eaton Bussmann 170M Series fuse holders and fuse bases for 3FKE/115 square body format
- Eaton Bussmann 170M Series companion fuses at adjacent current ratings (e.g., 1000 A, 1400 A) for system coordination
- Eaton Bussmann striker-pin fuse indicator accessories (where panel design requires external blown-fuse signaling)
- Eaton DIN rail mounting adapters and copper bus bar connectors compatible with bolt-in square body fuses
- Eaton Bussmann Class aR fuses at lower voltage ratings for 400 V AC drive systems
- Eaton electronic fuse monitoring relays for remote blown-fuse alarm in unmanned drive panels
Frequently Asked Questions
What does Class aR mean and why is it required for semiconductor protection?
Class aR (aR = current-limiting, semiconductor protection range) denotes a fuse designed to operate only in the overcurrent range where semiconductor devices are at risk of destruction — typically from around 3× to 10× rated current upward. Unlike general-purpose Class gG fuses, a Class aR fuse has a very low let-through I²t value calibrated to stay below the semiconductor junction’s published withstand I²t. This means when a fault occurs, the fuse clears before the semiconductor device absorbs enough energy to fail. Using a gG fuse in place of an aR fuse on a thyristor or IGBT drive is a common engineering error that results in repeated semiconductor failures even though the fuse itself may not blow.
Can the 170M6766 be used on a 415 V AC system in India?
Yes. A fuse rated at 690 V AC is fully suitable for use on a 415 V AC system — voltage ratings on fuses are maximum operating voltage limits, not nominal system voltage requirements. Using a 690 V rated fuse on a 415 V system provides additional voltage withstand margin and is standard practice. The 1250 A current rating and Class aR I²t characteristics remain unchanged regardless of whether the fuse is applied at 415 V or 690 V.
Is the 170M6766 suitable for DC bus applications in VFD panels?
Yes. Eaton Bussmann lists DC common bus and DC drives among the primary applications for this fuse. However, the DC voltage rating must be confirmed against the fuse’s published DC voltage specification from the Eaton datasheet before installation. DC arc interruption imposes different demands on a fuse than AC interruption, and the permissible DC voltage is typically lower than the AC voltage rating. Contact Shansen Enterprises or refer to the Eaton Bussmann 170M Series datasheet for the specific DC voltage rating of the 170M6766.
What is the body format of the 170M6766 and which fuse holders are compatible?
The 170M6766 uses the 3FKE/115 square body format with bolt-in connections. This is a standardized high-speed square body form factor used across the Eaton Bussmann 170M Series and is compatible with matching Eaton Bussmann fuse holders, DIN rail bases, and bus bar mounting hardware designed for the 3FKE/115 envelope. Always verify the mechanical dimensions and hole spacing from the product datasheet when designing a new panel, and confirm with Shansen Enterprises if you require compatible mounting hardware as part of your order.
Does the 170M6766 have a fuse indicator or striker pin?
No. The 170M6766 does not include a built-in fuse indicator or striker pin. Blown-fuse detection in systems using this fuse is typically handled through drive fault outputs, current monitoring relays, or external electronic fuse monitoring modules. If your panel design requires visual indication or remote signaling of a blown fuse, Eaton Bussmann offers optional striker and indicator accessories for the 170M Series — Shansen Enterprises can advise on compatible options for your specific application.
How do I order the Eaton Bussmann 170M6766 from Shansen Enterprises?
You can request a quote for the 170M6766 directly through Shansen Enterprises by clicking the WhatsApp button on this page or by sending an email via the contact form. Please mention the catalog number 170M6766, the required quantity, and your delivery location in India. Our team in Coimbatore will respond promptly with pricing, availability, and estimated delivery timeline. Bulk orders for panel builders and OEMs are welcome, and we can arrange scheduled deliveries to support your production planning.
