Description
Overview
The Eaton Bussmann 400FMM is a high speed, Class aR double barrel fuse from the Bussmann FMM series, rated at 400 A and 690 V AC (450 V DC) with a 200 kA breaking capacity. Designed specifically for semiconductor protection, it meets BS88 Part 4 and IEC 60269-4 standards and carries CE marking, RoHS compliance, IEC rating, and UL recognition. Its ultra-fast current-limiting action ensures that fault energy is arrested before it can damage IGBTs, thyristors, diodes, or other sensitive power semiconductor devices.
Key Features
- High Speed Class aR Rating — Ultra-fast operation limits I²t let-through energy to protect semiconductor junctions during fault events.
- Double Barrel Construction — Dual fuse element barrels enhance current interruption reliability and thermal performance in high-current applications.
- 200 kA Breaking Capacity — Handles extreme prospective fault currents common in industrial power systems across India.
- Wide Voltage Coverage — Rated 690 V AC and 450 V DC, suitable for both AC drives and DC bus architectures.
- 400 A Amperage Rating — Matches high-current power converter and drive applications without oversizing.
- BS88 Part 4 / IEC 60269-4 Compliance — Meets internationally recognized standards for semiconductor fuse performance.
- CE Marked & RoHS Compliant — Meets European regulatory requirements; safe for use in environmentally conscious designs.
- IEC Rated & UL Recognized — Dual certification eases specification for global OEMs and export-oriented panel builders in India.
- Minimal Arc Energy — Fast-acting element design reduces arc duration, protecting downstream semiconductor devices from thermal runaway.
Technical Specifications
| Specification | Value |
|---|---|
| Catalog Number | 400FMM |
| Series | Bussmann FMM |
| Fuse Type | High Speed British Standard Double Barrel |
| Fuse Class | Class aR |
| Amperage Rating | 400 A |
| Rated Voltage AC | 690 V |
| Rated Voltage 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 400FMM is the preferred choice for engineers protecting high-power semiconductor devices in variable frequency drives (VFDs), DC drives, rectifier bridges, thyristor stacks, soft starters, and power converters operating at up to 690 V AC or 450 V DC. The Class aR rating denotes a fuse optimized exclusively for semiconductor protection — it operates faster than general-purpose Class gG fuses and provides the low I²t let-through values required to keep IGBTs, SCRs, and diodes within their safe operating area during short circuit conditions.
In Indian industrial environments — including Coimbatore’s textile machinery sector, automotive manufacturing corridors, and large-scale HVAC and pumping installations — high prospective fault currents from low-impedance transformers and long bus runs make a 200 kA rated fuse essential. The 400FMM’s double barrel format is frequently specified in panel builders’ designs for motor control centers, converter cabinets, and regenerative drive panels where space and heat dissipation are critical constraints.
When selecting the correct FMM fuse, verify that the fuse’s rated voltage meets or exceeds your system voltage, that the amperage rating aligns with the semiconductor’s maximum non-repetitive surge current (IFSM) characteristics, and that the fuse’s I²t clearing value is below the semiconductor’s I²t withstand rating. Consult the Eaton Bussmann fuse–semiconductor coordination tables or contact Shansen Enterprises for application-specific selection support.
Why Buy from Shansen Enterprises?
- Authorized Eaton Channel Partner in Coimbatore — genuine products with full manufacturer traceability
- 100% genuine Eaton Bussmann fuses supplied with manufacturer warranty
- Pan-India delivery to all major industrial hubs including Chennai, Bengaluru, Hyderabad, Pune, Mumbai, and Delhi
- WhatsApp technical support for fuse selection, coordination studies, and urgent replacement queries
- Bulk pricing and project-based supply for panel builders, OEMs, EPC contractors, and system integrators
Compatible Products & Accessories
- Eaton Bussmann FMM Series Fuse Holders and Fuse Bases for double barrel BS88 fuses
- Eaton Bussmann FMM Series companion fuses in adjacent current ratings (315 A, 450 A, 500 A) for coordinated protection schemes
- Eaton Bussmann semiconductor protection fuses — High Speed Square Body (170M series) for alternative form factors
- DIN rail and busbar-mounted fuse carriers compatible with BS88 double barrel fuse links
- Eaton surge protection devices (SPDs) for upstream transient voltage protection in VFD and converter panels
- Eaton motor protection circuit breakers and contactors for downstream motor circuit coordination
Frequently Asked Questions
What does Class aR mean and how is the 400FMM different from a standard gG fuse?
Class aR (accompanying Range) fuses are designed exclusively for semiconductor protection. Unlike Class gG fuses, which must protect both cables and equipment across a full overload and short circuit range, Class aR fuses are optimized to operate at high speed during short circuit conditions, limiting I²t let-through energy to a level safe for semiconductor junctions. The 400FMM will not protect cables against overload on its own — it must be used in conjunction with a suitably rated circuit breaker or other overload protection device.
Can the 400FMM be used in DC applications such as common bus drives?
Yes. The Eaton Bussmann 400FMM is rated at 450 V DC in addition to its 690 V AC rating, making it suitable for DC common bus drive systems, battery-backed converter systems, and DC-side protection in rectifier assemblies. Always confirm that the DC system voltage does not exceed 450 V DC and that the fuse’s DC breaking capacity is adequate for the prospective fault current at the installation point.
What is the breaking capacity of the 400FMM and why does it matter for Indian industrial installations?
The 400FMM has a breaking capacity of 200 kA. This means it can safely interrupt prospective fault currents up to 200 kA without rupture or fire hazard. In Indian industrial facilities fed by large distribution transformers or with multiple parallel supply feeders, prospective fault levels at the point of installation can be very high. Using a fuse with a breaking capacity equal to or greater than the calculated prospective fault current is a mandatory safety and compliance requirement under IEC 60269-4.
Is the Eaton Bussmann 400FMM UL recognized for use in export equipment?
Yes. The 400FMM carries UL Recognized Component status in addition to IEC rating and CE marking. This makes it a valid choice for Indian OEMs and panel builders manufacturing equipment for export to North American or European markets, as well as for domestic installations that require UL-recognized components to satisfy end-customer or insurance specifications.
How do I verify that the 400FMM is the correct fuse to protect my specific IGBT module or thyristor?
Semiconductor fuse selection requires matching the fuse’s I²t clearing value (at the system voltage and prospective fault current) to a value below the semiconductor device’s published I²t withstand rating. You should also verify that the fuse’s peak let-through current (Ip) does not exceed the semiconductor’s repetitive peak current rating. Eaton Bussmann publishes detailed time-current characteristic curves and I²t data for the FMM series. The Shansen Enterprises technical team in Coimbatore can assist with coordination calculations — contact us via WhatsApp or email with your semiconductor datasheet and system parameters.
How do I order the Eaton Bussmann 400FMM from Shansen Enterprises?
You can request a quote for the Eaton Bussmann 400FMM directly through the Shansen Enterprises website at shansenenterprises.com by clicking the WhatsApp or email quote button on this product page. Share your required quantity, delivery location, and any project details, and our team will respond promptly with pricing and availability. We supply genuine Eaton Bussmann fuses with manufacturer warranty and offer pan-India delivery from our Coimbatore base to all major industrial cities including Chennai, Bengaluru, Hyderabad, Pune, and Mumbai.
