Eaton Bussmann 170M5715 690V AC aR Fuse – 61 x 77 x 135mm, 318g

Description

Application Scenarios

In a 2MW DC drive system at a steel processing plant, frequent IGBT module failures were traced to inadequate protection—the standard gG-class fuses in use took too long to clear faults, allowing destructive short-circuit currents to pass through the semiconductors. After engineers replaced them with the Eaton Bussmann 170M5715 fuses, the drive system’s protection performance improved dramatically. The aR-class fuse’s <1μs pre-arc time and 125,000 A²s pre-arc I²t ensured that fault currents were interrupted before they could exceed the IGBT’s safe operating area. The plant reported zero semiconductor failures over 18 months following the upgrade, eliminating unplanned downtime costing an estimated $40,000 per incident.

The 170M5715 is the go-to solution for DC common bus systems where multiple drives share a single DC supply. In these architectures, a fault on one drive can cause the entire bus to collapse if not isolated quickly. The fast-acting 170M5715 ensures that the faulty branch is disconnected before the fault propagates to other drives on the bus . It is equally indispensable in power converter/rectifier stations for electrolytic processes, where continuous operation and equipment longevity are paramount. Whether protecting six-pulse thyristor rectifiers in aluminum smelters or IGBT inverters in high-speed elevators, the Eaton Bussmann 170M5715 delivers the predictable, ultra-fast interruption that power electronics demand.

Parameters

Technical Principles and Innovative Values

Innovation Point 1: Ultra-Fast aR-Class Response vs. Standard Fuses
The Eaton Bussmann 170M5715 belongs to the aR utilization category, which is specifically defined for semiconductor protection. Unlike gG or gL “general purpose” fuses that can take tens of milliseconds to clear faults, the aR class is designed with an extremely fast pre-arc time . This is not a trade-off but a deliberate design: power semiconductors like IGBTs can withstand short-circuit conditions for only a few milliseconds before thermal destruction occurs. The 170M5715 matches this protection window, interrupting fault currents before the device’s junction temperature reaches critical limits. The pre-arc I²T of 125,000 A²s is the key parameter engineers use to verify that the fuse will clear before the semiconductor’s tolerable I²T is exceeded .

Innovation Point 2: Engineered Silver Element for Predictable Melting
The internal construction of the 170M5715 features precision-formed silver elements with controlled notches. These notches create defined hot spots during overloads, ensuring that the fuse’s melting characteristic is both fast and consistent—batch to batch, year to year . The silver material offers low electrical resistance, which translates to minimal steady-state power loss (110W at 900A) and reduced heat generation in the fuse holder. When a fault occurs, the silver elements vaporize almost instantly, and the high-purity quartz sand filling provides rapid arc cooling, preventing re-strike and ensuring a clean break.

Innovation Point 3: High Interrupting Capacity for Modern Power Systems
With a 200kA breaking capacity at 690V AC, the 170M5715 is engineered for modern high-power systems where available fault currents can exceed 100kA . This robust interrupting capability ensures that even under the worst-case short-circuit scenario—such as a full bridge arm shoot-through in a large inverter—the fuse will safely clear the fault without exploding or venting. This reliability is critical for safety, preventing arc flash events that could endanger personnel and damage adjacent equipment. The 170M5715 is certified to both IEC and UL standards, making it suitable for global projects .