Bussmann 170M6743 Class aR Square Body High-Speed Fuse, 550A

Bussmann 170M6743 Class aR Square Body High-Speed Fuse, 550A

The Bussmann 170M6743 is a Class aR square body high-speed fuse rated 550A RMS, engineered for demanding semiconductor and power electronics protection where fast clearing and high interrupting capacity are critical. With a 100 kAIC interrupt rating and clearing I²t of 325,000 A²s at 1000V and 435,000 A²s at 1250V, this fuse delivers coordinated overcurrent protection for DC common bus systems, DC drives, power converters/rectifiers, and reduced voltage starters. Its square body US-style construction with -FKE/115 type K indicator supports micro-switch monitoring, and the non-indicating design keeps the footprint compact for panel layouts.

Key Features

• Current Rating: 550A RMS for reliable protection of high-current DC bus and drive circuits.
• Fuse Class: Class aR high-speed fuse construction for semiconductor and power converter protection.
• Interrupt Rating: 100 kAIC for dependable performance under high fault-current conditions.
• Clearing I²t: 325,000 A²s at 1000V and 435,000 A²s at 1250V for coordinated protection.
• Pre-Arc I²t: 55,000 A²s for predictable time-current response.
• Fuse Indicator: Non-indicating design for a compact fuse body.
• Watt Losses: 110W rated power dissipation.
• Construction: Square body US style with -FKE/115 type K indicator for micro-switch compatibility.

Certifications & Compliance

• CE Marked
• RoHS Compliant
• IEC Rated
• CSA Certified
• UL Recognized

Technical Specifications

• Amperage Rating: 550A
• Current Rating: 550A RMS
• Class: Class aR
• Application: DC common bus, DC drives, power converters/rectifiers, reduced voltage starters
• Clearing I²t: Clearing at 1000V: 325000, Clearing at 1250V: 435000
• Pre Arc I²t: 55000
• Interrupt Rating: 100 kAIC
• Fuse Indicator: Non Indicating
• Watt Losses: 110W
• Packaging Type: Standard
• Product Type: Square body US style, -FKE/115 type K indicator for micro
• Product Details: Square body US style, -FKE/115 type K indicator for micro
• Product Length: 5.433 IN
• Product Height: 2.087 IN
• Product Width: .315 IN
• Product Weight: 1.6456 LB

Typical Applications

• DC Common Bus Protection
• DC Drive Systems
• Power Converters and Rectifiers
• Reduced Voltage Starters
• Industrial Power Electronics Protection

Why Bussmann?

Bussmann high-speed fuses are built for the demanding protection requirements of semiconductor and power conversion equipment, combining a 100 kAIC interrupt rating with engineered clearing and pre-arc I²t characteristics for coordinated circuit protection. Backed by CE marking, RoHS compliance, IEC rating, CSA certification, and UL recognition, the 170M6743 delivers code-compliant, dependable performance for DC bus, drive, and converter applications.