Mersen A070UD32KI900 Protistor Fuse, 900A 700V AC, Size 32 aR, High-Speed Square Body with KI Bolted Contacts - Pack of 3

The Mersen Protistor® A070UD32KI900 (Item Number P300198) is a premium ultra-fast acting square body fuse-link developed specifically for the protection of power semiconductors. With a robust current rating of 900A and a 700V AC capacity, this Size 32 aR class fuse is a critical component in high-power industrial systems, including semiconductor rectifiers, DC drives, and large-scale power converters. It is engineered to minimize let-through energy (I²t) and provide elite peak current limitation, preventing catastrophic damage to sensitive electronic components like thyristors and IGBTs.

Constructed with a high-grade ceramic housing and silver-plated copper KI-style bolted terminal blades (Metric Bolted Studs), the fuse ensures low contact resistance and high thermal stability. The internal design leverages pure silver elements and high-purity silica sand for extremely fast arc quenching, achieving a high breaking capacity of 200kA. This model includes an integrated Type K striker, offering a mechanical visual indication of fuse operation and the capability to trigger remote monitoring microswitches.

Technical Specifications

• Manufacturer: Mersen
• Catalog Number: A070UD32KI900
• Item Number: P300198
• Amperage Rating: 900A
• Voltage Rating: 700V AC (IEC / UL)
• Interrupting Rating (Breaking Capacity): 200kA at 700V AC
• Operating Class: aR (Ultra-Fast Acting)
• Product Size: 32
• Mounting Configuration: KI (Metric Bolted Studs)
• Indication System: Integrated Mechanical Striker (K-Type)
• Pre-arcing I²t: 255 kA²s
• Total Clearing I²t at Rated Voltage: 1700 kA²s
• Power Dissipation at Rated Current: 130W
• Standards Compliance: IEC 60269-4, UL 248-13 Recognized, RoHS Compliant
• Quantity: Pack of 3