Mersen A070UD32LI350 Protistor Fuse, 350A 700V AC, Size 32 aR, High-Speed Square Body with LI Bolted Contacts - Pack of 3

The Mersen Protistor® A070UD32LI350 (Item Number X219775) is an ultra-fast acting square body fuse-link designed for the high-performance protection of power semiconductor devices. Rated at 350A and 700V AC, this Size 32 aR class fuse is engineered for industrial applications requiring rigorous protection against overcurrent, such as semiconductor rectifiers, DC drives, and UPS systems. It is characterized by its ability to provide extremely low let-through energy (I²t) and excellent peak current limitation, effectively shielding sensitive electronics like thyristors and diodes from fault damage.

The fuse construction features a durable ceramic body and silver-plated copper LI-style bolted blade contacts, ensuring low power loss and high mechanical stability. Its internal architecture utilizes pure silver elements and high-purity silica sand for superior arc quenching, supporting a high breaking capacity of 200kA. This model comes integrated with a Type K mechanical striker, providing a reliable visual indication of fuse operation and the option to trigger remote monitoring through an auxiliary microswitch.

Technical Specifications

• Manufacturer: Mersen
• Catalog Number: A070UD32LI350
• Item Number: X219775
• Amperage Rating: 350A
• 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: LI (Bolted Blades)
• Indication System: Integrated Mechanical Striker (K-Type)
• Pre-arcing I²t: 14.5 kA²s
• Total Clearing I²t at Rated Voltage: 97 kA²s
• Power Dissipation at Rated Current: 65W
• Standards Compliance: IEC 60269-4, UL 248-13 Recognized, RoHS Compliant
• Quantity: Pack of 3