UST 1206 SMD Fuses Schurter UST 1206 SMD Fuses are UL 248-14 rated and Time-Lag T characteristic fuses. These fuses offer high melting I2t-values and up to 25A high current ratings. The UST 1206 fuses are impermeable to the porting compound. These Schurter fuses operate at 32VAC or 63VDC rated voltages and 100A to 600A breaking capacity. Typical applications include secondary protection DC and AC circuits with inrush and LCD backlight DC-AC inverters.