Bussmann Semiconductor Fuses

I2t coordination ensures fuse clearing I2t is less than semiconductor withstand I2t. Calculate fuse clearing I2t from curves at fault current. Semiconductor datasheet specifies withstand I2t. Select fuse with 20% margin below semiconductor rating.

Ensure fuse I2t < 0.8 x semiconductor withstand I2t.

Semiconductors are damaged by overcurrent much faster than wires or transformers. Standard fuses open too slowly to protect IGBTs and diodes. Semiconductor fuses clear in under 1ms to prevent thermal damage to expensive devices.

Always use high-speed semiconductor fuses for IGBT and diode protection.

I2t is the integral of current squared over time. Fuse datasheets provide clearing I2t at various voltages. Semiconductor datasheets specify maximum withstand I2t. Select fuse with clearing I2t less than 80% of semiconductor rating.

Use manufacturer coordination tools or consult our FAE for I2t calculations.

For 690V AC systems, select 700V or higher rated fuses. For 690V DC systems, consider 1000V rated fuses to account for DC reversal and transients. Always include voltage margin. For more detailed information and application guidance, please consult the product datasheet or contact our technical support team.

Select fuse voltage rating at least 20% above maximum circuit voltage.

While possible, semiconductor fuses are optimized for fast clearing and may nuisance open on transformer inrush or motor starting. For general circuits, use Class J or RK fuses which are more economical.

Use semiconductor fuses only for semiconductor protection. Use standard fuses for general circuits.