The function of a slow-blow fuse A slow-blow fuse is also called a time-delay fuse. Its time-delay characteristic is maintained in the circuit when it has a non-fault pulse current and can protect against prolonged overload. Some circuits have a current that is greater than a few times the normal operating current at the moment of switching on. Although this current pulse is very high, it occurs for a short time. We call it a pulse current or an inrush current or a surge. Ordinary fuses cannot withstand such currents. If such a circuit uses an ordinary fuse, it may not be able to start normally. If a larger fuse is used, it will not be protected when the circuit is overloaded. The melting of the time-delay fuse is specially processed to absorb energy. By adjusting the energy consumption, it can withstand the inrush current and protect against overload. 20 Pcs High-Quality Slow Blow Glass Fuses Fuse Dimension: 5x20mm/0.2x0.78 inch Fuse Current: 3.15A Fuse Volt: 250V Package Quantity: 20 Pcs Packed in a Plastic Storage Case