Fast Blow Fuse Time

For example if you send 40 amp current through a 30 amp fast blow fuse it will blow almost immediately.

Fast blow fuse time.

Slow blow fuse requires much higher time than the fast acting one. In this article we will discuss fast blow fuse vs time delay fuse. In general the time required for a fuse to blow can be given i2t where i is the current and t is the time. Fast acting fuses should be used in motor circuits will blow more frequently.

A time delay fuse also known as an anti surge or slow blow fuse is designed to allow a current which is above the rated value of the fuse to flow for a short period of time without the fuse blowing. The uses for a slow blow fuse and a fast blow fuse. But not all surges are the same and not all time delay fuses are the same. Examples if a circuit has a current rating of 15 amperes and a voltage rating of 120 volts then the current rating should not exceed 15 amperes and the voltage rating should be at least 120 volts.

But a slow blow one will melt its fuse wire after a specific period within 10 or 15 seconds. Hence the fuses could be blown. The question is how to match the fuse to the load. Normal fast blow fuses are the most general purpose fuses.

Many people think that time delay fuses are less effective because they allow current overloads pass through the circuits. A slow blow fuse requires higher i2t than fast blow fuses to blow up.