Fast Blow Fuse Vs Slow Blow Fuse

It has an element with a coiled construction and is designed to open only on a continued overload such as a short circuit.

Fast blow fuse vs slow blow fuse.

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. Fast acting fuses should be used in motor circuits will blow more frequently. A circuit designer would use a slow blow fuse when it is desired for a circuit to continue to work even after temporary spikes of current received such as a circuit being hit by lightning.

A slow blow fuse requires higher i2t than fast blow fuses to blow up. Many slow blow images here all glass ones that i looked at have spiraled wire. Typical slow blow fuse. But a slow blow one will melt its fuse wire after a specific period within 10 or 15 seconds.

Start by choosing a fuse rated to carry about 33 percent more than the expected load i e the normal current should be 75 percent of the expected load current then adjust for ambient temperature. The uses for a slow blow fuse and a fast blow fuse. The slow blow fuse has thermal inertia whereas a fast blow has a very short thermal time constant. How slow is slow enough.

By using a slow blow fuse you bypass this problem because as mentioned before. If it says f it means the fuse is a fast blow and if it says t or s it means it is a slow blow. Sometimes it is visually less apparent. A slow blow fuse though is constructed different internally.

For example if you send 40 amp current through a 30 amp fast blow fuse it will blow almost immediately. In general the time required for a fuse to blow can be given i2t where i is the current and t is the time. Here the coiled structure is clear. The types of fuses include long time lag or super time lag tt fast acting fuses ff quick blow fuses f and slow blow or time lag fuses t.

Selecting a fast blow fuse is fairly straightforward. The accumulated heat from adjacent sections helps blow the fuse. Other letters will indicate unique fuses for your specific device. Fuses at work a current can become corrupted or overloaded due to accidental damage from pets or being moved general deterioration excessive overloading of the electrical system or exposure to the elements.

A slow blow fuse is normally used in the motor industry because when you start an engine at that moment a high current of electricity is passed through the electronic circuit. Hence the fuses could be blown. It has a higher i2t value which means that it takes more energy to blow out than its fast acting counterpart with the same rating. 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.

For example assume a nominal load of 15 amps and an ambient.