Fast Blow Fuse Vs Slow Blow Fuse

Read the manufacturer s label if it says fast or slow the fuse type is as it is labeled.

Fast blow fuse vs slow blow fuse.

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. Other letters will indicate unique fuses for your specific device. In general the time required for a fuse to blow can be given i2t where i is the current and t is the time. Normally used for inductive loads like fans transformers etc.

For example assume a nominal load of 15 amps and an ambient. The uses for a slow blow fuse and a fast blow fuse. But a slow blow one will melt its fuse wire after a specific period within 10 or 15 seconds. The accumulated heat from adjacent sections helps blow the fuse.

Hence the fuses could be blown. 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. 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. 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.

Many slow blow images here all glass ones that i looked at have spiraled wire. Sometimes it is visually less apparent. Fast acting fuses should be used in motor circuits will blow more frequently. The slow blow fuse has thermal inertia whereas a fast blow has a very short thermal time constant.

It has an element with a coiled construction and is designed to open only on a continued overload such as a short circuit. A slow blow fuse though is constructed different internally. How slow is slow enough. In this article we will discuss fast blow fuse vs time delay fuse.

Slow blow fuse requires much higher time than the fast acting one. Selecting a fast blow fuse is fairly straightforward. 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. 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.

A slow blow fuse requires higher i2t than fast blow fuses to blow up. By using a slow blow fuse you bypass this problem because as mentioned before. Typical slow blow fuse. 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.

Here the coiled structure is clear.