Fast Blow Fuse Design

The slow blow fuse has thermal inertia whereas a fast blow has a very short thermal time constant.

Fast blow fuse design.

Hence the fuses could be blown. Fuse characteristics can be classified into three general categories. Many slow blow images here all glass ones that i looked at have spiraled wire. The time it takes for a fuse to blow either fast blow or slow blow is determined by the design of the fuse and is described in a table or graph provided by the manufacturer.

The distinguishing feature of slo blo fuses is that these fuses have additional thermal inertia. 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. Ul csa 248 14 compliant design ensures a low breaking capacity and thus offers immediate disconnect of power should the amperage exceed that of the fuse rating. Here the coiled structure is clear.

Sizing a fast blow fuse to allow the transients would result in a fuse which may not provide protection during some expected fault conditions. Other inferior fast acting fuses may vary by as many as 1 2 amps meaning your 8 amp fuse might not blow until power spikes to 10 amps. The uses for a slow blow fuse and a fast blow fuse. The accumulated heat from adjacent sections helps blow the fuse.

Time delay fuse and fast acting fuse a k a fast blow fuse are the most popular choice for electronic circuits like smps circuits or other power circuits. There are many types of fuse and we have already discussed them among them the slow blow fuse a k a. A fast blow fuse will open quickly before wires or traces or devices get too hot. In this article we will discuss fast blow fuse vs time delay fuse.

There s more to the current rating of a fuse than a single number. Sometimes it is visually less apparent. Very fast acting fast acting or slo blo fuse. Some fuses are intended to blow very fast while others are designed for more modest opening times or even for a delayed action.

This characteristic of a fuse design refers to how rapidly it responds to various current overloads. Yet a fast blow may be subject to nuisance failure due to momentary overload.