18-08-2012, 09:56 AM
Seminar on FUSES
FUSES.pptx (Size: 510.01 KB / Downloads: 183)
INTRODUCTION
This presentation discuses about fuses, how it works, its design and how it will effects the electric circuits around us .
What is fuse?
In electrical and electronics engineering a fuse is a type of sacrificial overcurrent protection device.
Its essential component is a metallic strip which melts as excess current flows through it.
PACKAGES AND MATERIAL
Fuse consist of two main parts:
Fuse casing
Fuse elements
Fuse casing may be made up of:
Ceramics
Glass
Plastic
Molded mica laminates
FUSE- WORKING
A fuse has a metallic strip of small cross section area , mounted between a pair of electrical terminal.
The fuse is connected in series with the circuit through which all the current will pass.
In case of heavy current, fuse will melt. This will break the circuits and protect the electrical appliance.
CHARACTERISTIC PARAMETER
Rated current
Maximum current that a fuse can bear without interrupting the circuit .
Speed
speed at which fuse blows depends on the amount of current passing through it .
Based on speed blow can be of 3 types
Normal blow
Fast blow
Slow blow
FUSE MARKINGS
Most fuses are marked on the body or on the end caps , with marking representing their rated value.
Fuse marking will convey the following information:
Ampere rating
Voltage rating
Breaking capacity
Time current characteristic
Approval by international standard agencies
Coordination of fuses in series
All fuses are connected in series at various level of power distribution system.
It will blow the fuse nearest to the fault.
In this case only faulty circuit is interrupted with minimal disturbance to the other circuits.