(Branch: Civil Engineering)

1)Haresh I Bharadiya (130680106002)

2)Lalabhai N Vagh (130680106048)

3)Nikunj P Patel (130680106027)

• It is the simplest form of protection Against excess current, Short circuit and earth fault.

• A fuse is a Wire or strip of metal of short length having low melting point.

•The fuse wire is held in porcelain fuse carrier and inserted in series with an electric circuit as a protective device in abnormal Condition.

There Are many types of Fuses like,

1)Kit-kat type of fuse

2)Cartridge type of fuse

3)H.R.C type of fuse

This is commonaly used in House wiring.It is made of porcelain in two parts i.e base and a fuse carrier.The base is with switch board.

The phase or incoming wire is inserted from one side and connected to the terminal.

Onward connection is taken from the other terminal known as out going terminal.

Advantages:-

Easy removable and replacement of fuse at negligible cost.

Disadvantages:-Every possibility of rewiring by a wrong size or improper material wire.They have low breaking capacity, can not be used for too high currents.

The fuse wire can deteriorate over a period of time due to oxidation through continuous heating of the fuse element.

This is a totally enclosed type fuse unit. It is enclosed in an insulating container of tube shape. The container the fuse wire is filled up with powder and sealed at its ends with metallic.

The power provides good insulating path for the fuse and helps to absorb the arc at the time of blowing up of fuse. It is not very economical.

It is generally used at 415 V supply system.

With a heavy load capacities of the distribution network extremely heavy currents would flow into the fault and the fuse clearing the fault would be required to withstand heavy stress in the process.

H.R.C cartridge fuses are therefore used for such duties and these are specially designed for extremely rapid operation.

HRC fuses are also designed to absorb rapid heat produced by are formed at the time of blowing out.

The rating is much more accurate and are particularly suited for breaking much heavier currents safely.

Advantage and disadvantage of various type of fuse:-

Advantages:-Most reliable to withstand heavy as well as low stress in clearing the fault.

Low temperature rise at full load.

Silent operation and non-deteriorating feature.Maintenance is not required.

Operation is quick, sure and reliable.

Disadvantages:-

Advantage and disadvantage of various type of fuse:-

Most uneconomical.

Little difficult to ascertain which of the fuse has blown.