fuse and mcb 2

8/10/2019 FUSE AND MCB 2

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HISTORY

The genesis of Escorts goes back to 1944 when two brothers, Mr. H. P. Nanda and Mr.

Yudi Nanda, launched a small agency house, Escorts Agents Ltd. in Lahore. Over the

years, Escorts has surged ahead and evolved into one of India's largest

conglomerates. In this journey of six decades, Escorts has had the privilege of being

associated with some of the world leaders in the engineering manufacturing spacelike Minneapolis Moline, Massey Ferguson, Goetze, Mahle, URSUS, CEKOP, Ford

Motor Company, J C Bamford Excavators, Yamaha, Claas, Carraro, Lucky Goldstar, First

Pacific Company, Hughes Communications, Jeumont Schneider, Dynapac . These

valued relationships be it technological or marketing, are our highly cherished

experiences treasures, which have helped us inculcate best in class manufacturing

practices and to emerge as a technologically independent world class engineeringorganization.


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POWERTRAC& FARMTRAC

Powertrac series from Escorts Ltd. has been engineered with the use of the most

modern technology to redefine power and performance. The series has a wide

range of tractors with powerful engines and pollution norms.

Powertrac series comprises of tractors with transmission choices, powerful PTO,

advance hydraulics and ergonomic design besides other salient features


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BACKGROUND

In 1960, Escorts set up the strategic Agri Machinery Group (AMG) to venture into tractors.

In 1965, we rolled out our first batch of tractors under the brand name of Escort.

In 1969 a separate company, Escorts Tractors Ltd., was established with equity participation

of Ford Motor Co., Basildon, UK for the manufacture of Ford agricultural tractors in India.

In the year 1996 Escorts Tractors Ltd. formally merged with the parent company, Escorts

Ltd.

Since inception, we have manufactured over 1 million tractors.


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GROUP

The Escorts Group, is among India's leading engineering conglomeratesoperating in the high growth sectors of agri-machinery, construction &

material handling equipment, railway equipment and auto components.

Having pioneered farm mechanization in the country, Escorts has played a

pivotal role in the agricultural growth of India for over five decades. One of the

leading tractor manufacturers of the country, Escorts offers a comprehensiverange of tractors, more than 45 variants starting from 25 to 80 HP. Escort,

Farmtrac and Powertrac are the widely accepted and preferred brands of

tractors from the house of Escorts.

A leading material handling and construction equipment manufacturer, we

manufacture and market a diverse range of equipment like cranes, loaders,

vibratory rollers and forklifts. Escorts today is the world's largest Pick 'n' Carry

Hydraulic Mobile Crane manufacturer.
http://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.html


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Mr. Rajan Nanda

Chairman

Mr. Nikhil Nanda

Joint Managing Director

Mr. Rohtash Mal

ED & CEOAgri Machinery Group

Mr. Kanwal Kishore VijED & CEOEscorts Construction Equipment Limited (ECEL)

Mr. Vikram Singhal

ED & Business HeadEngineering Division

Mr. G.B. Mathur

EVPLaw & Company Secretary

Mr. O K Balraj

EVP & Group CFO

Mr. Ishan Mehta

EVP

HR & ER

BOARD OF DIRECTORS
http://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.htmlhttp://www.escortsgroup.com/the_group/group_leadership_team.html


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Introduction to fuse Construction of fuse

Types of fuse Working of fuse

Introduction to mcb Parts of mcb

Difference between mcband fuse

concluding videos

Topics


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NEED OF FUSE

In any electric installation, if the metallic partof the electric appliance such as the metallic

frame, metal covering of cables etc. comes indirect contact with a live wire, the metal willbegin to get charged since it is a goodconductor of electricity .

If a person comes in contact with the metallicpart then he will get a shock. so, to save theperson from the shock we need fuse and mcb.


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INTRODUCTION OF FUSE

The basic purpose of the fuse is to protectelectrical appliance and is composed of analloy which has a low melting point. A stripof this fuse is placed in series with the circuit.

The working principle is that if the current isin excess then the strip would melt and breakthe circuit.


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In electronics and electrical engineering,

a fuse (from the French fuser, Italian fuso,"spindle") is a type of low resistance resistor thatacts as a sacrificial device to provide over

current protection, of either the load or sourcecircuit.

Its essential component is a metal wire or stripthat melts when too much current flows, which

interrupts the circuit in which it isconnected. Short circuit, overloading,mismatched loads or device failure are the

prime reasons for excessive current.


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CONSTRUCTION OF FUSE

The main components of astandard fuse unit consist ofthe following items:

I. Metal fuse elementII. Set of contacts

III. Support body

IV. Connection


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The fuse element is made of zinc, copper, silver,aluminum, or alloys to provide stable and predictablecharacteristics.

The fuse element may be surrounded by air, or bymaterials intended to speed the quenching of thearc. Silica sand or non-conducting liquids may beused.

The fuse also consists of other components like Triggerassembly spring , Heat absorber.


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Types offuse

Low voltagefuse

Rewireablefuse

Cartridgefuse

Highvoltage fuse


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REWIREABLE FUSE

This kind of fuse is most commonly usedin the case of domestic wiring and smallscale usage. Another name for this type is the

KIT-KAT type fuse. The main composition isof a porcelain base which holds the wires.

The main advantage of this type of fuse isthat it is easy to install and also replace

without risking any electrical injury.When there is an over surge that causes thefuse element to blow off, you can replace it. Anew fuse carrier is inserted in the base.


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CARTRIDGE FUSE

In this type of fuse, we have a completelyclosed container and there are contacts(metal) on either side. The level of subdivision in this case includes:

I. D typeII. Link Type

Link type fuses: In Link type, we further

have a knife blade type and a bolted type.D Type Fuses: This cannot be interchanged

and comes with the following maincomponents: fuse base and cap, adapter

ring and the cartridge.


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HIGH VOLTAGE FUSE

Fuses are used on power systems up to 115,000 voltsAC. High-voltage fuses are used to protect instrumentlike transformers used for electricity metering, or forsmall power transformers where the expense of

a circuit. They are used in power supply networks and for

distribution uses. The most frequent application is intransformer circuits, with further uses in motor

circuits and capacitor banks.High-power fusemeans that these fuses can interrupt

several kilo amperes. Some manufacturers have testedtheir fuses for up to 63 kA cut-off current.
http://en.wikipedia.org/wiki/Circuit_breakerhttp://en.wikipedia.org/wiki/Circuit_breaker


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WORKING OF FUSE

Fuse will melt when the current exceeds its maximumcurrent rating. By melting , the fuse thus destroys aportion of the conducting path. This stops the currentfrom flowing in the rest of the circuit.

When the fuse melt, the fuse element absorbs someenergy. This energy is given by I2t where I is peak valueof current interrupted and t is the time taken to clearthe fault.

When the fuse blows , it gives an indication that thereis some mal functioning in the circuit.


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VIDEO SHOWING

FUNCTIONING OF FUSE


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INTRODUCTION OF

MCB

A Miniature circuit breaker is a manually orautomatically operated electrical switch designed

to protect an electrical circuit from damage causedby overload or short circuit.

Its basic function is to detect a fault condition andinterrupt current f low.

Unlike a fuse, which operates once and then mustbe replaced, a circuit breaker can be reset (eithermanually or automatically) to resume normaloperation.


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Circuit breakers are made in varyingsizes, from small devices that protectan individual household applianceup to large switchgear designed toprotect high voltage circuits feeding

an entire city.


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SYMBOL OF MCB

Miniature circuit = switch + trip unit breaker (MCB)


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DIMENSION OF MCB

45

maxi

10 maxi60

35

81

44 maxi

21.3

symmetricalrail external

partdepth

width


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PARTS OF MINIATURE CIRCUIT

BREAKERS

A

C60N NC100 / NC125

terminalfixed contact

movingcontact

strip braid

magnetictrip

load sideterminal

terminalbimetral strip

strip braid

movingcontact

magnetic trip

load sideterminal

strip braidbimetal strip


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OVERLOAD PROTECTION

Current Limiting Breakers use anelectromechanical (Thermal /Magnetic) trip unitto open the breaker contacts during a over current

event. The thermal trip unit is temperaturesensitive and the magnetic trip unit is currentsensitive. Both units act independently andmechanically with the breakerstrip mechanism to

open the breakerscontacts. MCB miniature circuit breakers instantaneous

trip unit interrupts a short circuit in 2.3 to 2.5milliseconds, and stops the flow of current


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Thermal Trip Unit

The thermal trip unit protects against acontinuous overload. The thermal unit iscomprised of a bimetal element located behindthe circuit breaker trip bar and is part of thebreakerscurrent carrying path.

When there is an overload, the increased current flow heats the bimetal causing it to bend. As the

bimetal bends it pulls the trip bar which opens thebreakerscontacts.


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The time required for the

bimetal to bend and trip thebreaker varies inversely withthe current. Because of this, thetripping time becomes quicker

as current increases inmagnitude . Overloadprotection is applicable to anyinstallation, conductor, or

component which can besubjected to low-magnitudebut longtime over currents


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Current Flowing Through MCB


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Magnetic trip unit

The Magnetic trip unit protects against a short circuit.

The magnetic trip unit is comprised of anelectromagnet and an armature. When there is a shortcircuit, a high magnitude of current passes throughthe coils creating a magnetic field that attracts themovable armature towards the fixed armature. Thehammer trip is pushed against the movable contactand the contacts are opened. The opening of thebreakers contacts during a short circuit is complete in.5 milli-seconds.


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Magnetic trip unit


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Arc runners Arc chutes

The arc runner and arc chute limit and dissipate thearc energy during the interruption of an overload orshort circuit event.

During an overload or short circuit event, the contactsof the breaker separate and an electrical arc is formedbetween the contacts through air.

The arc is moved into the arch chute by runningthearc down the interior of the breaker along the arcrunner. When the arc reaches the arc chute it is brokeninto small segmented arcs.


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COMPARISION BETWEEN MCB AND FUSE

MCB FUSEMCB trips off in case of excessiveload.

MCB is to be just put-on aftercorrecting the fault in wiringSince we do not change the MCB,there is no risk of putting on theMCB/switch even if the fault is not

correctly repaired.Compact, small equipment.Works on Bi-metal expansion orinduced magnetism.Relatively costlier than fuse.

Fuse melts/fuses in case of excessiveload.

Fuse needs to be replaced with a newone.There is a risk of putting on theswitch in case; due to ignorancehigher capacity fuse-wire is

positioned.It has Porcelain base and top1`Works on melting/fusing due to hightemperature.Relatively cheaper than MCB.


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BIBLIOGRAPHY

ELEMENTS OF ELECTRICAL ENGINEERING

(J.N SWAMY AND N.V SINHA)

INFORMATION FROM:-WIKIPEDIA

ABBWORKS

PICTURES FROM :-

GOOGLE


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fuse and mcb 2

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