What do you mean by Fuse and Circuit Breakers?

Contributed by:
kevin
A fuse is a safety device in an electric plug or circuit. It contains a piece of wire which melts when there is a fault so that the flow of electricity stops.
1. Vidhyadeep Institute Of Management & Technology, Anita, Kim
Electronics & Communication Department
V E
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IC A IC E
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EL Guided by Mr. Vicky Paperwala
2. Help to ensure safe and Prevents damage to an
healthy working electrical system.
conditions
Protective
Device
Protect from the risk It include circuit
of injury. breaker and fuse.
3. Protective Devices
1. Fuse
2. Circuit breaker
MCB
1.
MCCB
2.
ELCB
3.
4. FUSE
A type of low resistance
resistor to provide
overcurrent protection.
Prevents short-circuiting,
overloading, mismatched
loads or device failure.
5. FUSE CONSTRUCTION
The size and construction
of the element is
determined so that the
heat produced for a normal
current does not cause the
element to attain a high
6. HI L
TYPES OF
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C
VE
A
RF
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A
G
A
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FUSES
BE
GFL
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UE
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7. REWIREABLE TYPE
(SEMI ENCLOSED TYPE)
This kind of fuse is most
commonly used in the case
of domestic wiring and
small scale usage.
The main advantage of this type of
fuse is that it is easy to install and
also replace without risking any
electrical injury. But there are
certain shortcomings associated
with it too.
8. CARTRIDGE TYPE
TOTALLY ENCLOSED TYPE
The level of sub division in
this case includes:
1.D type
2.Link Type
Link type further divided into
1.Knife blade type HRC fuse
2.Botled type HRC link fuse
9. HIGH VOLTAGE FUSE
High-voltage fuses are used to
protect instrument transformers
used for electricity metering, or
for small power transformers
where the expense of a circuit
breaker is not warranted.
10. CIRCUIT
BREAKER
A circuit breaker is a manually or
automatically operated electric switch
designed to protect an electrical
circuit from damage caused by
overload or short circuit.
11. ELCB
A safety device used in electrical
installations with high earth
impedance to prevent shock.
A device used to directly detect
currents leaking to earth from an
installation and cut the power
and mainly used in TT earthing
There are two types of ELCBs:
1. Voltage Earth Leakage circuit
breaker (voltage-ELCB)
2. Current Earth Leakage Current
Earth Leakage Circuit Breaker
(Current-ELCB).
12. VOLTAGE - ELCB
A voltage-operated ELCB detects a
rise in potential between the
protected interconnected metalwork
(equipment frames, conduits,
enclosures) and a distant isolated
earth reference electrode.
Disadvantages of the voltage-
operated ELCB are the requirement
for a second connection, and the
possibility that any additional
connection to earth on the protected
system can disable the detector.
13. CURRENT ELCB
An electrical wiring device that
disconnects a circuit whenever it
detects that the electric current is not
balanced between the energized
conductor and the return neutral
14. VANTAGES AND DISADVANTAG
ELCBs have one advantage over
RCDs: they are less sensitive to fault
conditions, and therefore have fewer
nuisance trips.
1.As with RCDs, electrically leaky
appliances such as some water
heater, washing machine may cause
the ELCB to trip.
2.ELCBs introduce additional
resistance and an additional point of
failure into the earthing system
15. MCB
Miniature circuit breaker
It automatically switches off the electrical circuit during
abnormal condition of the network means in over load
condition as well as faulty condition.
MCB is much more sensitive to over current than fuse.
16. Miniature Circuit Breaker
Working Principle
There are two
arrangement of
operation of
circuit breaker.
1.One due to
thermal effect of
over current
effect of over
17. ADVANTAGES
1. It automatically switches off the
electrical circuit during abnormal
condition of the network means in
over load condition as well as faulty
2. Handling MCB is more electrically
safe than fuse.
3. Another advantage is, as the
switch operating knob comes at its off
position during tripping, the faulty
zone of the electrical circuit can
easily be identified.
18. COMPARISON
SR. PARTICULAR FUSE CIRCUIT BREAKER
1. FUNCTION PERFORMS DETECTION & PERFORMS
INTERRUPTION FUNCTION INTERRUPTON
2. OPERATION INHERENTLY COMPLETELY REQUIRES
AUTOMATIC ELABORATE
EQUIPMENT
3. BREAKING CAPACITY SMALL VERY LARGE
4. OPERATING TIME VERY SAMLL VERY LARGE
5. REPLACEMENT REQUIRES DOES NOT
REQUIRE
19.