MCCB - moulded case circuti breaker - its use for low
voltage applications
ACB - air circuit breaker - its use for extra high power
applications
VCB - vaccum circuit breaker - its use for UP to 33 KV
power applications
MCCB stands for Moulded Case Ckt Breaker.
ACB Air Ckt Breaker.
VCB Vaccume Ckt Breaker..Its to Simple yar....
Summary....
MCCB (Molded Case Circuit Breaker)—rated current up to 2500
A. Thermal or thermal-magnetic operation. Trip current may
be adjustable in larger ratings.
Vacuum circuit breakers are circuit breakers which are used
to protect medium and high voltage circuits from dangerous
electrical situations.
Air circuit breaker—Rated current up to 10,000 A. Trip
characteristics are often fully adjustable including
configurable trip thresholds and delays.
All the said breakers havet their own rupturing capacity (
ability to break the prospective short circuit level) and
are used accordingly.
MCB is Miniature Circuit Breaker which has a rupturing
capacity of 10KA and is used for lighting and other
circuits where the short circuit levels are below 10 KA
MCCBs or Moulded case circuit breakers have a rupturing
capacity of 80 KA
ACBs or Air circuit breakers have a rupturing capacity upto
120KA
VCBs are vacuum circuit breakers which are extensively used
in LV & HV circuits because of their advantages like a
longer operating life and lower erosion of contacts.
MCCB which is nothing but moulded case circuit breaker.
ACB is nothing but Air circuit breaker and Vcb is Vaccum
circuit breaker..The main difference between last two thing
is the arc quenching medium.ACB is air and VCB is
vaccum.these two things are used for power tr and
distribution and MCB,MCCBs are used in small rating
machines also...
mccb is moulded case circuit breaker, is used in power
cicuits to provide isolation for circuit from high current,
short circuit and earth fault. but mccb only can use in low
current cases at 440volts.
acb is air circuit breaker, can also use in power circuits
to provide isolation in those same cases. but in high
current cases at 440volts with more functions.
vcb is vaccume circuit breaker. it is for high voltage
cases like 11kv, 33kv etc with more function than acb and
same reason of application.
MCCB which is nothing but moulded case circuit breaker.
ACB is nothing but Air circuit breaker and Vcb is Vaccum
circuit breaker..The main difference between last two thing
is the arc quenching medium.ACB is air and VCB is
vaccum.these two things are used for power tr and
distribution and MCB,MCCBs are used in small rating
machines also...
All the above breakers are used for making and breaking an
electrical circuit under normal and abnormal(fault)
conditions.
The contact separation or travel in a MCCB takes place in a
moulded case and the maximum short circuit withstand
capacity of a MCCB is limited to 85 KA.
The contact separation in an ACB takes place in the medium
of air surrounding the contacts and in vacuum in VCB.
MCCB and ACB(125KA) are exclusively in low voltage
applications.
VCB can be used upto 36KV and its construction ensures the
following advantages over other types
1. It is more compact - smaller size
2, It has a smooth and quiet operation
3, It is echo-friendly - no gas or oil
4. least contact erosion leading to longer operating life
5. Minimum maintenance cost
MCCB,ACB,VCB all the three are protective devices only.
They are used to isolate the system which is connected
below them at fault conditions. Eg, Overload, Short
circuit,Earth fault.
MCCB - Operating on thermomagnetic principle, it's a very
compact taking less space can be used for low voltage 440
volts, up to 1000amps range.
ACB - Operating on electronic or microprocessor controller,
solenoid coil being used to isolate the system during fault,
it's takes more space as compered to MCCB & again it can
used for low voltage 440volts but up to 2500amps range.
VCB - Operating on electronic or microprocessor controller,
solenoid coil being used to isolate the system during fault,
it's takes more space as compered to MCCB & it can be used
for high voltage up to 33kv, above 33kv you go for SF6 breaker.
what is the role of impedance in transformer?based on
secondary f.l.current(139 amps) and impedance(4.07) of
415/415v of 100 kva transformer. what is the primary
current?
if only one generator is running in droop mode parrallel
with grid and suddenly grid breaker off what will happen?
It will trip o/u freq or stay as it is? (urgent)
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