Answer / mohd mansoor

The diferece is all about their arc quenching medium

MCCB-moulded case circuit breaker ..here arc is quenched by
the special designed case of switchgear

ACB-Air circuit breaker ..here arc is quenched in a medium
by the force of air

VCB..(Vaccum Circuit Breaker)...here arc is quenched in
vaccum medium

And their use depends upon the amount of current to be
isolated ...Like ACB is used where the load current is more
then 1000A..MCCB is used in a range from (63A to 800A) and
VCB is generally used at HT side

Answer / muthukumar

im not having much idea in MCCB but i have idea in ACB and
VCB. ACB used in low voltages like 415V, 440V Etc but VCB
used in high voltages like 11KV but both are used for arc
absorbing or reducing the arc formation when the circuit is
closed or get any damage.VCB interrupt the arc via the arc
interrupter which was placed inside the VCB. the arc
interrupter is full of vaccum only. by using this vaccum
arc is interrupted. ACB interrupt the arc via air.

Answer / eng. moaz rabah

MCCB protecting from

1. Short Circuit (SC)
2. Overload (OL)



ACB protects from

1.SC
2.OL
3.Over voltage
4.Under voltage
5.Earthing
6.Reverse Current Flow

imagine u have deffect in the transformer, some short
happened in the primary that means all the 11KV will be
connected to MD designed only for 415v, then the ACB can
obserb that over volt but the MCCB will burn

Answer / ajaykumar

in industries where there are so many machines work
simultaneously. if fault occurs on any one machine then air
circuit breaker or vcb which is connected to the supply side
will get trip. because of one machine other machines supply
will get intertupte. to prevent this :
mccb is connected in series with each machine so that if
fault occurs on one machine others machines will not get
affecetd. and air circuit breaker which is connected to
supply side will not get trip.
current rating is the not only difference between acb and
mmcb.

Answer / sri

MCCB - MOULDED CASE CIRCUIT BREAKER
ACB - AIR CIRCUIT BREAKER.
VCB - VACCUM CIRCUIT BREAKER

MCCB can be used in the saftey of machines for LT side with
higher Amps ratings i.e.. upto 250Amps.

But ACB and VCB are used in the HT side only.
But all the three are used for short circuit trippin and
fault tripping.

ACB and VCB are highly sensitive and based on various
factors like Milliamps setting,Short circuit time etc..

Answer / anand kumar shukla

according to my knoweldge the difference between mccb,
Acb, Vcb is depending on the fault interruption capacity
and rating of voltage and current level.
mccb-250amp
acb-1650 amp
vcb -up to 11 kv and up to 1650amp.

Answer / salil ahmad ansari

MCCB-Moulded case circuit breaker
ACB-Air circuit breaker
VCB-Versatrip circuit breaker

What is the Procedure for selecting a Cable, Breaker and Transformer for particular load.

3 Answers  

how we can check that any motor is faulty may be single phase or three phase?

2 Answers   MAHINDRA,

why we use ac system in india why not dc

3 Answers  

Whether 3 phase induction motorwith 100 hp capacity , Amp 160 for which sensitive earth fault relay , type CTUM 15 can be used?

0 Answers   ONGC,

what is the voltage rating of chiller unit sensors

0 Answers   Voltas,

what is the RMU and RMU system in sub-station(11kv,66kv.....)

2 Answers   Alstom, Torrent Power,

How will you determine the rating of a motor for continuous duty variable load motor applications?

1 Answers  

Can you use step up generator transformer of voltage ratio 16.5kv/420kv in place of step up generator transformer 15.75kv / 420 kv

1 Answers  

can we connect transformer with star conected secondary to delta connected primary in series?

1 Answers  

when we design electrical schemes of 11/.415kv distribution..wen and were should we show the relays??what is the function of it?for example..we place EFR Relay CT between transformer neutral link and transformer earth.Like this what are the other type of relays we should use?why?where?Explain please..Thank you

0 Answers   ETA,

What is RMU, and what it's function?

2 Answers  

why are using bus ducts ? why not using cables

12 Answers