Answer / chintan patel

It can be different for DC , 1phase AC , 3 phase AC , systems,

Lets calculate for all ,

1 ) For DC ( you have not mentioned Voltage but considering 230 V )

100 kw means 100000 watt

formula for DC power p= vi

100000= 230xi

i=100000/230= 434 amp

we always use current rating of the mccb is 1.5 times of full load current so we can use 434x1.5= 652 amp.
( if system is not running on full load select 630 Amp MCCB, if its on full load select 800A )


2 ) For 1phase AC,

Power: P = V I cos phi ( cos phi is power factor is not known assume 0.8 )

100000 W = 230 x I x 0.8
I = 543 Amp

we always use current rating of the mccb is 1.5 times of
full load current.
mccb required 543 Amp X 1.5 = 815 Amp
select 800 Amp MCCB

3)

If load is 3 phase AC ,

Power P = sqrt(3) x V x I x cos phi

100000 w = 1.73 x 415 x I x 0.8
I = 174

we always use current rating of the mccb is 1.5 times of
full load current.
mccb required 174 Amp X 1.5 = 261 Amp

( if system is not running on full load select 250 Amp MCCB,
if its on full load select 315 A )

Answer / kalyan sharma

for 100 kw we will use 3 phase supply inplace of single
phase.

use formula p= 1.732 vi cosphi

100= 1.732*0.415*0.8*I

I = 174 amp

we always use current rating of the mccb is 1.5 times of
full load current so we can use 250 AMPs MCCB.3P/4P.

Answer / rajat

for 100 kw means 100000watt

use formula p= vi

100000= 230xi

i=100000/230= 430 amp

we always use current rating of the mccb is 1.5 times of full load current so we can use 430x1.5= 645 amp

Answer / r g walia

for 100kw load required 630 amp mccb will be used.

Answer / siddhart jha

mccb of 250 A/440V MUST BE USED FOR THAT.

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