for 644KW load which MCCB should i use

Answer Posted / antaratara ghosh

assuming the load as motor,operating voltage as 415 V,pf
as .85, efficiency as .95,

rated current, Ir= (644)/(1.732*0.415*0.85*0.95)
= 1110 A (approx)
now considering VFD starting for the motor,
starting current, Ist= 2*Ir
= 2220 A
considering margin of 20%, maximum current flowing =
2220*1.2 = 2664 A

Since MCCB are not used above 630 A in India, you have to
go for 3150 A (which is just greater than 2664 A and
available in market) ACB...

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