We use MCCB not MCB for motor starters because MCCBs has capablity to drawout th

We use MCCB not MCB for motor starters because MCCBs has capablity to drawout the motor starting current which is 5-6 times the full load current of motor for 1sec.
Then why we use SDF in starter panel means MCC panels.
Pls reply if any one knows this answer.

Question Posted / rajusawant

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We use MCCB not MCB for motor starters because MCCBs has capablity to drawout the motor starting cur..

Answer / omer a.osman

What do you mean by SDF. I guess Star/Delta.
In this case, the starting current will be reduced & within 15 to 20 Sec. the Sytem will changed to Direct on line in running Condition by taking the full load current. Hence, the recommended MCCB rating as protective device to protect the feeders should not be less than the current carrying capacity & tripping current about 1.45In. However, the breaking Capacity of the MCCB is an essential factor.

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