how to select short circuit current while selecting a MCCB?
how to calculate current for a given KVA and KW load?

Answer Posted / john

FOR A 1000KVA TRANSFORMER.
PRIMARY VOLTAGE=15000V=15KV
SECONDARY VOLTAGE=480V=.48KV
impedence =5.75%
short circuit current at primary=1000/15*1.73*.0575=670amps.
short circuit current at
secondary=1000/.48*1.73*.0575=20943amps.

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