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While starting a high capacity motor, it takes 6 times the
full load current. Why it doesn't trip relay or CB's in
that network?
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Answer Posted / blake_australia
The starting current for an induction motor is around 6x
full load current, however this is only for ~3cycles. Which
is about 0.06seconds (for 50Hz power).
Circuit breakers chosen for motors (D curve in Australia)
delay for more than this 0.06seconds. The curves can be
seen in any NHP breaker selection catalog. Protection
curves are more indepth than this, reading into these will
help.
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