While starting a high capacity motor, it takes 6 times the full load current.

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?

Question Posted / edisondasan

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While starting a high capacity motor, it takes 6 times the full load current. Why it doesn't..

Answer / a.alexander

Motor Current will take 6 to 7 times for Just 3 to 6 Sec
only. and Cb was with stand the Current in Same Seconds
.That is Set point of CB full load Current.

Is This Answer Correct ?

12 Yes

4 No

While starting a high capacity motor, it takes 6 times the full load current. Why it doesn't..

Answer / 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.

Is This Answer Correct ?

7 Yes

0 No

While starting a high capacity motor, it takes 6 times the full load current. Why it doesn't..

Answer / praful nandankar

Circuit breakers are given sufficient delay time,hence the
relay will not trip when motor takes 6 times the full load
current.

praful nandankar

Is This Answer Correct ?

1 Yes

1 No

While starting a high capacity motor, it takes 6 times the full load current. Why it doesn't..

Answer / sunthosh080

usually when you see the relay technical details there will
CLASS type (5-30)

When your motor is taking 6 times for 5 sec you have to
select 5. So that your relay doesnt trip during this and it
depends on the application also.

If it fan application , then it would be around 15-20.

If the relay is tripping during motor starting then it
CLASS problem.

Is This Answer Correct ?

0 Yes

4 No

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