Recent content by sameee781

In our country phase voltage is 230v but in worse case it may goes below 200v. Sometimes during irrigation period, water pump motor burnt out. Of course current increases with the decrease of terminal voltage. I wanted to know the rating of safest CB to avoid this case.

No I'm not in USA. I'm in Bangladesh. In our country voltage is 230v with frequency 50Hz. Motor is rated in hp.

Thanks... Now, my question is Why CB would be 250% of full load current? Usually, do the CBs not allow 3 to 5 time of rated current?

P=5hp=746*5w=3730w V=230v I=P/V=3730/(230*0.75)=21.6A [where pf=0.75] How the full load current of this motor be 28A? Why CB would be 250% of full load current? Usually, do the CBs not allow 3 to 5 time of rated current?

How can I chose proper circuit breaker to be used in a single phase induction motor? Example case: Power: 5hp Voltage: 230v AC