How you calculating the current for a 2.5 Sqmm cable.
A 30 Hp 3 phase AC motor of power what size of cable is
used for this motor.


Answer Posted / balakrishnan.t

For calculating the current rating of a 30 Hp 3 phase motor can be written as
power = sq root(3)* VL*IL*cos (phi)--------(1)
where 'VL' is line voltage, 'IL' - line current and cos phi- power factor

OR 3 EP*IP*cos(phi)
as the voltage fed is from three phase system.
Power input of 30 Hp motor = 30*746/(efiiciency*cos phi) watts
from the formula (1) and taking efficiency as 0.9,
Line current 'IL' = 30*746/(1.732*415*0.9*0.83)
= 41.68 Amps

Is This Answer Correct ?    6 Yes 3 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

i want to model paper for section engg.

1573


how to find number of run cable laying[LT side] for transformer & alternator secondary side? [above condition for getting output power transformer to main panel side] give the example.

1603


what are the main applications of transistor in non-linear region?

1454


What are the advantages and disadvantages of closed-loop control system?

711


How delta connection in the primary of distribution transformer reduces harmonics?how delta connections reduces harmonics?Please answer me...Hope that question is correct.

1734






What is an Air COmpressor

1727


What is the fault or needs to be done when frequency in ac drives is not changing?

1210


what is the difference between dry and wet type of 132kV terminations. which one is durable

1558


How will A Medium voltage circuit breaker(11 kV voltage level) operate under short circuit fault condition whether It is having short circuit release like Low voltage circuit breaker or relay should be given?

1433


bsec exam syllabus (mis)

737


in cvt,there are two windings,1a,1n and 2a,2n.in my one project i use only one winding i.e.1a,1n. the other winding is not in use, so i connect it in open delta and want to close it by ibsertibg thermal resistor. the output of cvt is 132kv/115/sqrt3. plesae tell me exact value of resistor, so i may close it to avoid the resonance phenomenin. send me answer on this email adress please. aetcon-po@aetcon.com

2165


HOW TO CHECK THE VECTOR GROUP OF A TRANSFORMER YD11?

3155


how is calculated the quantity of weight in hot test xlpe?

2014


what do u understand from filter factor of reactor?

1536


Draw the line diagram of diffretial relay connected to transformer?

1971