Follow Our FB Page << CircleMedia.in >> for Daily Laughter. We Post Funny, Viral, Comedy Videos, Memes, Vines...


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.


Answers were Sorted based on User's Feedback



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

Answer / shoyabkhan

the answer is wrong we can calculate by usbing this formula
W = 1.732*V * I Cos (phi)
30*746 = 415 * I * 0.8*1.732
I=36.2 AMP

Is This Answer Correct ?    24 Yes 6 No

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

Answer / shashank

deciding a cable has to consider following parameters also,
1. Safety factor of the cable (margin for starting current
say 1.25 in numerator side)
2. Deterioration / Degradation factor (say 0.8 in
denominator)
calculate the current of the motor by considering running
pf (power factor) say 0.8
as motor gives real power
e.g.
W = V * I Cos (phi)
30*746 = 415 * I * 0.8
I = 30 * 746 / (415*0.8)
I = 67.41 Amp,
Thus Current considered for cable (Icb) = 67.41*1.25/0.8
Icb = 105.3 Amps.
Select from the catalogue suitable copper cable for this
motor. Dont forget to consider the voltage drop per meter,
the total voltage drop shall not be more that + - 5%.

Is This Answer Correct ?    15 Yes 9 No

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

Answer / 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

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

Answer / shamsher singh

10sqmm cooper

Is This Answer Correct ?    1 Yes 1 No

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

Answer / ramesh insan

As per thumb rule
Power Sq root 3=1.732
Voltage =415
PF=0.8
Cos=0.85

1.732*415*0.8*0.85=488.77

30HP*746W=22380/488.77=45.79 Amp

Is This Answer Correct ?    0 Yes 0 No

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

Answer / amarnath

If its a 2.5Sq.mm Aluminium cable then it can take load
current upto 3Amps and if its Copper cable then it can take
a load current upto 9.4Amps.

And for a 30HP motor the cable size shall be 3.5Core X
16sq.mm Aluminium or 3.5Core X 6sq.mm Copper cable.

Is This Answer Correct ?    17 Yes 23 No

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

Answer / mrudang

we are measure through SWG ( standard wire guage
it measure the crossection of wire
2.5sqmm

Is This Answer Correct ?    13 Yes 20 No

Post New Answer



More Electrical Engineering Interview Questions

why we have to do tan delta test of the transformer oil???

5 Answers  


What is the equivalent circuit of a transformer and its vector diagram?

0 Answers   Bhel, Madhucon,


what is difference between power & distrubution transformer ?

3 Answers  


Dear friends , I am going attend interview for WARTSILA INDIA LIMITED , power plant .Could any 1 pls send me few questions. the area i have to concentrate? please send it to mikalraj@gmail.com. pls help me out

1 Answers  


what is ratio test?

1 Answers  






Please tell me what is the difference between online UPS & OFF line UPS?

2 Answers   HAL,


What is the difference between earth resistance and earth electrode resistance?

1 Answers  


difference between semiconductor & conductor & insulator?

0 Answers  


why voltage is low at reciving end in summer??

4 Answers   JSW,


how is choose &depending upon the load why?

1 Answers   HCL,


what is mean by harmonics?Type of harmonics?

6 Answers  


In secondary transmission i.e., in distribution side, supply for homes are connected through different phases in order to balance the 3 phase load. But in practical we saw nearby house doesn't have power due to single phasing. But other two phases give supply. How it's possible? it doesn't make "single phasing"?

1 Answers  






Categories
  • Civil Engineering Interview Questions Civil Engineering (5075)
  • Mechanical Engineering Interview Questions Mechanical Engineering (4444)
  • Electrical Engineering Interview Questions Electrical Engineering (16600)
  • Electronics Communications Interview Questions Electronics Communications (3915)
  • Chemical Engineering Interview Questions Chemical Engineering (1092)
  • Aeronautical Engineering Interview Questions Aeronautical Engineering (214)
  • Bio Engineering Interview Questions Bio Engineering (96)
  • Metallurgy Interview Questions Metallurgy (361)
  • Industrial Engineering Interview Questions Industrial Engineering (258)
  • Instrumentation Interview Questions Instrumentation (2987)
  • Automobile Engineering Interview Questions Automobile Engineering (332)
  • Mechatronics Engineering Interview Questions Mechatronics Engineering (97)
  • Marine Engineering Interview Questions Marine Engineering (123)
  • Power Plant Engineering Interview Questions Power Plant Engineering (170)
  • Textile Engineering Interview Questions Textile Engineering (575)
  • Production Engineering Interview Questions Production Engineering (0)
  • Satellite Systems Engineering Interview Questions Satellite Systems Engineering (106)
  • Engineering AllOther Interview Questions Engineering AllOther (1377)