How to calculate cable sizes in sq.mm. with using motor KW?
Any formula there?

Answers were Sorted based on User's Feedback



How to calculate cable sizes in sq.mm. with using motor KW? Any formula there?..

Answer / abid

Normally for the circuit breaker calculation we multiply our motor's current into 125% for example if a motor 5HP operates in 8amps we multiply8*125%(10) so the breaker size will be 8+10 18amps or 20 amps.
and for the cable size we multiply breakers amp*1.5
=27
so for 5hp 3ph motor suitable breaker is 20amps
and the suitable cable 4sqmm

Is This Answer Correct ?    3 Yes 0 No

How to calculate cable sizes in sq.mm. with using motor KW? Any formula there?..

Answer / naresh

1sqmm will withstand upto 4amps.

(i.e) 1sqmm = 4amps

Is This Answer Correct ?    3 Yes 0 No

How to calculate cable sizes in sq.mm. with using motor KW? Any formula there?..

Answer / sibu

One has to consider the distance of the motor and power supply sources too. In short if the motor distance is let say 400 meters from the power supply then voltage drop will be more and in that case u need to consider bigger size cable then what u find in calculation

Is This Answer Correct ?    1 Yes 0 No

How to calculate cable sizes in sq.mm. with using motor KW? Any formula there?..

Answer / k.l.lim

ex 10kw 3 phase ac motor,
10kw x 1.74 = 17.4 amp
MCB using 25 amp/30 amp 3 pole(C)
Motor using star-delta/overload setting 0.58 = 10.1 amp
cable size = 6x2.5mm2/1c pvc copper cable

if using soft starter
MCB using 25amp/30amp 3 pole MCB(C)
cable size = 3x4mm2/1c pvc copper cable

cable size :calculate include starter overload setting
(right or wrong,thank's)L

Is This Answer Correct ?    17 Yes 20 No

How to calculate cable sizes in sq.mm. with using motor KW? Any formula there?..

Answer / pedro

what's wrong with you guys. You dont even know how to spell
correctly. Please improve on that. Its not only about idea
but also on how you convey it. Damn!

Is This Answer Correct ?    6 Yes 16 No

How to calculate cable sizes in sq.mm. with using motor KW? Any formula there?..

Answer / raja

THE ABOVE SAID IS WRONG , ITS A THUMB RULE I USE TO FALLOW
1 sqmm = 5A & endangering amps withstand is 8A for alu
(sqmm * 1.87A)for cu sqmm *2

Is This Answer Correct ?    25 Yes 44 No

How to calculate cable sizes in sq.mm. with using motor KW? Any formula there?..

Answer / ibrahim

for cooper 2.5 mm for 1 amp
for aluminum 1.5 mm for 1 amp

Is This Answer Correct ?    11 Yes 30 No

How to calculate cable sizes in sq.mm. with using motor KW? Any formula there?..

Answer / hemant

Normally copper has more conductivity than aluminium. So it
is actually reverse. 1.5 mmsqr for copper and 2.5 mm sqr
for alu

Is This Answer Correct ?    47 Yes 89 No

Post New Answer

More Electrical Engineering Interview Questions

What are the protective devices in a DC/AC motor starter?

1 Answers   CTS,


what happens when parallel resonance occurs?

2 Answers  


What is the minimum IR value of HT/ LT cable? Pls post separetely!!!!!

0 Answers   Bhel,


What is the technical formula to calculate the load taken by a motor in Amperes ?

2 Answers  


In the UVR(Under Voltage Relay) there is a knob for the hysteresis setting. what is this setting? its threshold is given from 5% to 50%. please help me....

2 Answers  






what is the principle of synchronous motors?

3 Answers   The Grand,


What Happen When We provide Dc Supply to Ac Motor

6 Answers  


Pl.brief me about Electrical power distribution system from Main generating station to Industry.What is the use of in between station.

0 Answers   ARDE,


how to calculate the settings for shaft ct protn in hydro generators

0 Answers  


What is FM200 Gas??Applications........

0 Answers   Emerson,


What will happened, if field voltage change with 220 voltage to 110 voltage for a dc shunt motor?

1 Answers  


The capacitive reactance of a capacitor of 1/(2(PI)) F at 10^3 H is

0 Answers  


Categories
  • Civil Engineering Interview Questions Civil Engineering (5085)
  • Mechanical Engineering Interview Questions Mechanical Engineering (4451)
  • Electrical Engineering Interview Questions Electrical Engineering (16632)
  • Electronics Communications Interview Questions Electronics Communications (3918)
  • Chemical Engineering Interview Questions Chemical Engineering (1095)
  • Aeronautical Engineering Interview Questions Aeronautical Engineering (239)
  • Bio Engineering Interview Questions Bio Engineering (96)
  • Metallurgy Interview Questions Metallurgy (361)
  • Industrial Engineering Interview Questions Industrial Engineering (259)
  • Instrumentation Interview Questions Instrumentation (3014)
  • Automobile Engineering Interview Questions Automobile Engineering (332)
  • Mechatronics Engineering Interview Questions Mechatronics Engineering (97)
  • Marine Engineering Interview Questions Marine Engineering (124)
  • Power Plant Engineering Interview Questions Power Plant Engineering (172)
  • Textile Engineering Interview Questions Textile Engineering (575)
  • Production Engineering Interview Questions Production Engineering (25)
  • Satellite Systems Engineering Interview Questions Satellite Systems Engineering (106)
  • Engineering AllOther Interview Questions Engineering AllOther (1379)