Interested to Buy Any Domain ? << Click Here >> for more details...
How we find the size of cable if we know the current
- 2 Answers
- 22744 Views
- Gemscab, I also Faced
- E-Mail Answers
Answer Posted / aju
We can choose the cable according to the current rating
after considering overload and voltage drop factors
Usually cables are loaded upto 75-80 % of the rating
specified by manufacturer ..
For instance, if you need to choose a cable for a current
rating of 25 A, we can simply choose 6 sq.mm cable since it
can carry 35 Amps. It is desirable not to use 4 sq.mm cable
which has a current rating of 28 A since it has no
sufficient spare capacity for overload condition.
Again, the cable size also depends upon the voltage drop
which depends upon the length of the cable....
usually voltage drop must be within 3-5 % range.If it
exceeds this limit then next higher size must be used until
it satisfies the 3% range
Eg. for calculation of voltage drop in 25A, 240V single
phase feeder having 150M length
Voltage drop/Ampere/Metre for 35 Sq.mm cable=2.1mV
Voltage drop= (2.1x25x150)/1000 =7.88V
% Voltage drop= (7.88x100)/240 = 3028%
Since it exceeds the 3% range, take next cable size
Voltage drop of 50Sq.mm cable= (1.6x25x150)/1000 =6V
% Voltage drop =(6x100)/240 =2.5%
Hence, we can select 50Sq.mm cable
| Is This Answer Correct ? | 74 Yes | 15 No |
Post New Answer View All Answers
Which motor is 3.3 or 11kV more reliable, in terms of efficeancy,maintenance, reliability.
why would the rotor rotate at sub synchronous speed against the direction of rotating flux when d rotor of 3 phase IM is connected to 3 phase balanced supply and the stator windings are shortcircuited ??
At what speed an electric car can run with 2 HP motor of weighing 400 kg?
what is the diference between the 4pole & 6pole DC Motors & what is advantage 6pole over the 4pole ?
what is gridrotor resistance starter
what would u consider to be the basic purchase order information you would need to proceed with a cable inspection assignment?
A 50Hz,4-pole,3-phase,star-connected synchronous motor has a synchronous reactance of 12ohmsper phase and negligible armature resistances.the excitation is such as to give an open-circuit voltage of 13.2kilovolt.the motor is connected to 115kilovolt, 50hertz supplying. what maximum load can be the motor torque,line current and power factor?
what is circuit recombiner and how it is different from circuit breaker
what types of cable used in underground coal mining?
Why field rheostat is kept in minimum position?
what is the calculation involved to design the heater to heat 10KL of water in temperature control unit?
Difference between RCCB, RCBO and ELMCB.
what are the reasons of CT circuit faulty in busbar protection scheme?
what is feed back and what are feed back amplifiers?
who invented active elements? plz give me the complte details of active elements...
