if we want ot select cable size with reference to load
current it take than what is the formula and it is same for
aluminium or copper?

Answer Posted / mahesh sali

while selection of cable u should followed the below steps ;

1) cal. the full load current If.L= ( kw / 1.732 x v x
p.f. )

Assume the voltage drop of system as per application says
for motor it should be 10% Vd = 10%

2) Vd = ( 10/100) * v

3) Vd/ph. = ( Vd/1.732 )

4) R = vd/ph./IF.L

5) R-Rho*L/A

Assume , for Copper cable Rho = 1.72 e-8 Ohm-m
L = Length of cable
Base on the above assumation u can easily cal. the size of
cable.

After cal. the cable size , add. 25% extra in ur cal. the
cable size .

Thanking u

Is This Answer Correct ?    2 Yes 0 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

what is The difference between national electrical code and I.S.Code (electrical) and what is the value of NEC in electrical engineering field

1474


234 MVA Generator 3 phase Short circuit current Values required? Gen set Rating-234 MVA, Gen Voltage-18kv, PF;0.8, Xdv:23.5 %, Transformer Rating-18/380KV, 680MVA,Yndd1 two winding, Step up TR, ZT:35.50 %,X/R 4.33 Gen CB Position, CB open ,Disconnected open, Generator Running Voltage 18 Kv, Bi mistakes generator side earth switch Closed during that time short circuit current level in 3 Phase required, and how to test on site 234MVA Generator Short circuit current,

1738


USE OF 8 WAY PAN ASSEMBLY

1495


what is your aim

1442


why do we have spikes enough to burn electronic boards, when generators are not grounded

1322






WHY THE COLOR OF OUTDOOR TRANSFORMER IS BLUE ONLY???

1638


how to make an earthing certificate

1760


Explain the method to keep noises low in a control system?

653


if an insulated power and control cables of a running gas diesel gensets laid direct in an open trench i.e, trench bed is not rcc of a power house in which rain water, spillage water alwas exists and all power control cables remains submerged even when gas gensets of 480 kw each runningin on load. These power &control cables runs from power house to switchgear room through these trenches in which water remains most of the time. pl explain its merit & de-merit

1405


How do you select the pickup value of the relay?

810


Can an inverter be used as a converter? How?

1471


can i connect REF and Differencial relay in 1 CT core for transformer protection?

1463


WHY THREE PHESE SYSTEM VOLTAGE APPLIED IN 440 VOLT

1916


Given a collection of points P in the plane, a 1-set is a point in P that can be separated from the rest by a line; i.e. the point lies on one side of the line while the others lie on the other side. The number of 1-sets of P is denoted by n1(P). The maximum value of n1(P) over all configurations P of 19 points in the plane is 18

1650


why power not passes in plastic and rubber material

1538