Interested to Buy Any Domain ? << Click Here >> for more details...
how to choose the cable size for 100A(is there any formula
please update)
- 6 Answers
- 14471 Views
- I also Faced
- E-Mail Answers
Answer Posted / shirish
Theory for Cable Sizing.
From Ohms law, the voltage drop in an electrical conductor is
V = I R
where
I = Current, amps
R = Resistance, Ohms
The electrical resistance can be derived from the properties of the conductor material.
R = ρ L / A
where
ρ = Resistivity, Ω mm2 /m
L = Length, m
A = Cross sectional area, mm2
Watch the units in the above equation.
The resistance can also be expressed in terms of the material conductivity (ψ) which is just the reciprocal of the resistivity.
R = L / (ψ A)
Table 1. Typical material electrical conductivity
Material Conductivity, ψ
Copper 58
Aluminium 36
Mild Steel 7.7
Combining Ohms law with the resistance expression, we get.
V = (I L) / (ψ A)
Now, we can define an acceptable voltage drop in a conductor. I have calculated the voltage drop that was used in several published tables and get around 5.5 Volts.
We could therefore re-arrange this equation to give the cable size. But cables come in standard sizes measured in mm2. In addition, you also need to consider the maximum current for each cable size.
Table 2. Conductor sizes and maximum currents
Cable Size, mm2 1.5 2.5 4 6 10 16 25 35 50 70 95 120 150 185 240 300
Maximum current, A 13 21 28 36 46 61 81 99 125 160 195 220 250 285 340 395
So, the theory is relatively simple, let us now see how to use the program.
| Is This Answer Correct ? | 0 Yes | 2 No |
Post New Answer View All Answers
If a current -8+6sin6t is flowing three ammeter, one is a centre zero PMMC meter, one is true rms meter and one is moving iron meter. What are the reading of these three meter respectively?
area control error
Explain the working of any one cutting machine
I am an American living in Vietnam and I have recently gotten a refrigerator from Japan and it is rated for 100 vac, but the power here is 220 so I bought a voltage stabilizer it has a 1 kva output rating. Can you please tell me what the amperage is? I'm confused and without a working fridge.
use of choke in APFC panels
What is cross over distortion? How it can be eliminated?
Why 1/3 is used in symmetrical components?
how is the testing of an REF relay? what are the test REF circuit having?
Where I can get the sample question for post of Junior engineer electrical-II For RRB Bhubaneswar.
In both 600/1000 V cable and 450/750 V cable, we can supply 415 V. However for distribution, all utilities are using only 600/100 V instead of 450/750 V. What is the reason?
What is principle of Floroscent tube 36watt.
what is formula for zero phase sequence of nuetal earthing transformer of 6.6 kv
What is quadrantal symmetry?
Will any motor burn if voltage provided is lesser than the rated voltage???? If yes, then how is speed control possible with voltage control
What is the principle of HIGH SPEED DIRECT DRIVE MOTOR ?
