Calculate Conduit Size for Wires / Cables
December 20, 2015 19 Comments
Example: Calculate Size of Conduit (Hume Pipe) for Following Size of Cables
- 5 No’s of 3.5 Core 50 Sq.mm XLPE Cable. Diameter of cable is 28mm
- 3 No’s of 3.5 Core 185 Sq.mm XLPE Cable. Diameter of cable is 54mm
|
% Fill Up Area of Conduit |
|
| No of Cables | % Fill up Area of Conduit |
| Up to 2 No’s | 53% |
| 2 No’s | 31% |
| More Than 2 No’s | 40% |
Calculations:
- Area of Cable =3.14 X (Diameter/2)2
- Area of 50 Cable =3.14X (28/2)2 =615.44 Sq.mm
- Total Area of 50 Cable=No of Cable X Area of Each Cable
- Total Area of 50 Cable=5X615.44 =3077.2
- Area of 185 Cable =3.14X (54/2)2 = 2289 Sq.mm
- Total Area of 185 Cable=No of Cable X Area of Each Cable
- Total Area of 185 Cable=3X2289=6867.18
- Total Area of Conductor= Total Area of 50 Cable+ Total Area of 185 Cable
- Total Area of Conductor=3077.2+6867.18
- Total Area of Conductor=9944 Sq.mm
- Suppose We Select 150mm Diameter Hume Pipe
- Total area of 150 mm Diameter Hume Pipe =3.14 X (Diameter/2)2 =3.14X(150/2)2.
- Total area of 150 mm Diameter Hume Pipe=17662 Sq.mm.
- % Fill up Area of Conduit due to Cables as per above Table is 40%
- Actual Fill up Area of Hume Pipe =40% X Area of Conduit =40% X 17662
- Actual Fill up Area of Hume Pipe =7065 Sq.mm
- Required No of Conduit = Total Area of Cables / Actual Fill up Area of Conduit
- Required No of Conduit = 9944 / 7065
- Required No of Conduit= 2 No’s
- Suppose We Select 3000mm Diameter Hume Pipe
- Total area of 300 mm Diameter Hume Pipe =3.14 X (Diameter/2)2 =3.14X(300/2)2.
- Total area of 150 mm Diameter Hume Pipe=70650 Sq.mm.
- Actual Fill up Area of Hume Pipe =40% X Area of Conduit =40% X 70650
- Actual Fill up Area of Hume Pipe =28260 Sq.mm
- Required No of Conduit = Total Area of Cables / Actual Fill up Area of Conduit
- Required No of Conduit = 9944 / 28260
- Required No of Conduit= 1 No’s
Results:
- Either We Select
- 2 No’s of 150 mm Diameter Conduit /Hume Pipe or
- 1 No’s 300 mm Diameter Conduit /Hume Pipe
JIGNESH PARMAR
In the formula area u have written radius/2 but it shuld be diameter/2. So please update
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The fully charged batteries 12V battery has a voltage of 12.65 Volts
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Regards
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Export Manager
Pacific Batteries Limited
Lot 20/ 21 Wailada Industrial Estate
P.O.Box 3082
Lami – Fiji Islands
Phone : +679 3362708 / 3362255
Mobile : +679 9990081
Dear sir,
I need 440 kV transmission line construction details, design criteria, and maintenance manual. Or standard.
.
Regards,
Gajendiran M
Dear sir how to find out the steam turbine generator efficiency.20MW,11KV,1358A,0.8lag,1500RPM.Thanking you sir.
knowledgeable information
Thank you. This is useful for those who are willing to calculate conduit size.
Jignesh would like buy your Electrical tools.Can I get the C.D for it
sir, i have got resistance between one of phase cable and ground 10 giga ohms while other phases are at more than 100.Is there any problem in energizing the cable.
cable is between Package substation .Is there any problem to energize the loop with out connecting load.
Thanks for giving such valuable information .
Sir what is the % fillup area of conduit pls rply sir
hi sir what is runs in a cables…for ex:1RUNS/2RUN and how we find this one..
Is that any IS/Electrical standards for Conduit Size for Wires / Cables??
Akhilesh Dubey
very good useful information thanks
how to find the phase to phase bus bar clearance for low voltage.
“5 No’s of 3.5 Core 50 Sq.mm XLPE Cable. Diameter of cable is 28mm” Here i dont understand 3.5 core and diameter of cable 28mm. please clear me. I can understand 50 sq mm cable area then how come diameter of cable 28 mm.
First calculate 50sqmm diameter.
Area = pi*r^2
50= 3.14*r^2
r= 3.99mm. Diameters is 7.98
So if 3.5 core cable is = core*dia
= 3.5*7.98 =27.93 =28mm
Dear Sir I want to know about of tray trunking in cable / wire calculation
Thanks for giving such valuable information.
Thanks much for fruitful information. I would like to know resistance /km & reactance/km as per core dia or area . Would you help me where the chart/data can be found.