## Calculation of voltage drop and cable size for motor/electrical load

- Calculate Voltage drop of Cable.
- Calculate Size of Cable.
- Calculate Current Capacity of Cable.

Software: | Cable designing program |

Version: | 22.8.2012 |

Developer: | Jignesh Parmar |

Size: | 99 Kb |

Price: | Free |

Download: | Right here | Get Download Updates | Get Technical articles |

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Page edited by E.C. (Google).

Parag Chamuah

Thanks for the work you have shared. I have few queries:

1.How do we know what is the phase value(φ)?

2.What is demand factor specifically?

bdthang

Very useful. It help me a lot!

kolumb

There is something wrong with the cable data – it’s impossible 3 different type cables with same Conductor Area, same matherial, to have 3 different Resistance (ohm/km).

Example – look first 3 cable types – PVC flexible, PVC insulated and XLPE insulated, for the same Conductor area (by example 1cX6), both Copper, resistance for the fist is 3.3ohm/km, for the second is 3,69ohm/km and the third is 1.53ohm/km.

May be the last one uses a super copper, twice better than first 2

ENGR.MUHAMMAD YOUNAS KHAN

dear sir

I want to submit the formulas of cable sizing to those persons which are searching here and there.I appreciate of your current website which are publishing my cable sizing ideas.I am submiting another voltage drop and cable sizing formula.

1- Vd = 1.732 x I X L X PF/ (Area mm2 x conductivity of copper) ———-FORMULA 1

2- Area(mm2) = 1.732 x I X LX PF/(Vd x conductivity of copper) ———–FORMULA 2

WHERE:-

1.732 FOR THREE PHASE.

2 FOR SINGLE PHASE.

I = LOAD CURRENT.

L= LENGTH OF CABLE.

PF= POWER FACTOR.

Vd= VOLTAGE DROP.

CONDUCTIVITY OF COPPER AT 90 DEG.C = 41.66

CONDUCTIVITY OF ALUMINUM AT 90 DEG.C =25.64

DATA:-

1.732 FOR THREE PHASE.

I = 160 AMPS.

L= 200 METERS.

PF= 0.85

FIRSTLY WE CALCULATE THE VOLTAGE DROP.

Vd = 1.732 x 160 x 200 x 0.85/(70 mm2 x 41.66)

= 16.1547 volts —————(1) for copper conductor.

Area(mm2)b= 1.732 x 160 x 200 x 0.85/(16.1547 x 41.66)

= 70 mm2 ———-(2) for copper conductor.

if you want to use Aluminum conductor, apply conductivity of Akuminum which is above said.ABOVE CALCULATIONS ONLY FOR THREE PHASE.

FROM

ENGR.MUHAMMAD YOUNAS KHAN

M.SC.ENGG.MIEE(UK)

WAZIRABAD CITY, PUNJAB,PAKISTAN.

thiru

calc is wrong.Diff cable size should apear for Al & Cu.

osman

please send me

Kingsley

Very useful, Thanks.