## Calculations //

### Based On Motor Horse Power HP and Specified Current

Input data: Motor voltage (V L-L), Motor horsepower, Cable Temperature Rating (°C), Ambient Temperature (°C), Cable Length (ft) and Acceptable Voltage Drop (%).

Calculated Values: Operating Current (A), 125% Current per NEC (A), “Zero Length” Cable Size, Acceptable Voltage Drop (V), Actual Voltage Drop (V) and Actual Voltage Drop (%).

### Note//

Conductor ampacities are based on NEC 2008, Table 310.16 (Not more than 3 current carrying conductors in racewary).

 Software: Cable Size Calculations – Based On Motor Horse Power HP and Specified Current Version: – Developer: – Size: 73.5 kB Price: Free Download: Right here | Get Download Updates | Get Technical articles

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1. Shivam singh
Mar 31, 2018

Hii Sir ,

I am confused in Three phase wire size calculation please let me know exact formula for three phase wire size calculation with multicore and single core cable.
For example Load Current – 45 A , Voltage drop – 3 %, Cable Lenght -10 Meter,
Please tell me how to calculate 4-Core Copper cable size for that ? Please do needful
Thanks

2. mustafa
May 30, 2017

hi
lwant aske you about how calculate cable size section if it wase almunium or copper
thank yoy so much

3. Md. Keafayet Ullah
Apr 18, 2017

How can I use cable size for 440 kW load? Please suggest Me?

4. Ram Karan Sharma
Jan 21, 2017

I want to know cable size. I have to install a DG set of 40 KVA capacity and length of cabling about 2000M having one outlet about 4KVA at every 10 M

5. uduman
Mar 11, 2016

Dec 21, 2015

Very nice

7. Joselito Ocampo Paguio
Sep 28, 2015

Sir, Please Can You Explain How To Get Your Answer 19Volts Voltage Drop For 3 Phase And The resistive of copper & Conductivity Of Copper 58 And Aluminum 36 Including Voltage Drop And Voltage Line For Cables Sizing Formula Calculation
Your Most Favorable Response Is Highly Appreciated.

8. ricky
Sep 17, 2015

it doesnt have a calculation for 3-phase motor.

9. prem
Sep 10, 2015

how to find out the Resistivity of copper

10. harry ojeagbase
Apr 19, 2015

I want to know how to determine the sizes of almond cables used in the design of smdb panel

Feb 08, 2015

consider factors for duty of motor-S1,S2,S3…. and AC1,AC2,AC3 etc

12. Dhaval Merchant
Jul 08, 2014

13. naeem hussain
Jun 11, 2014

three ph formula watt/440*1.5 and single phase watt/volt

14. DELOUR
May 09, 2014

Can you send me the calculation spreadsheet for ampere to Cable Size Calculations – Specified Current.with V L-L = 220V and VL-L=415V, I really need.
Please send to my Email- delour07@gmail.com

15. Unis Khan
Apr 10, 2014

Cable sizing formula calculation:-

Data:-
L:- Length of cable in meters =200
P :- Resistivity of copper 0.024(90 deg.C).
Vd:- Voltage drop in 3 ph.=19volts.
3 ph.=1.732.

Apply formula for calculate the area of cable.
Area(mm2)= 1.733*I*L*p/Vd
= 1.732*160*200*0.024/19
= 70 mm2
Note:- 2 for single phase.
1.732 fot three phase.

Above said formula is perfectly correct.
Enjoy it.

M.Sc.Engg.,MIER(UK).
punjab,Pakistan.

• ENGR. SAQIB JAVED
Jun 03, 2014

How you calculate voltage drop in 3-PH is 19? and how it is calculated in case of single phase? My email address is saqibjaved786@hotmail.com

• vishnu
Nov 28, 2015

I have a one dought in apply the cable sizing formula .How u put Resistivity of copper 0.024 and this value 1.732 . If u have a any formula for that value please reply sir .
Thanks

• Laxminarayana arelly
Sep 16, 2016

Dear sir please give me lode calculations formula and voteg drop calculations and cable size calculations please give me reply sir thanku sir

Mar 02, 2014

SIZE OF CABLE FORMULA:-
L= LENGTH OF CONDUCTOR (IN METERS)
10 HP MOTOR 3PH.(10 X 746 =7460 WATTS) ,,, I = P/1.732 X 230 V= 7460/(1,732X230)
=18,72 AMPS
P=7460/PF=7460/0.85 = 8776.47 VA
NOW APPLY THE CABLE SIZING FORMULA:-
AREA mm2= 1.732 X L X VA/(K X Vd xVL)
= 1.732 X 200 X 8776.47/(58 X 6.9 X 230)
= 33 mm2
LENGEND:
L = LENGTH OF CONDUCTOR.(IN METERS)
VA = VOLT AMPERE
K = CONDUCTIVITY OF COPPER 58 AND ALUMINUM 36
Vd = VOLTAGE DROP.
VL = LINE VOLTAGE.

USE ABOVE SAID FORMULA FOR CALCULATE THE SIZE OF CABLE BY EASY WAY.

• ENGR. SAQIB JAVED
Jun 05, 2014

How you calculate voltage drop?

• Manikandan
Jun 26, 2014

Dear sir ,
I have a one doupt in apply the cable sizing formula .How u put conductivity and voltage drop value . If u have a any formula for that value please reply sir .
Thanks

17. yu7aw
Mar 13, 2013

Thank you very much. It will be tremendously useful for my further activity.
Once again, thanks a lot and all the best to all of you, guys !

Aug 01, 2012

Can you send me the calculation spreadsheet for Cable Size Calculations – Based On Motor Horse Power HP and Specified Current.with V L-L = 380V and VL-L=660V, I really need.

19. Hirenkumar
Jun 19, 2012

Dear Edvard,
I found this one of the most useful site for new and experienced enginner.
Thank you verymuch for your efforts and interest.

Sharing of knowledge is always good.

20. intoko@racsa.co.cr
Apr 10, 2012

My security software found the following application with an exploit virus: Cable Size Calculations – Based On Motor Horse Power HP and Specified Current. Please test it and post again.

• Edvard
Apr 10, 2012

It’s not virus for sure. Your security software is overreacting :) This spreadsheet as well as all the others contains VBA (visual basic for applications) part within itself that does the calculation.

21. Sufi Shah Hamid Jalali
Apr 08, 2012

I am an electrical power engineer. EEP is the only place I feel comfortable in. I am really impressed by all the hard work that the whole team go through. I promise to start writing here about Renewable Energies – soon. Thank you all!