LV cable size

300m is not so long to justify step-up and step-down xfr 400/1000V. Use copper and make sure that the load is balanced otherwise, you will require a huge neutral return to carry out of balance current.

thank you for your comments,the load is resdential and easily mangeable,but the genration voltage as i have told earlier that are 400 would u or any body else sugges the proper size eastiated

thanx

Dear Irfan Choudhary,

In order to help with cable size, we would need some 'load` information.

I suggest you 'run the numbers` for the expected load.

You will require a step-down transformer for the residential load in any case.

A step-up transformer for transmission for the 300 M. run could eliminate
the transmission neutral and save a lot of copper balanced against the cost of
the step-up transformer and the increased cost of the higher primary step
down at the residence.

(This assumes you face statutory limits on voltage drop that cannot be
overcome by taping-up at the residence.)

If you want sizes it might be a good idea to tell us

the size of the load.

A coherent Question will elicit the correct answer

i think the usual copper cable would be enough..but don't make it too big..it's definitely not suits (if it's too big)..

My friend, it depends on your power consupmtion ( load.) Just a examle if your load is

400 Vac. 200 Amps. it means approx. 120 kVA. you should use for each phase 120 sqmm2 cupper cable. Mybe your load is 10 kVA. cable size will be less. but the most important thing is voltage dropping. Each 200 mt. your voltage average 8 volts drops. I think you don't need any step up transformer. You can solve your problem with the cable size... good luck with techinal researchs.. :)

thank you respected friend,

further to my quiry my load ia 200kw(residential) approx.365Amps so accordoing to my calculation the voltage drop calculations we must be in need of 300 sq.mm cable for 300mtrs,

Maximum length of LV cable = L = 300 m,

Generated Voltage = V = 400 V

Current per phase = I = 360 Amperes

Assume Cable size of 400 sq. mm.

mV drop per Amp per meter = 0.17

Voltage drop = mV X I X L / 1000

= 0.17 X 360 X 300 / 1000 = 18.36 V

% drop = 18.36 / 400 X 100 = 4.59 % which is acceptable for lighting & domestic loads but not for Electrical motors

hi,

can you say the load approximately

Hello

Irfan ou need to keep the voltage drop < 3% ..