Urgent..changing cu to al cable..

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abusabbath

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im newbie here...

what formula to calculate the voltage drop..

i want to change the cable...

 

abusabbath

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thanks for the response...

my problem is..i want to change existing cu cable to aluminum cable. i really need the formula and how to get the table of voltage drop per ampere per metre for both cable.

this is a detail :

cu cable size : 4core 185 sq. mm

length : 180m

current : 250A

phase : 3 phase (415)

change to :

al cable size : ????

length: 180m

current : 250A

phase : 3 phase (415)

**this for underground cable

 

steptoe

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if you really REALLY want to do it simply take the resistance of the copper cable and see just how BIG an ally cable you need to get the same low resistance!!!!

it WILL scare you.

I really cant be ****d to work it out for you as its such a stoopid suggestion, and I mean that in the best possible way.

but it is totally STUPID to even think about doing this.!!!!

 

steptoe

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u could be right badger.!

or else some thick jesuit ****brain wanting to weigh in the copper

either way its the stoopidest thing ive ever heard.

 

abusabbath

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i know the cable must be big but the price low...i have spare aluminium cable..

why u too rude..

r u smart enought??

 

sparkyrj

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allluminium cable is has almost twice the resistance of the same size cable in copper so it doesnt seem worthwile changing it. Also there may be issues with the terminals, as there can be corrosion problems with ali cable in brass terminals .

 

benji

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you can get bimetal lugs either pin type or palm type but lets face it this thread is going nowhere

yours benji

 

steptoe

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quick calc for you then

al cable required

1875mm2 per ph,

but,

this will depend on you being able to calc your current balance, and are you also changing the earth conductor?

I dont think it will be possible to do so on this length of run to use al in place of copper, NP.

and you REALLY THINK you can still get cable that size?????

going by the limited info you provided thats the min size you require, you didnt state load types etc.....

 

steptoe

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ps,

NO such voltage as 415 in the UK,

so if you are refering to elsewhere then even my rough rule of thumb calcs are miles out to meet other regs......

 

abusabbath

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im sory..my mistake.

lv cable cant reach 500 meter...too much voltage drop...

thanks for the correction...

 
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