parallel cables

[keith@kbw]

can any help me, i need to install 200amp three phase supply at 135m long, i wish to run two smaller cable insted of one large size cable, so can any one tell how to calculate for parallel cables supply.

 

[Had8Lives]

Don't know if you will get a cable big enough for such a long run. Would probably be best running two 100A Supplies depending on what you are supplying.

 

[keith@kbw]

we are supplying a water teatment plant, which needs 120amps 3 phase+N and we have to run parallel cable plus earth cable, what i am looking for is formulas to calaculate cables sizes.

 

[Mac]

we are supplying a water teatment plant, which needs 120amps 3 phase+N and we have to run parallel cable plus earth cable, what i am looking for is formulas to calaculate cables sizes.

American Wire Gauge table and AWG Electrical Current Load Limits

 

[Rulin]

for your 200amp supply

185mm 4 core will be fine....(thats in the ground)
150mm 4core on tray (perforated)

hope that helps

 

[keith@kbw]

thank you all your help, but can one help me with the formulas and calulations ?

 

[benji]

are you saying 200a= 1x 185 4c or 2x 185 4c

yours benji

 

[Mac]

thank you all your help, but can one help me with the formulas and calulations ?

Don't think you will actually find any calculations but try this.
Electrical Reference- Electronic Formulas, Calculations, Design

 

[baldsparkies]

Max demand and diversity along with possibly power factor correction to be considered, The link below could prove usefull to you hope it helps.

cablecalculation

Also appendix 4 of the big red book will give you all you need with regards to calcs rating factors ect.

 

[Mac]

Max demand and diversity along with possibly power factor correction to be considered, The link below could prove usefull to you hope it helps.

cablecalculation

Also appendix 4 of the big red book will give you all you need with regards to calcs rating factors ect.

Looked at this link earlier on.You have to pay for this one.

 

[baldsparkies]

Looked at this link earlier on.You have to pay for this one.

Sorry Mac thought it contained a useable demo mate

 

[keith@kbw]

thank you all for information.

 

[benji]

I would think a 185mm is a bit over and without checking would have thought a 4c 120mm
would be ok or 2x 4c 70mm in parallel also i believe cables in a trench underground benifit from the natural cooling of the soil
yours benji

 

[keith@kbw]

thank you, for our information, but i need to show this on paper thats why i need calculation or formuas.

 

[Wotsit]

Do you have all the details of equipment you are connecting? Supply over 100A really should take into account Xl and Xc so a bit of j notation might be required. As for the two cables thing if your calcs ask for a 400mm2 cable for example and you want to use two for ease of installation just use 2 x 200mm2.

 

[benji]

400mm? have you ever pulled a 400mm 4c ,i,ve pulled 300mm 4c & singles upto 1000mm
but your talking high current way above the 120a that started this thread .My college days
are long gone but i still reckon 2x 70mm 4c will do it.
But back to the original thread it doesn,t give you a clue as to how the cables could be installed so you don,t know what the correct factor to apply so more info needed

yours benji


sorry 120a should read 200a but still reckon 2x704c

benji

 

[Wotsit]

400mm? have you ever pulled a 400mm 4c ,i,ve pulled 300mm 4c & singles upto 1000mm
but your talking high current way above the 120a that started this thread .My college days
are long gone but i still reckon 2x 70mm 4c will do it.
But back to the original thread it doesn,t give you a clue as to how the cables could be installed so you don,t know what the correct factor to apply so more info needed

yours benji


sorry 120a should read 200a but still reckon 2x704c

benji

No no, i was just using the size as an example and showing to divide the CSA by two for the correct cable size.