2 core or 3 core

[Sav]

Hi everyone,
just reading and giving myself examples of cables etc to work out cable selection and volt drop ( I know its Friday, but I have to keep reading or I will forget )!!!

If for example you have an swa 3core (brown, grey, black), which , say your running to a supply from a DB board.

On pages 274 onwards, the copper conductors and volt drops etc, would you say the cable is a 1 two core cable, single-phase or 1 three or four core cable, three phase ??

The scenario is 60amp isolator , swa 16mm 3 core ( brown, supply, grey with blue sleeving neutral and black with green/yellow sleeving earth ). 45 meter run along building and in ground, single phase. Abient air temp 30 degrees, Ground temp 20 degrees

Its basically just to see that even though the swa is 3 core, one of the cores (black) will be earth and its single phase.

So what would you base the calculations on ??
Thanks and regards,
Sav

 

[Guest123]

It's classed as a 2 core single phase as you dont include the CPC (3rd core in this instance) as it normally doesn't carry any current.

 

[Sav]

Hi Lenny,
That was exactly my thought, but a friend of mine who is doing a course said his tutor told him its based on 3 core. I insisted that he was wrong, as you said the third core is not carrying any current, so thank you for your much appriciated help !!
Have a big drink on me,
Best regards,
Sav